V1 and V2 Volume Feature Support
This page summarizes the expected behavior differences between V1 and V2 volumes and provides a feature support matrix for the Longhorn v1.12.0 documentation set.
Expected Behavioral Differences
Snapshot Deletion Behavior
When deleting the snapshot that is the direct parent of volume-head, V1 and V2 volumes behave differently.
| Behavior | V1 Volume | V2 Volume |
|---|---|---|
| Snapshot list result | The snapshot remains in the list and is marked as removed. | The snapshot is deleted immediately and disappears from the list. |
| Snapshot CR behavior | The Snapshot CR remains and reflects the removed state. | The Snapshot CR is removed immediately. |
| Reason | The latest snapshot cannot be coalesced into the live volume-head immediately, so cleanup is deferred until a later purge opportunity. | The V2 data engine supports live merging of the parent snapshot into volume-head, so cleanup can finish immediately. |
| Cleanup timing | Cleanup happens later, typically after another snapshot is created and purge can proceed. | Cleanup completes as part of the delete operation. |
Snapshot Purge Behavior
Snapshot purge behavior also differs between V1 and V2 volumes.
In V1, purge is the operation that coalesces snapshots previously marked as removed. It runs separately from snapshot deletion and is subject to a per-node concurrency limit (Snapshot Heavy Task Concurrent Limit). As a result, removed snapshots may remain visible in the snapshot chain or API response until purge completes.
In V2, purge runs immediately and removes eligible system-created snapshots (those not created by the user) from the replica chain in one operation. The underlying storage layer performs the merge during the purge.
Feature Support Matrix
| Feature | V1 | V2 | Support Notes |
|---|---|---|---|
| Data Protection | |||
| Snapshot | ✔️ | ✔️ | - |
| Backup and Restore | ✔️ | ✔️ | - |
| DR Volume | ✔️ | ✔️ | - |
| System Backup and Restore | ✔️ | ✔️ | - |
| Snapshot Data Integrity Check | ✔️ | ✔️ | - |
| RWX Volume | |||
| Creation and Deletion | ✔️ | ✔️ | - |
| Encryption | ✔️ | ✔️ | - