diff --git a/conanfile.py b/conanfile.py
index 524cd6a1d..f34a966c7 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -9,7 +9,7 @@
 
 class HomestoreConan(ConanFile):
     name = "homestore"
-    version = "6.4.62"
+    version = "6.4.63"
 
     homepage = "https://github.com/eBay/Homestore"
     description = "HomeStore Storage Engine"
diff --git a/docs/imgs/Child_Node_Merge_1.png b/docs/imgs/Child_Node_Merge_1.png
index d9329bd08..cbc5c5d09 100644
Binary files a/docs/imgs/Child_Node_Merge_1.png and b/docs/imgs/Child_Node_Merge_1.png differ
diff --git a/src/include/homestore/btree/btree.hpp b/src/include/homestore/btree/btree.hpp
index 2ef1e1d44..7b90519b6 100644
--- a/src/include/homestore/btree/btree.hpp
+++ b/src/include/homestore/btree/btree.hpp
@@ -154,7 +154,7 @@ class Btree {
     virtual btree_status_t transact_nodes(const BtreeNodeList& new_nodes, const BtreeNodeList& freed_nodes,
                                           const BtreeNodePtr& left_child_node, const BtreeNodePtr& parent_node,
                                           void* context) = 0;
-    virtual btree_status_t on_root_changed(BtreeNodePtr const& root, void* context) = 0;
+    virtual btree_status_t on_root_changed(BtreeNodePtr const &root, BtreeNodePtr const &freed_root, void *context) = 0;
     virtual std::string btree_store_type() const = 0;
 
     /////////////////////////// Methods the application use case is expected to handle ///////////////////////////
diff --git a/src/include/homestore/btree/detail/btree_internal.hpp b/src/include/homestore/btree/detail/btree_internal.hpp
index 67b33b089..8989a2d5d 100644
--- a/src/include/homestore/btree/detail/btree_internal.hpp
+++ b/src/include/homestore/btree/detail/btree_internal.hpp
@@ -245,7 +245,9 @@ struct BtreeConfig {
     uint8_t m_split_pct{50};
     uint32_t m_max_merge_nodes{3};
 #ifdef _PRERELEASE
-        uint64_t m_max_keys_in_node{0};
+    // These are for testing purpose only
+    uint64_t m_max_keys_in_node{0};
+    uint64_t m_min_keys_in_node{0};
 #endif
     bool m_rebalance_turned_on{false};
     bool m_merge_turned_on{true};
diff --git a/src/include/homestore/btree/detail/btree_mutate_impl.ipp b/src/include/homestore/btree/detail/btree_mutate_impl.ipp
index 209b35558..c08422068 100644
--- a/src/include/homestore/btree/detail/btree_mutate_impl.ipp
+++ b/src/include/homestore/btree/detail/btree_mutate_impl.ipp
@@ -227,7 +227,7 @@ btree_status_t Btree< K, V >::check_split_root(ReqT& req) {
     root = std::move(new_root);
 
     // We need to notify about the root change, before splitting the node, so that correct dependencies are set
-    ret = on_root_changed(root, req.m_op_context);
+    ret = on_root_changed(root, nullptr, req.m_op_context);
     if (ret != btree_status_t::success) {
         free_node(root, locktype_t::WRITE, req.m_op_context);
         unlock_node(child_node, locktype_t::WRITE);
@@ -236,9 +236,9 @@ btree_status_t Btree< K, V >::check_split_root(ReqT& req) {
 
     ret = split_node(root, child_node, root->total_entries(), &split_key, req.m_op_context);
     if (ret != btree_status_t::success) {
+        on_root_changed(child_node, root, req.m_op_context); // Revert it back
         free_node(root, locktype_t::WRITE, req.m_op_context);
         root = std::move(child_node);
-        on_root_changed(root, req.m_op_context); // Revert it back
         unlock_node(root, locktype_t::WRITE);
     } else {
         if (req.route_tracing) { append_route_trace(req, child_node, btree_event_t::SPLIT); }
diff --git a/src/include/homestore/btree/detail/btree_node.hpp b/src/include/homestore/btree/detail/btree_node.hpp
index a3285ef35..b516988d7 100644
--- a/src/include/homestore/btree/detail/btree_node.hpp
+++ b/src/include/homestore/btree/detail/btree_node.hpp
@@ -37,6 +37,7 @@ struct transient_hdr_t {
     /* these variables are accessed without taking lock and are not expected to change after init */
     uint8_t leaf_node{0};
     uint64_t max_keys_in_node{0};
+    uint64_t min_keys_in_node{0}; // to specify the threshold for triggering merge
 
     bool is_leaf() const { return (leaf_node != 0); }
 };
@@ -116,6 +117,7 @@ class BtreeNode : public sisl::ObjLifeCounter< BtreeNode > {
         m_trans_hdr.leaf_node = is_leaf;
 #ifdef _PRERELEASE
         m_trans_hdr.max_keys_in_node = cfg.m_max_keys_in_node;
+        m_trans_hdr.min_keys_in_node = cfg.m_min_keys_in_node;
 #endif
 
     }
@@ -299,6 +301,7 @@ class BtreeNode : public sisl::ObjLifeCounter< BtreeNode > {
 
     template < typename K >
     K get_first_key() const {
+        if (total_entries() == 0) { return K{}; }
         return get_nth_key< K >(0, true);
     }
 
@@ -333,6 +336,7 @@ class BtreeNode : public sisl::ObjLifeCounter< BtreeNode > {
 
     // uint32_t total_entries() const { return (has_valid_edge() ? total_entries() + 1 : total_entries()); }
     uint64_t max_keys_in_node() const { return m_trans_hdr.max_keys_in_node; }
+    uint64_t min_keys_in_node() const { return m_trans_hdr.min_keys_in_node; }
 
     void lock(locktype_t l) const {
         if (l == locktype_t::READ) {
@@ -392,6 +396,12 @@ class BtreeNode : public sisl::ObjLifeCounter< BtreeNode > {
             }
             fmt::format_to(std::back_inserter(str), "]");
         }
+
+        // Should not happen
+        if (this->is_node_deleted()) {
+            fmt::format_to(std::back_inserter(str), " **DELETED** ");
+        }
+
         return str;
     }
 
@@ -527,6 +537,9 @@ class BtreeNode : public sisl::ObjLifeCounter< BtreeNode > {
 
     virtual uint32_t occupied_size() const { return (node_data_size() - available_size()); }
     bool is_merge_needed(const BtreeConfig& cfg) const {
+        if (min_keys_in_node()) {
+            return total_entries() < min_keys_in_node();
+        }
 #if 0
 #ifdef _PRERELEASE
        if (iomgr_flip::instance()->test_flip("btree_merge_node") && occupied_size() < node_data_size) {
diff --git a/src/include/homestore/btree/detail/btree_node_mgr.ipp b/src/include/homestore/btree/detail/btree_node_mgr.ipp
index a5b0317de..3b2383dd2 100644
--- a/src/include/homestore/btree/detail/btree_node_mgr.ipp
+++ b/src/include/homestore/btree/detail/btree_node_mgr.ipp
@@ -42,7 +42,7 @@ btree_status_t Btree< K, V >::create_root_node(void* op_context) {
     }
 
     m_root_node_info = BtreeLinkInfo{root->node_id(), root->link_version()};
-    ret = on_root_changed(root, op_context);
+    ret = on_root_changed(root, nullptr, op_context);
     if (ret != btree_status_t::success) {
         free_node(root, locktype_t::NONE, op_context);
         m_root_node_info = BtreeLinkInfo{};
diff --git a/src/include/homestore/btree/detail/btree_remove_impl.ipp b/src/include/homestore/btree/detail/btree_remove_impl.ipp
index 82213dcc6..6b0d78a5f 100644
--- a/src/include/homestore/btree/detail/btree_remove_impl.ipp
+++ b/src/include/homestore/btree/detail/btree_remove_impl.ipp
@@ -199,7 +199,7 @@ btree_status_t Btree< K, V >::check_collapse_root(ReqT& req) {
         goto done;
     }
 
-    ret = on_root_changed(child, req.m_op_context);
+    ret = on_root_changed(child, root, req.m_op_context);
     if (ret != btree_status_t::success) {
         unlock_node(child, locktype_t::WRITE);
         unlock_node(root, locktype_t::WRITE);
@@ -476,7 +476,6 @@ btree_status_t Btree< K, V >::merge_nodes(const BtreeNodePtr& parent_node, const
             ++idx;
         }
 #endif
-
         ret = transact_nodes(new_nodes, old_nodes, leftmost_node, parent_node, context);
     }
 
diff --git a/src/include/homestore/btree/detail/simple_node.hpp b/src/include/homestore/btree/detail/simple_node.hpp
index 1f4c30e32..fecc04e2e 100644
--- a/src/include/homestore/btree/detail/simple_node.hpp
+++ b/src/include/homestore/btree/detail/simple_node.hpp
@@ -229,8 +229,9 @@ class SimpleNode : public VariantNode< K, V > {
         }
         return str;
     }
+
     std::string to_dot_keys() const override {
-        return to_dot_keys_impl(std::is_same<K, uint64_t>{});
+        return to_dot_keys_impl(std::is_same<decltype(std::declval<K &>().key()), uint64_t>{});
     }
 
     std::string to_dot_keys_impl(std::false_type) const {
diff --git a/src/include/homestore/btree/mem_btree.hpp b/src/include/homestore/btree/mem_btree.hpp
index ce606fc5a..4b3ea6f56 100644
--- a/src/include/homestore/btree/mem_btree.hpp
+++ b/src/include/homestore/btree/mem_btree.hpp
@@ -81,6 +81,8 @@ class MemBtree : public Btree< K, V > {
         return btree_status_t::success;
     }
 
-    btree_status_t on_root_changed(BtreeNodePtr const&, void*) override { return btree_status_t::success; }
+    btree_status_t on_root_changed(BtreeNodePtr const &, BtreeNodePtr const &, void *) override {
+        return btree_status_t::success;
+    }
 };
 } // namespace homestore
diff --git a/src/include/homestore/index/index_table.hpp b/src/include/homestore/index/index_table.hpp
index 2bec275e3..08c36a767 100644
--- a/src/include/homestore/index/index_table.hpp
+++ b/src/include/homestore/index/index_table.hpp
@@ -78,7 +78,8 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
     }
 
     void destroy() override {
-        Btree< K, V >::destroy_btree(nullptr);
+        auto cpg = cp_mgr().cp_guard();
+        Btree<K, V>::destroy_btree(cpg.context(cp_consumer_t::INDEX_SVC));
         m_sb.destroy();
     }
 
@@ -130,13 +131,16 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
         idx_buf->m_dirtied_cp_id = cpg->id();
         BtreeNodePtr bn = BtreeNodePtr{n};
 
-        LOGTRACEMOD(wbcache, "repair_node cp={} buf={}", cpg->id(), idx_buf->to_string());
-        repair_links(bn, (void*)cpg.context(cp_consumer_t::INDEX_SVC));
+        // Only for interior nodes we need to repair its links
+        if (!bn->is_leaf()) {
+            LOGTRACEMOD(wbcache, "repair_node cp={} buf={}", cpg->id(), idx_buf->to_string());
+            repair_links(bn, (void *) cpg.context(cp_consumer_t::INDEX_SVC));
+        }
 
         if (idx_buf->m_up_buffer && idx_buf->m_up_buffer->is_meta_buf()) {
             // Our up buffer is a meta buffer, which means that we are the new root node, we need to update the
             // meta_buf with new root as well
-            on_root_changed(bn, (void*)cpg.context(cp_consumer_t::INDEX_SVC));
+            on_root_changed(bn, nullptr, (void *) cpg.context(cp_consumer_t::INDEX_SVC));
         }
     }
 
@@ -223,7 +227,8 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
         wb_cache().free_buf(n->m_idx_buf, r_cast< CPContext* >(context));
     }
 
-    btree_status_t on_root_changed(BtreeNodePtr const& new_root, void* context) override {
+    btree_status_t
+    on_root_changed(BtreeNodePtr const &new_root, BtreeNodePtr const &freed_root, void *context) override {
         m_sb->root_node = new_root->node_id();
         m_sb->root_link_version = new_root->link_version();
 
@@ -232,12 +237,18 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
         }
 
         auto& root_buf = static_cast< IndexBtreeNode* >(new_root.get())->m_idx_buf;
-        wb_cache().transact_bufs(ordinal(), m_sb_buffer, root_buf, {}, {}, r_cast< CPContext* >(context));
+        IndexBufferPtrList freed_bufs;
+        if (freed_root) {
+            freed_bufs.push_back(static_cast<IndexBtreeNode *>(freed_root.get())->m_idx_buf);
+        }
+        // Meta is similar to a leftmost child here - it should always be the up buffer for (both) root(s)
+        wb_cache().transact_bufs(ordinal(), nullptr, m_sb_buffer, {root_buf}, freed_bufs,
+                                 r_cast<CPContext *>(context));
         return btree_status_t::success;
     }
 
     btree_status_t repair_links(BtreeNodePtr const& parent_node, void* cp_ctx) {
-        BT_LOG(DEBUG, "Repairing links for parent node {}", parent_node->to_string());
+        BT_LOG(DEBUG, "Repairing links for parent node [{}]", parent_node->to_string());
 
         // Get the last key in the node
         auto const last_parent_key = parent_node->get_last_key< K >();
@@ -247,7 +258,15 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
                           parent_node->node_id());
             return btree_status_t::not_found;
         }
-        BT_LOG(INFO, "Repairing node={} with last_parent_key={}", parent_node->to_string(),
+
+        // Get all current child ids
+        std::set<bnodeid_t> orig_child_ids;
+        for (uint32_t i = 0; i < parent_node->total_entries(); ++i) {
+            BtreeLinkInfo link_info;
+            parent_node->get_nth_value(i, &link_info, true);
+            orig_child_ids.insert(link_info.bnode_id());
+        }
+        BT_LOG(INFO, "Repairing node=[{}] with last_parent_key={}", parent_node->to_string(),
                last_parent_key.to_string());
 
         // Get the first child node and its link info
@@ -272,21 +291,41 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
         auto cur_parent = parent_node;
         BtreeNodeList new_parent_nodes;
         do {
-            if (child_node->has_valid_edge() ||
-                (child_node->is_leaf() && (child_node->next_bnode() == empty_bnodeid))) {
-                BT_DBG_ASSERT(is_parent_edge_node,
-                              "Child node={} is an edge node but parent_node={} is not an edge node",
-                              child_node->node_id(), cur_parent->node_id());
-                cur_parent->set_edge_value(BtreeLinkInfo{child_node->node_id(), child_node->link_version()});
+            if (child_node->has_valid_edge() || (child_node->is_leaf() && child_node->next_bnode() == empty_bnodeid)) {
+                if (child_node->is_node_deleted()) {
+                    // Edge node is merged, we need to set the current last entry as edge
+                    if (cur_parent->total_entries() > 0) {
+                        auto prev_val = V{};
+                        cur_parent->get_nth_value(cur_parent->total_entries() - 1, &prev_val, true);
+                        cur_parent->remove(cur_parent->total_entries() - 1);
+                        cur_parent->set_edge_value(prev_val);
+                        BT_LOG(INFO, "Reparing node={}, child_node=[{}] is deleted, set previous as edge_value={}",
+                               cur_parent->node_id(), child_node->to_string(), prev_val.to_string());
+                    } else {
+                        BT_LOG(INFO, "Found an empty interior node {} with maybe all childs deleted",
+                               cur_parent->node_id());
+                    }
+                } else {
+                    // Update edge and finish
+                    BT_LOG(INFO, "Repairing node={}, child_node=[{}] is an edge node, end loop", cur_parent->node_id(),
+                           child_node->to_string());
+                    child_node->set_next_bnode(empty_bnodeid);
+                    write_node_impl(child_node, cp_ctx);
+                    cur_parent->set_edge_value(BtreeLinkInfo{child_node->node_id(), child_node->link_version()});
+                }
                 break;
             }
 
             auto const child_last_key = child_node->get_last_key< K >();
-            BT_LOG(INFO, "Repairing node={} child_node={} child_last_key={}", cur_parent->node_id(),
+            BT_LOG(INFO, "Repairing node={}, child_node=[{}] child_last_key={}", cur_parent->node_id(),
                    child_node->to_string(), child_last_key.to_string());
 
-            if (child_last_key.compare(last_parent_key) > 0) {
-                // We have reached the last key, we can stop now
+            // There can be cases where the child level merge is successfully persisted but the parent level is not.
+            // In this case, you may have your rightmost child node with last key greater than the last_parent_key. We
+            // have to check the original child ids to see if it's one of the original children.
+            if (!is_parent_edge_node && child_last_key.compare(last_parent_key) > 0
+                && orig_child_ids.find(child_node->node_id()) == orig_child_ids.end()) {
+                // We have reached a child beyond this parent, we can stop now
                 break;
             }
 
@@ -309,20 +348,34 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
             }
 
             // Insert the last key of the child node into parent node
-            cur_parent->insert(cur_parent->total_entries(), child_last_key,
-                               BtreeLinkInfo{child_node->node_id(), child_node->link_version()});
+            if (!child_node->is_node_deleted()) {
+                cur_parent->insert(cur_parent->total_entries(),
+                                   child_node->total_entries() > 0 ? child_last_key : last_parent_key,
+                                   BtreeLinkInfo{child_node->node_id(), child_node->link_version()});
+                if (child_node->total_entries() == 0) {
+                    // There should be at most one empty child node per parent - if we find one, we should stop here
+                    BT_LOG(INFO, "Repairing node={}, child_node=[{}] is empty, end loop", cur_parent->node_id(),
+                           child_node->to_string());
+                    break;
+                }
+            } else {
+                // Node deleted indicates it's freed & no longer used during recovery
+                BT_LOG(INFO, "Repairing node={}, child node=[{}] is deleted, skipping the insert",
+                       cur_parent->node_id(), child_node->to_string());
+            }
 
-            BT_LOG(INFO, "Repairing node={}, repaired so_far={}", cur_parent->node_id(), cur_parent->to_string());
+            BT_LOG(INFO, "Repairing node={}, repaired so_far=[{}]", cur_parent->node_id(), cur_parent->to_string());
 
             // Move to the next child node
-            this->unlock_node(child_node, locktype_t::READ);
             auto const next_node_id = child_node->next_bnode();
+            this->unlock_node(child_node, locktype_t::READ);
             if (next_node_id == empty_bnodeid) {
                 BT_LOG_ASSERT(false,
                               "Child node={} next_node_id is empty, while its not a edge node, parent_node={} "
                               "repair is partial",
                               child_node->node_id(), parent_node->node_id());
                 ret = btree_status_t::not_found;
+                child_node = nullptr;
                 break;
             }
 
@@ -330,10 +383,21 @@ class IndexTable : public IndexTableBase, public Btree< K, V > {
             if (ret != btree_status_t::success) {
                 BT_LOG_ASSERT(false, "Parent node={} repair is partial, because child_node get has failed with ret={}",
                               parent_node->node_id(), enum_name(ret));
+                child_node = nullptr;
                 break;
             }
         } while (true);
-        this->unlock_node(child_node, locktype_t::READ);
+
+        if (child_node) {
+            this->unlock_node(child_node, locktype_t::READ);
+        }
+
+        if (parent_node->total_entries() == 0 && !parent_node->has_valid_edge()) {
+            // We shouldn't have an empty interior node in the tree, let's delete it.
+            // The buf will be released by the caller
+            BT_LOG(INFO, "Parent node={} is empty, deleting it", parent_node->node_id());
+            parent_node->set_node_deleted();
+        }
 
         if (ret == btree_status_t::success) {
             ret = transact_nodes(new_parent_nodes, {}, parent_node, nullptr, cp_ctx);
diff --git a/src/lib/common/crash_simulator.hpp b/src/lib/common/crash_simulator.hpp
index 98c22fe17..cfe8ec327 100644
--- a/src/lib/common/crash_simulator.hpp
+++ b/src/lib/common/crash_simulator.hpp
@@ -13,9 +13,8 @@ class CrashSimulator {
     ~CrashSimulator() = default;
 
     void crash() {
+        m_crashed.update([](auto *s) { *s = true; });
         if (m_restart_cb) {
-            m_crashed.update([](auto* s) { *s = true; });
-
             // We can restart on a new thread to allow other operations to continue
             std::thread t([cb = std::move(m_restart_cb)]() {
                 // Restart could destroy this pointer, so we are storing in local variable and then calling.
diff --git a/src/lib/device/virtual_dev.cpp b/src/lib/device/virtual_dev.cpp
index 3665f13b9..ac49f95dd 100644
--- a/src/lib/device/virtual_dev.cpp
+++ b/src/lib/device/virtual_dev.cpp
@@ -424,6 +424,8 @@ std::error_code VirtualDev::sync_write(const char* buf, uint32_t size, BlkId con
 
     Chunk* chunk;
     uint64_t const dev_offset = to_dev_offset(bid, &chunk);
+    HS_LOG(TRACE, device, "Writing sync in device: {}, offset = {}", chunk->physical_dev_mutable()->pdev_id(),
+           dev_offset);
     if (sisl_unlikely(dev_offset == INVALID_DEV_OFFSET)) {
         return std::make_error_code(std::errc::resource_unavailable_try_again);
     }
@@ -436,6 +438,9 @@ std::error_code VirtualDev::sync_write(const char* buf, uint32_t size, cshared<
     if (hs()->crash_simulator().is_crashed()) { return std::error_code{}; }
 #endif
 
+    HS_LOG(TRACE, device, "Writing sync in device: {}, offset = {}", chunk->physical_dev_mutable()->pdev_id(),
+           chunk->start_offset() + offset_in_chunk);
+
     if (sisl_unlikely(!is_chunk_available(chunk))) {
         return std::make_error_code(std::errc::resource_unavailable_try_again);
     }
@@ -457,6 +462,8 @@ std::error_code VirtualDev::sync_writev(const iovec* iov, int iovcnt, BlkId cons
     auto const size = get_len(iov, iovcnt);
     auto* pdev = chunk->physical_dev_mutable();
 
+    HS_LOG(TRACE, device, "Writing sync in device: {}, offset = {}", pdev->pdev_id(), dev_offset);
+
     COUNTER_INCREMENT(m_metrics, vdev_write_count, 1);
     if (sisl_unlikely(!hs_utils::mod_aligned_sz(dev_offset, pdev->align_size()))) {
         COUNTER_INCREMENT(m_metrics, unalign_writes, 1);
@@ -479,6 +486,8 @@ std::error_code VirtualDev::sync_writev(const iovec* iov, int iovcnt, cshared< C
     auto const size = get_len(iov, iovcnt);
     auto* pdev = chunk->physical_dev_mutable();
 
+    HS_LOG(TRACE, device, "Writing sync in device: {}, offset = {}", pdev->pdev_id(), dev_offset);
+
     COUNTER_INCREMENT(m_metrics, vdev_write_count, 1);
     if (sisl_unlikely(!hs_utils::mod_aligned_sz(dev_offset, pdev->align_size()))) {
         COUNTER_INCREMENT(m_metrics, unalign_writes, 1);
diff --git a/src/lib/homestore.cpp b/src/lib/homestore.cpp
index af2d521c5..b0bd2ff54 100644
--- a/src/lib/homestore.cpp
+++ b/src/lib/homestore.cpp
@@ -321,8 +321,6 @@ void HomeStore::shutdown() {
 #ifdef _PRERELEASE
     flip::Flip::instance().stop_rpc_server();
 #endif
-
-    HomeStore::reset_instance();
     LOGINFO("Homestore is completed its shutdown");
 }
 
diff --git a/src/lib/index/README.md b/src/lib/index/README.md
index db24c9fbb..cb1805e79 100644
--- a/src/lib/index/README.md
+++ b/src/lib/index/README.md
@@ -91,7 +91,14 @@ Merge node happens somewhat similar to split node with respect to the atomicity
 
 Homestore Index service creates 2 more new nodes to replace C30, C40 lets say C30' and C40' respectively and now C20 is linked to C30' and C40' and C30, C40 nodes are deleted.
 
-With this in perspective, dependency graph will link similar to split nodes with new nodes linked to left child, which is linked to parent node.
+We can notice that we have to choose 1 of the 2 node sets, `(C20, C30, C40)` or `(C20, C30', C40')` as the current
+state. **Whether we use the new nodes or the old ones completely depends on the persistence of leftmost child C20.**
+
+With this in perspective, dependency graph will link similar to split nodes with new nodes/freed nodes linked to left
+child, which is linked to parent node.
+
+(NOTE that logically the node release should depend on the leftmost child - but in practice let's do it in a simpler way
+since it would be very unlikely of freed nodes being overwritten in the same cp)
 
 ![Child_Node_Merge](../../../docs/imgs/Child_Node_Merge_1.png)
 
@@ -100,4 +107,4 @@ The journal entries will need to record the existing node deletion information a
 ```
 { <ExistingParentID>, <ExistingChildId>, <NewChildID>, <FreedChildIDs> } 
 {P10, C20, [C30', C40'], [C30, C40]}
-```
\ No newline at end of file
+```
diff --git a/src/lib/index/index_cp.cpp b/src/lib/index/index_cp.cpp
index 955bd523f..a2e6ed72d 100644
--- a/src/lib/index/index_cp.cpp
+++ b/src/lib/index/index_cp.cpp
@@ -249,7 +249,6 @@ void IndexCPContext::process_txn_record(txn_record const* rec, std::map< BlkId,
         }
 
         if (up_buf) {
-            DEBUG_ASSERT(((buf->m_up_buffer == nullptr) || (buf->m_up_buffer == up_buf)), "Inconsistent up buffer");
             auto real_up_buf = (up_buf->m_created_cp_id == cpg->id()) ? up_buf->m_up_buffer : up_buf;
 
 #ifndef NDEBUG
@@ -267,6 +266,20 @@ void IndexCPContext::process_txn_record(txn_record const* rec, std::map< BlkId,
 #endif
 
             if (buf->m_up_buffer != real_up_buf) {
+                if (buf->m_up_buffer) {
+                    buf->m_up_buffer->m_wait_for_down_buffers.decrement(1);
+#ifndef NDEBUG
+                    bool found{false};
+                    for (auto it = buf->m_up_buffer->m_down_buffers.begin(); it != buf->m_up_buffer->m_down_buffers.end(); ++it) {
+                        if (it->lock() == buf) {
+                            buf->m_up_buffer->m_down_buffers.erase(it);
+                            found = true;
+                            break;
+                        }
+                    }
+                    HS_DBG_ASSERT(found, "Down buffer is linked to Up buf, but up_buf doesn't have down_buf in its list");
+#endif
+                }
                 real_up_buf->m_wait_for_down_buffers.increment(1);
                 buf->m_up_buffer = real_up_buf;
             }
diff --git a/src/lib/index/wb_cache.cpp b/src/lib/index/wb_cache.cpp
index 1b7523363..6a20341c6 100644
--- a/src/lib/index/wb_cache.cpp
+++ b/src/lib/index/wb_cache.cpp
@@ -213,12 +213,12 @@ static void set_crash_flips(IndexBufferPtr const& parent_buf, IndexBufferPtr con
                             IndexBufferPtrList const& new_node_bufs, IndexBufferPtrList const& freed_node_bufs) {
     // TODO: Need an API from flip to quickly check if flip is enabled, so this method doesn't check flip_enabled a
     // bunch of times.
-    if (parent_buf && parent_buf->is_meta_buf()) {
+    if (parent_buf == nullptr && child_buf->is_meta_buf()) {
         // Split or merge happening on root
         if (iomgr_flip::instance()->test_flip("crash_flush_on_meta")) {
-            parent_buf->set_crash_flag();
-        } else if (iomgr_flip::instance()->test_flip("crash_flush_on_root")) {
             child_buf->set_crash_flag();
+        } else if (iomgr_flip::instance()->test_flip("crash_flush_on_root")) {
+            new_node_bufs[0]->set_crash_flag();
         }
     } else if ((new_node_bufs.size() == 1) && freed_node_bufs.empty()) {
         // Its a split node situation
@@ -237,6 +237,8 @@ static void set_crash_flips(IndexBufferPtr const& parent_buf, IndexBufferPtr con
             child_buf->set_crash_flag();
         } else if (iomgr_flip::instance()->test_flip("crash_flush_on_merge_at_right_child")) {
             if (!new_node_bufs.empty()) { new_node_bufs[0]->set_crash_flag(); }
+        } else if (iomgr_flip::instance()->test_flip("crash_flush_on_freed_child")) {
+            freed_node_bufs[0]->set_crash_flag();
         }
     } else if (!freed_node_bufs.empty() && (new_node_bufs.size() == freed_node_bufs.size())) {
         // Its a rebalance node situation
@@ -246,6 +248,8 @@ static void set_crash_flips(IndexBufferPtr const& parent_buf, IndexBufferPtr con
             child_buf->set_crash_flag();
         } else if (iomgr_flip::instance()->test_flip("crash_flush_on_rebalance_at_right_child")) {
             if (!new_node_bufs.empty()) { new_node_bufs[0]->set_crash_flag(); }
+        } else if (iomgr_flip::instance()->test_flip("crash_flush_on_freed_child")) {
+            freed_node_bufs[0]->set_crash_flag();
         }
     }
 }
@@ -265,15 +269,8 @@ void IndexWBCache::transact_bufs(uint32_t index_ordinal, IndexBufferPtr const& p
         link_buf(child_buf, buf, true /* is_sibling_link */, cp_ctx);
     }
 
-    for (auto const& buf : freed_node_bufs) {
-        if (!buf->m_wait_for_down_buffers.testz()) {
-            // This buffer has some down bufs depending on it. It can happen for an upper level interior node, where
-            // lower level node (say leaf) has split causing it to write entries in this node, but this node is now
-            // merging with other node, causing it to free. In these rare instances, we link this node to the new
-            // node resulting in waiting for all the down bufs to be flushed before up buf can flush (this buf is
-            // not written anyways)
-            link_buf(child_buf, buf, true /* is_sibling_link */, cp_ctx);
-        }
+    for (auto const &buf: freed_node_bufs) {
+        link_buf(child_buf, buf, true /* is_sibling_link */, cp_ctx);
     }
 
     if (new_node_bufs.empty() && freed_node_bufs.empty()) {
@@ -286,10 +283,9 @@ void IndexWBCache::transact_bufs(uint32_t index_ordinal, IndexBufferPtr const& p
     } else {
         icp_ctx->add_to_txn_journal(index_ordinal,          // Ordinal
                                     child_buf->m_up_buffer, // real up buffer
-                                    new_node_bufs.empty() ? freed_node_bufs[0]->m_up_buffer
-                                                          : new_node_bufs[0]->m_up_buffer, // real in place child
-                                    new_node_bufs,                                         // new node bufs
-                                    freed_node_bufs                                        // free_node_bufs
+                                    child_buf, // real in place child
+                                    new_node_bufs, // new node bufs
+                                    freed_node_bufs // free_node_bufs
         );
     }
 #if 0
@@ -371,6 +367,21 @@ void IndexWBCache::link_buf(IndexBufferPtr const& up_buf, IndexBufferPtr const&
     }
 
     // Now we link the down_buffer to the real up_buffer
+    if (down_buf->m_up_buffer) {
+        // release existing up_buffer's wait count
+        down_buf->m_up_buffer->m_wait_for_down_buffers.decrement();
+#ifndef NDEBUG
+        bool found{false};
+        for (auto it = down_buf->m_up_buffer->m_down_buffers.begin(); it != down_buf->m_up_buffer->m_down_buffers.end(); ++it) {
+            if (it->lock() == down_buf) {
+                down_buf->m_up_buffer->m_down_buffers.erase(it);
+                found = true;
+                break;
+            }
+        }
+        HS_DBG_ASSERT(found, "Down buffer is linked to Up buf, but up_buf doesn't have down_buf in its list");
+#endif
+    }
     real_up_buf->m_wait_for_down_buffers.increment(1);
     down_buf->m_up_buffer = real_up_buf;
 #ifndef NDEBUG
@@ -384,9 +395,13 @@ void IndexWBCache::free_buf(const IndexBufferPtr& buf, CPContext* cp_ctx) {
         bool done = m_cache.remove(buf->m_blkid, node);
         HS_REL_ASSERT_EQ(done, true, "Race on cache removal of btree blkid?");
     }
-
+    buf->m_node_freed = true;
     resource_mgr().inc_free_blk(m_node_size);
-    m_vdev->free_blk(buf->m_blkid, s_cast< VDevCPContext* >(cp_ctx));
+    if (buf->is_clean()) {
+        buf->set_state(index_buf_state_t::DIRTY);
+        r_cast<IndexCPContext *>(cp_ctx)->add_to_dirty_list(buf);
+        resource_mgr().inc_dirty_buf_size(m_node_size);
+    }
 }
 
 //////////////////// Recovery Related section /////////////////////////////////
@@ -418,31 +433,52 @@ void IndexWBCache::recover(sisl::byte_view sb) {
     // This has to be done before doing any repair, because repair can allocate blkids and we don't want to allocate
     // the same blkid which could clash with the blkid next in the buf list.
     //
-    // On the second pass, we only take the new nodes/bufs and then repair their up buffers, if needed.
-    std::vector< IndexBufferPtr > l0_bufs;
+    // On the second pass, we only take part of the parents/siblings and then repair them, if needed.
+    std::vector<IndexBufferPtr> pending_bufs;
+    std::vector<IndexBufferPtr> deleted_bufs;
     for (auto const& [_, buf] : bufs) {
-        if (buf->m_node_freed || (buf->m_created_cp_id == icp_ctx->id())) {
+        if (buf->m_node_freed) {
+            // Freed node
+            if (buf->m_bytes == nullptr) {
+                buf->m_bytes = hs_utils::iobuf_alloc(m_node_size, sisl::buftag::btree_node, m_vdev->align_size());
+                m_vdev->sync_read(r_cast<char *>(buf->m_bytes), m_node_size, buf->blkid());
+            }
+
             if (was_node_committed(buf)) {
-                if (was_node_committed(buf->m_up_buffer)) {
-                    if (buf->m_node_freed) {
-                        // Up buffer was written, so this buffer can be freed and thus can free the blk.
-                        m_vdev->free_blk(buf->m_blkid, s_cast< VDevCPContext* >(icp_ctx));
-                    } else {
-                        m_vdev->commit_blk(buf->m_blkid);
-                    }
-                    l0_bufs.push_back(buf);
-                } else {
-                    buf->m_up_buffer->m_wait_for_down_buffers.decrement();
+                // Mark this buffer as deleted, so that we can avoid using it anymore when repairing its parent's link
+                r_cast<persistent_hdr_t *>(buf->m_bytes)->node_deleted = true;
+                write_buf(nullptr, buf, icp_ctx);
+                deleted_bufs.push_back(buf);
+                pending_bufs.push_back(buf->m_up_buffer);
+            } else {
+                // (Up) buffer is not committed, node need to be kept and (potentially) repaired later
+                buf->m_node_freed = false;
+                buf->m_dirtied_cp_id = BtreeNode::get_modified_cp_id(buf->m_bytes);
+                if (buf->m_created_cp_id == icp_ctx->id()) {
+                    // New nodes need to be commited first
+                    m_vdev->commit_blk(buf->m_blkid);
                 }
+                pending_bufs.push_back(buf);
+                buf->m_wait_for_down_buffers.increment(1); // Purely for recover_buf() counter consistency
+            }
+        } else if (buf->m_created_cp_id == icp_ctx->id()) {
+            // New node
+            if (was_node_committed(buf) && was_node_committed(buf->m_up_buffer)) {
+                // Both current and up buffer is commited, we can safely commit the current block
+                m_vdev->commit_blk(buf->m_blkid);
+                pending_bufs.push_back(buf->m_up_buffer);
+            } else {
+                // Just ignore it
+                buf->m_up_buffer->m_wait_for_down_buffers.decrement();
             }
         }
     }
 
     LOGINFOMOD(wbcache, "Index Recovery detected {} nodes out of {} as new/freed nodes to be recovered in prev cp={}",
-               l0_bufs.size(), bufs.size(), icp_ctx->id());
+                pending_bufs.size(), bufs.size(), icp_ctx->id());
 
-    auto detailed_log = [this](std::map< BlkId, IndexBufferPtr > const& bufs,
-                               std::vector< IndexBufferPtr > const& l0_bufs) {
+    auto detailed_log = [this](std::map<BlkId, IndexBufferPtr> const &bufs,
+                               std::vector<IndexBufferPtr> const &pending_bufs) {
         // Logs to detect down_waits are set correctly for up buffers list of all recovered bufs
         std::string log = fmt::format("\trecovered bufs (#of bufs = {})\n", bufs.size());
         for (auto const& [_, buf] : bufs) {
@@ -450,20 +486,26 @@ void IndexWBCache::recover(sisl::byte_view sb) {
         }
 
         // list of new_bufs
-        fmt::format_to(std::back_inserter(log), "\n\tl0_bufs (#of bufs = {})\n", l0_bufs.size());
-        for (auto const& buf : l0_bufs) {
+        fmt::format_to(std::back_inserter(log), "\n\tpending_bufs (#of bufs = {})\n", pending_bufs.size());
+        for (auto const &buf: pending_bufs) {
             fmt::format_to(std::back_inserter(log), "{}\n", buf->to_string());
         }
         return log;
     };
-    LOGTRACEMOD(wbcache, "All unclean bufs list\n{}", detailed_log(bufs, l0_bufs));
+    LOGTRACEMOD(wbcache, "All unclean bufs list\n{}", detailed_log(bufs, pending_bufs));
+
+    for (auto const &buf: pending_bufs) {
+        recover_buf(buf);
+        if (buf->m_bytes != nullptr && r_cast<persistent_hdr_t *>(buf->m_bytes)->node_deleted) {
+            // This buffer was marked as deleted during repair, so we also need to free it
+            deleted_bufs.push_back(buf);
+        }
+    }
 
-    // Second iteration we start from the lowest levels (which are all new_bufs) and check if up_buffers need to be
-    // repaired. All L1 buffers are not needed to repair, because they are sibling nodes and so we pass false in
-    // do_repair flag.
-    for (auto const& buf : l0_bufs) {
-        recover_buf(buf->m_up_buffer);
+    for (auto const &buf: deleted_bufs) {
+        m_vdev->free_blk(buf->m_blkid, s_cast<VDevCPContext *>(icp_ctx));
     }
+
     m_in_recovery = false;
     m_vdev->recovery_completed();
 }
@@ -556,17 +598,18 @@ folly::Future< bool > IndexWBCache::async_cp_flush(IndexCPContext* cp_ctx) {
 
 void IndexWBCache::do_flush_one_buf(IndexCPContext* cp_ctx, IndexBufferPtr const& buf, bool part_of_batch) {
 #ifdef _PRERELEASE
+    if (hs()->crash_simulator().is_crashed()) {
+        LOGINFOMOD(wbcache, "crash simulation is ongoing, aid simulation by not flushing");
+        return;
+    }
     if (buf->m_crash_flag_on) {
-//        std::string filename = "crash_buf_" + std::to_string(cp_ctx->id()) + ".dot";
-//        LOGINFOMOD(wbcache, "Simulating crash while writing buffer {},  stored in file {}", buf->to_string(), filename);
-//        cp_ctx->to_string_dot(filename);
+        // std::string filename = "crash_buf_" + std::to_string(cp_ctx->id()) + ".dot";
+        // LOGINFOMOD(wbcache, "Simulating crash while writing buffer {},  stored in file {}", buf->to_string(), filename);
+        // cp_ctx->to_string_dot(filename);
         LOGINFOMOD(wbcache, "Simulating crash while writing buffer {}", buf->to_string());
         hs()->crash_simulator().crash();
         cp_ctx->complete(true);
         return;
-    } else if (hs()->crash_simulator().is_crashed()) {
-        LOGINFOMOD(wbcache, "crash simulation is ongoing, aid simulation by not flushing");
-        return;
     }
 #endif
 
@@ -574,17 +617,19 @@ void IndexWBCache::do_flush_one_buf(IndexCPContext* cp_ctx, IndexBufferPtr const
     buf->set_state(index_buf_state_t::FLUSHING);
 
     if (buf->is_meta_buf()) {
-        LOGTRACEMOD(wbcache, "flushing cp {} meta buf {} possibly because of root split", cp_ctx->id(),
+        LOGTRACEMOD(wbcache, "Flushing cp {} meta buf {} possibly because of root split", cp_ctx->id(),
                     buf->to_string());
         auto const& sb = r_cast< MetaIndexBuffer* >(buf.get())->m_sb;
-        meta_service().update_sub_sb(buf->m_bytes, sb.size(), sb.meta_blk());
+        if (!sb.is_empty()) {
+            meta_service().update_sub_sb(buf->m_bytes, sb.size(), sb.meta_blk());
+        }
         process_write_completion(cp_ctx, buf);
     } else if (buf->m_node_freed) {
-        LOGTRACEMOD(wbcache, "Not flushing buf {} as it was freed, its here for merely dependency", cp_ctx->id(),
-                    buf->to_string());
+        LOGTRACEMOD(wbcache, "Not flushing cp {} buf {} as it was freed", cp_ctx->id(), buf->to_string());
+        m_vdev->free_blk(buf->m_blkid, cp_ctx);
         process_write_completion(cp_ctx, buf);
     } else {
-        LOGTRACEMOD(wbcache, "flushing cp {} buf {} info: {}", cp_ctx->id(), buf->to_string(),
+        LOGTRACEMOD(wbcache, "Flushing cp {} buf {} info: {}", cp_ctx->id(), buf->to_string(),
                     BtreeNode::to_string_buf(buf->raw_buffer()));
         m_vdev->async_write(r_cast< const char* >(buf->raw_buffer()), m_node_size, buf->m_blkid, part_of_batch)
             .thenValue([buf, cp_ctx](auto) {
@@ -685,7 +730,7 @@ void IndexWBCache::get_next_bufs_internal(IndexCPContext* cp_ctx, uint32_t max_c
         std::optional< IndexBufferPtr > buf = cp_ctx->next_dirty();
         if (!buf) { break; } // End of list
 
-        if ((*buf)->m_wait_for_down_buffers.testz()) {
+        if ((*buf)->state() == index_buf_state_t::DIRTY && (*buf)->m_wait_for_down_buffers.testz()) {
             bufs.emplace_back(std::move(*buf));
             ++count;
         } else {
diff --git a/src/tests/test_common/homestore_test_common.hpp b/src/tests/test_common/homestore_test_common.hpp
index 174039495..b01aff3f2 100644
--- a/src/tests/test_common/homestore_test_common.hpp
+++ b/src/tests/test_common/homestore_test_common.hpp
@@ -198,8 +198,8 @@ class HSTestHelper {
         }
 
         homestore::HomeStore::instance()->shutdown();
+        iomanager.stop(); // Stop iomanager first in case any fiber is still referencing homestore resources
         homestore::HomeStore::reset_instance();
-        iomanager.stop();
 
         if (cleanup) {
             remove_files(m_generated_devs);
@@ -251,6 +251,11 @@ class HSTestHelper {
         m_fc.inject_delay_flip(flip_name, {null_cond}, freq, delay_usec);
         LOGDEBUG("Flip {} set", flip_name);
     }
+
+    void remove_flip(const std::string flip_name) {
+        m_fc.remove_flip(flip_name);
+        LOGDEBUG("Flip {} removed", flip_name);
+    }
 #endif
 
     static void fill_data_buf(uint8_t* buf, uint64_t size, uint64_t pattern = 0) {
diff --git a/src/tests/test_index_crash_recovery.cpp b/src/tests/test_index_crash_recovery.cpp
index 11235be6a..9f447e7c4 100644
--- a/src/tests/test_index_crash_recovery.cpp
+++ b/src/tests/test_index_crash_recovery.cpp
@@ -36,23 +36,25 @@ SISL_LOGGING_DECL(test_index_crash_recovery)
 
 SISL_OPTION_GROUP(test_index_crash_recovery,
                   (num_iters, "", "num_iters", "number of iterations for rand ops",
-                   ::cxxopts::value< uint32_t >()->default_value("500"), "number"),
+                      ::cxxopts::value< uint32_t >()->default_value("500"), "number"),
                   (num_entries, "", "num_entries", "number of entries to test with",
-                   ::cxxopts::value< uint32_t >()->default_value("5000"), "number"),
+                      ::cxxopts::value< uint32_t >()->default_value("5000"), "number"),
                   (run_time, "", "run_time", "run time for io", ::cxxopts::value< uint32_t >()->default_value("360000"),
-                   "seconds"),
+                      "seconds"),
                   (max_keys_in_node, "", "max_keys_in_node", "max_keys_in_node",
-                   ::cxxopts::value< uint32_t >()->default_value("0"), ""),
+                      ::cxxopts::value< uint32_t >()->default_value("20"), ""),
+                  (min_keys_in_node, "", "min_keys_in_node", "min_keys_in_node",
+                      ::cxxopts::value< uint32_t >()->default_value("6"), ""),
                   (operation_list, "", "operation_list",
-                   "operation list instead of default created following by percentage",
-                   ::cxxopts::value< std::vector< std::string > >(), "operations [...]"),
+                      "operation list instead of default created following by percentage",
+                      ::cxxopts::value< std::vector< std::string > >(), "operations [...]"),
                   (preload_size, "", "preload_size", "number of entries to preload tree with",
-                   ::cxxopts::value< uint32_t >()->default_value("1000"), "number"),
+                      ::cxxopts::value< uint32_t >()->default_value("1000"), "number"),
                   (init_device, "", "init_device", "init device", ::cxxopts::value< bool >()->default_value("1"), ""),
                   (cleanup_after_shutdown, "", "cleanup_after_shutdown", "cleanup after shutdown",
-                   ::cxxopts::value< bool >()->default_value("1"), ""),
+                      ::cxxopts::value< bool >()->default_value("1"), ""),
                   (seed, "", "seed", "random engine seed, use random if not defined",
-                   ::cxxopts::value< uint64_t >()->default_value("0"), "number"))
+                      ::cxxopts::value< uint64_t >()->default_value("0"), "number"))
 
 void log_obj_life_counter() {
     std::string str;
@@ -96,10 +98,16 @@ class SequenceGenerator {
         keyDist_ = std::uniform_int_distribution<>(start_range_, end_range_);
     }
 
+    void fillRange(uint64_t start, uint64_t end) {
+        for (uint64_t i = start; i <= end; ++i) {
+            keyStates[i] = true;
+        }
+    }
+
     OperationList generateOperations(size_t numOperations, bool reset = false) {
         std::vector< Operation > operations;
         if (reset) { this->reset(); }
-        for (size_t i = 0; i < numOperations; ++i) {
+        while (operations.size() < numOperations) {
             uint32_t key = keyDist_(gen_);
             auto [it, inserted] = keyStates.try_emplace(key, false);
             auto& inUse = it->second;
@@ -117,6 +125,7 @@ class SequenceGenerator {
 
         return operations;
     }
+
     __attribute__((noinline)) std::string showKeyState(uint64_t key) const {
         auto it = keyStates.find(key);
         if (it != keyStates.end()) { return it->second ? "Put" : "Remove"; }
@@ -131,6 +140,7 @@ class SequenceGenerator {
         }
         return occurrences;
     }
+
     __attribute__((noinline)) std::string printOperations(const OperationList& operations) const {
         std::ostringstream oss;
         for (const auto& [key, opType] : operations) {
@@ -139,6 +149,7 @@ class SequenceGenerator {
         }
         return oss.str();
     }
+
     __attribute__((noinline)) std::string printKeysOccurrences(const OperationList& operations) const {
         std::set< uint64_t > keys = collectUniqueKeys(operations);
         std::ostringstream oss;
@@ -152,6 +163,7 @@ class SequenceGenerator {
         }
         return oss.str();
     }
+
     __attribute__((noinline)) std::string printKeyOccurrences(const OperationList& operations, uint64_t key ) const {
         std::ostringstream oss;
         auto keyOccurrences = inspect(operations, key);
@@ -162,6 +174,7 @@ class SequenceGenerator {
         }
         return oss.str();
     }
+
     void reset() { keyStates.clear(); }
 
 private:
@@ -204,6 +217,7 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
             m_test->m_cfg.m_leaf_node_type = T::leaf_node_type;
             m_test->m_cfg.m_int_node_type = T::interior_node_type;
             m_test->m_cfg.m_max_keys_in_node = SISL_OPTIONS["max_keys_in_node"].as< uint32_t >();
+            m_test->m_cfg.m_min_keys_in_node = SISL_OPTIONS["min_keys_in_node"].as<uint32_t>();
             m_test->m_bt = std::make_shared< typename T::BtreeType >(std::move(sb), m_test->m_cfg);
             return m_test->m_bt;
         }
@@ -232,6 +246,7 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
         LOGINFO("Node size {} ", hs()->index_service().node_size());
         this->m_cfg = BtreeConfig(hs()->index_service().node_size());
         this->m_cfg.m_max_keys_in_node = SISL_OPTIONS["max_keys_in_node"].as< uint32_t >();
+        this->m_cfg.m_min_keys_in_node = SISL_OPTIONS["min_keys_in_node"].as<uint32_t>();
         auto uuid = boost::uuids::random_generator()();
         auto parent_uuid = boost::uuids::random_generator()();
 
@@ -257,7 +272,10 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
     }
 
     void reset_btree() {
+        hs()->index_service().remove_index_table(this->m_bt);
         this->m_bt->destroy();
+        this->trigger_cp(true);
+
         auto uuid = boost::uuids::random_generator()();
         auto parent_uuid = boost::uuids::random_generator()();
         this->m_bt = std::make_shared< typename T::BtreeType >(uuid, parent_uuid, 0, this->m_cfg);
@@ -274,7 +292,7 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
     void reapply_after_crash() {
         ShadowMap< K, V > snapshot_map{this->m_shadow_map.max_keys()};
         snapshot_map.load(m_shadow_filename);
-        LOGDEBUG("\tSnapshot before crash\n{}", snapshot_map.to_string());
+        // LOGDEBUG("\tSnapshot before crash\n{}", snapshot_map.to_string());
         auto diff = this->m_shadow_map.diff(snapshot_map);
 
         // visualize tree after crash
@@ -286,16 +304,23 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
         for (const auto& [k, addition] : diff) {
             dif_str += fmt::format(" {} \t{}\n", k.key(), addition);
         }
-        LOGDEBUG("Diff between shadow map and snapshot map\n{}\n", dif_str);
+        // LOGDEBUG("Diff between shadow map and snapshot map\n{}\n", dif_str);
 
-        for (const auto& [k, addition] : diff) {
+        for (const auto &[k, addition]: diff) {
             // this->print_keys(fmt::format("reapply: before inserting key {}", k.key()));
             //  this->visualize_keys(recovered_tree_filename);
-            if (addition) { this->force_upsert(k.key()); }
+            if (addition) {
+                LOGDEBUG("Reapply: Inserting key {}", k.key());
+                this->force_upsert(k.key());
+            } else {
+                LOGDEBUG("Reapply: Removing key {}", k.key());
+                this->remove_one(k.key(), false);
+            }
         }
-        test_common::HSTestHelper::trigger_cp(true);
+        trigger_cp(true);
         this->m_shadow_map.save(m_shadow_filename);
     }
+
     void reapply_after_crash(OperationList& operations) {
         for (const auto& [key, opType] : operations) {
             switch (opType) {
@@ -309,7 +334,7 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
                 break;
             }
         }
-        test_common::HSTestHelper::trigger_cp(true);
+        trigger_cp(true);
     }
 
     void TearDown() override {
@@ -331,14 +356,15 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
     }
 
     void crash_and_recover(uint32_t s_key, uint32_t e_key) {
-        this->print_keys("Btree prior to CP and susbsequent simulated crash: ");
-        test_common::HSTestHelper::trigger_cp(false);
+        // this->print_keys("Btree prior to CP and susbsequent simulated crash: ");
+        trigger_cp(false);
         this->wait_for_crash_recovery();
         // this->visualize_keys("tree_after_crash_" + std::to_string(s_key) + "_" + std::to_string(e_key) + ".dot");
 
-        this->print_keys("Post crash and recovery, btree structure: ");
+        // this->print_keys("Post crash and recovery, btree structure: ");
         this->reapply_after_crash();
 
+        // Verification
         this->get_all();
         LOGINFO("Expect to have [{},{}) in tree and it is actually{} ", s_key, e_key, tree_key_count());
         ASSERT_EQ(this->m_shadow_map.size(), this->m_bt->count_keys(this->m_bt->root_node_id()))
@@ -346,10 +372,10 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
     }
 
     void crash_and_recover(OperationList& operations, std::string filename = "") {
-        //        this->print_keys("Btree prior to CP and susbsequent simulated crash: ");
-        test_common::HSTestHelper::trigger_cp(false);
+        // this->print_keys("Btree prior to CP and susbsequent simulated crash: ");
+        trigger_cp(false);
         this->wait_for_crash_recovery();
-        //        this->print_keys("Post crash and recovery, btree structure:");
+        // this->print_keys("Post crash and recovery, btree structure:");
 
         if (!filename.empty()) {
             LOGINFO("Visualize the tree file {}", filename);
@@ -364,6 +390,7 @@ struct IndexCrashTest : public test_common::HSTestHelper, BtreeTestHelper< TestT
             this->visualize_keys("after_reapply__" + filename);
         }
 
+        // Verification
         this->get_all();
     }
 
@@ -442,82 +469,6 @@ TYPED_TEST(IndexCrashTest, SplitOnLeftEdge) {
     this->query_all_paginate(80);
 }
 
-/*
-TYPED_TEST(IndexCrashTest, ManualMergeCrash){
-    // Define the lambda function
-    const uint32_t num_entries = 30;
-
-    auto initTree = [this, num_entries]() {
-        for (uint64_t k = 0u; k < num_entries; ++k) {
-            this->force_upsert(k);
-        }
-        test_common::HSTestHelper::trigger_cp(true);
-        this->m_shadow_map.save(this->m_shadow_filename);
-    };
-
-    std::vector< OperationList > removing_scenarios = {
-        {{29, OperationType::Remove},
-         {28, OperationType::Remove},
-         {27, OperationType::Remove},
-         {26, OperationType::Remove},
-         {25, OperationType::Remove},
-         {24, OperationType::Remove}}
-    };
-
-    auto scenario = removing_scenarios[0];
-
-    LOGINFO("Step 1-1: Populate some keys and flush");
-    initTree();
-    this->visualize_keys("tree_init.dot");
-    LOGINFO("Step 2-1: Set crash flag, remove some keys in reverse order");
-    this->set_basic_flip("crash_flush_on_merge_at_parent");
-
-    for (auto [k, _] : scenario) {
-        LOGINFO("\n\n\t\t\t\t\t\t\t\t\t\t\t\t\tRemoving entry {}", k);
-        this->remove_one(k);
-    }
-    this->visualize_keys("tree_before_crash.dot");
-
-    LOGINFO("Step 3-1: Trigger cp to crash");
-    this->crash_and_recover(scenario, "recover_tree_crash_1.dot");
-    test_common::HSTestHelper::trigger_cp(true);
-    this->get_all();
-
-    LOGINFO("Step 1-2: Populate some keys and flush");
-    initTree();
-    this->visualize_keys("tree_init_02.dot");
-    LOGINFO("Step 2-2: Set crash flag, remove some keys in reverse order");
-    this->set_basic_flip("crash_flush_on_merge_at_left_child");
-    for (auto [k, _] : scenario) {
-        LOGINFO("\n\n\t\t\t\t\t\t\t\t\t\t\t\t\tRemoving entry {}", k);
-        this->remove_one(k);
-    }
-    this->visualize_keys("tree_before_crash_2.dot");
-
-    LOGINFO("Step 3-2: Trigger cp to crash");
-    this->crash_and_recover(scenario, "recover_tree_crash_2.dot");
-    test_common::HSTestHelper::trigger_cp(true);
-    this->get_all();
-
-    LOGINFO("Step 1-3: Populate some keys and flush");
-    initTree();
-    this->visualize_keys("tree_init_03.dot");
-    LOGINFO("Step 2-3: Set crash flag, remove some keys in reverse order");
-    this->set_basic_flip("crash_flush_on_freed_child");
-    for (auto [k, _] : scenario) {
-        LOGINFO("\n\n\t\t\t\t\t\t\t\t\t\t\t\t\tRemoving entry {}", k);
-        this->remove_one(k);
-    }
-    LOGINFO("Step 2-3: Set crash flag, remove some keys in reverse order");
-    this->visualize_keys("tree_before_crash_3.dot");
-
-    LOGINFO("Step 3-3: Trigger cp to crash");
-    this->crash_and_recover(scenario, "recover_tree_crash_3.dot");
-    test_common::HSTestHelper::trigger_cp(true);
-    this->get_all();
-}
-*/
-
 TYPED_TEST(IndexCrashTest, SplitCrash1) {
     // Define the lambda function
     auto const num_entries = SISL_OPTIONS["num_entries"].as< uint32_t >();
@@ -583,6 +534,215 @@ TYPED_TEST(IndexCrashTest, long_running_put_crash) {
 
     }
 }
+
+// Basic reverse and forward order remove with different flip points
+TYPED_TEST(IndexCrashTest, MergeRemoveBasic) {
+    vector<std::string> flip_points = {
+        "crash_flush_on_merge_at_parent",
+        "crash_flush_on_merge_at_left_child",
+        "crash_flush_on_freed_child",
+    };
+
+    for (size_t i = 0; i < flip_points.size(); ++i) {
+        this->reset_btree();
+
+        auto &flip_point = flip_points[i];
+        LOGINFO("=== Testing flip point: {} - {} ===", i + 1, flip_point);
+
+        // Populate some keys [1,num_entries) and trigger cp to persist
+        LOGINFO("Step {}-1: Populate some keys and flush", i+1);
+        auto const num_entries = SISL_OPTIONS["num_entries"].as< uint32_t >();
+        for (auto k = 0u; k < num_entries; ++k) {
+            this->put(k, btree_put_type::INSERT, true /* expect_success */);
+        }
+        test_common::HSTestHelper::trigger_cp(true);
+        this->m_shadow_map.save(this->m_shadow_filename);
+
+        this->visualize_keys("tree_merge_full.dot");
+
+        // Split keys into batches and remove the last one in reverse order
+        LOGINFO("Step {}-2: Set crash flag, remove some keys in reverse order", i + 1);
+        int batch_num = 4;
+        {
+            int n = batch_num;
+            auto r = num_entries * n / batch_num - 1;
+            auto l = num_entries * (n - 1) / batch_num;
+            OperationList ops;
+            for (auto k = r; k >= l; --k) {
+                ops.emplace_back(k, OperationType::Remove);
+            }
+            LOGINFO("Step {}-2-1: Remove keys in batch {}/{} ({} to {})", i + 1, n, batch_num, r, l);
+
+            this->set_basic_flip(flip_point);
+            for (auto k = r; k >= l; --k) {
+                LOGINFO("Removing key {}", k);
+                this->remove_one(k);
+            }
+            this->visualize_keys("tree_merge_before_first_crash.dot");
+
+            LOGINFO("Step {}-2-2: Trigger cp to crash", i + 1);
+            this->crash_and_recover(ops);
+        }
+
+        // Remove the next batch of keys in forward order
+        LOGINFO("Step {}-3: Remove another batch in ascending order", i + 1) {
+            int n = batch_num - 1;
+            auto r = num_entries * n / batch_num - 1;
+            auto l = num_entries * (n - 1) / batch_num;
+            OperationList ops;
+            for (auto k = l; k <= r; ++k) {
+                ops.emplace_back(k, OperationType::Remove);
+            }
+            LOGINFO("Step {}-3-1: Remove keys in batch {}/{} ({} to {})", i + 1, n, batch_num, l, r);
+
+            this->set_basic_flip(flip_point);
+            for (auto k = l; k <= r; ++k) {
+                LOGINFO("Removing key {}", k);
+                this->remove_one(k);
+            }
+            this->visualize_keys("tree_merge_before_second_crash.dot");
+
+            LOGINFO("Step {}-3-2: Trigger cp to crash", i + 1);
+            this->crash_and_recover(ops);
+        }
+
+        LOGINFO("Step {}-4: Cleanup the tree", i + 1);
+        for (auto k = 0u; k < num_entries; ++k) {
+            this->remove_one(k, false);
+        }
+        test_common::HSTestHelper::trigger_cp(true);
+        this->get_all();
+    }
+}
+//
+// TYPED_TEST(IndexCrashTest, MergeCrash1) {
+//     auto const num_entries = SISL_OPTIONS["num_entries"].as<uint32_t>();
+//     vector<std::string> flips = {
+//         "crash_flush_on_merge_at_parent", "crash_flush_on_merge_at_left_child", "crash_flush_on_freed_child"
+//     };
+//     SequenceGenerator generator(0 /*putFreq*/, 100 /* removeFreq*/, 0 /*start_range*/, num_entries - 1 /*end_range*/);
+//     OperationList operations;
+//     for (size_t i = 0; i < flips.size(); ++i) {
+//         this->reset_btree();
+//         LOGINFO("Step {}-1: Init btree", i + 1);
+//         for (auto k = 0u; k < num_entries; ++k) {
+//             this->put(k, btree_put_type::INSERT, true /* expect_success */);
+//         }
+//         test_common::HSTestHelper::trigger_cp(true);
+//         this->print_keys("Inited tree");
+//
+//         LOGINFO("Step {}-2: Set flag {}", i + 1, flips[i]);
+//         this->set_basic_flip(flips[i], 1, 10);
+//         generator.reset();
+//         generator.fillRange(0, num_entries - 1);
+//
+//         // Randomly remove some keys
+//         std::random_device rd; // Random device to seed the generator
+//         std::mt19937 gen(rd()); // Mersenne Twister engine
+//         std::uniform_int_distribution<> dis(num_entries / 4, num_entries / 2);
+//         auto num_keys_to_remove = dis(gen);
+//         LOGINFO("Removing {} keys before crash", num_keys_to_remove);
+//         operations = generator.generateOperations(num_keys_to_remove, false /* reset */);
+//         for (auto [k, _]: operations) {
+//             LOGINFO("Removing key {}", k);
+//             this->remove_one(k, true);
+//         }
+//
+//         LOGINFO("Step {}-3: Simulate crash and recover", i + 1);
+//         this->crash_and_recover(operations, fmt::format("recover_tree_crash_{}.dot", i + 1));
+//     }
+// }
+//
+// TYPED_TEST(IndexCrashTest, MergeManualCrash) {
+//     std::vector<std::string> flip_points = {
+//         "crash_flush_on_merge_at_parent",
+//         "crash_flush_on_merge_at_left_child",
+//         "crash_flush_on_freed_child",
+//     };
+//
+//     constexpr uint32_t num_entries = 28; // with max=5 & min=3
+//
+//     auto initTree = [this, num_entries]() {
+//         for (auto k = 0u; k < num_entries; ++k) {
+//             this->put(k, btree_put_type::INSERT, true /* expect_success */);
+//         }
+//         test_common::HSTestHelper::trigger_cp(true);
+//         this->m_shadow_map.save(this->m_shadow_filename);
+//     };
+//
+//     std::vector<OperationList> removing_scenarios = {
+//         {
+//             {27, OperationType::Remove},
+//             {26, OperationType::Remove},
+//             {25, OperationType::Remove},
+//             {24, OperationType::Remove},
+//             {23, OperationType::Remove},
+//             {22, OperationType::Remove},
+//         }, // Merge 2 rightmost leaf nodes in 1 action
+//         {
+//             {27, OperationType::Remove},
+//             {26, OperationType::Remove},
+//             {25, OperationType::Remove},
+//             {24, OperationType::Remove},
+//             {23, OperationType::Remove},
+//             {20, OperationType::Remove},
+//             {19, OperationType::Remove},
+//         }, // Merge 3 rightmost leaf nodes in 1 action
+//         {
+//             {27, OperationType::Remove},
+//             {26, OperationType::Remove},
+//             {25, OperationType::Remove},
+//             {24, OperationType::Remove},
+//             {23, OperationType::Remove},
+//             {22, OperationType::Remove},
+//             {21, OperationType::Remove},
+//             {20, OperationType::Remove},
+//             {19, OperationType::Remove},
+//         }, // Merge 3 rightmost leaf nodes in 2 actions
+//         {
+//             {23, OperationType::Remove},
+//             {22, OperationType::Remove},
+//             {11, OperationType::Remove},
+//             {10, OperationType::Remove},
+//             {13, OperationType::Remove},
+//         }, // Merge from level=0 then level=1
+//         // {
+//         //     {16, OperationType::Remove},
+//         // }, // Merge from level=1 then level=0 - need to set min=4
+//     };
+//
+//     for (int i = 0; i < static_cast<int>(removing_scenarios.size()); i++) {
+//         auto scenario = removing_scenarios[i];
+//         auto s_idx = i + 1;
+//         LOGINFO("\n\tTesting scenario {}", s_idx);
+//         for (int j = 0; j < static_cast<int>(flip_points.size()); j++) {
+//             const auto &flip_point = flip_points[j];
+//             auto f_idx = j + 1;
+//             LOGINFO("\n\t\t\t\tTesting flip point: {}", flip_point);
+//
+//             LOGINFO("Step {}-{}-1: Populate keys and flush", s_idx, f_idx);
+//             initTree();
+//             this->visualize_keys(fmt::format("tree_init.{}_{}.dot", s_idx, f_idx));
+//
+//             LOGINFO("Step {}-{}-2: Set crash flag, remove keys in reverse order", s_idx, f_idx);
+//             this->set_basic_flip(flip_point);
+//             for (auto k: scenario) {
+//                 LOGINFO("Removing entry {}", k.first);
+//                 this->remove_one(k.first);
+//             }
+//             this->visualize_keys(fmt::format("tree_before_first_crash.{}_{}.dot", s_idx, f_idx));
+//             this->remove_flip(flip_point);
+//
+//             LOGINFO("Step {}-{}-3: Trigger cp to crash", s_idx, f_idx);
+//             this->crash_and_recover(scenario);
+//             test_common::HSTestHelper::trigger_cp(true);
+//             this->get_all();
+//
+//             this->reset_btree();
+//             test_common::HSTestHelper::trigger_cp(true);
+//         }
+//     }
+// }
 #endif
 
 int main(int argc, char* argv[]) {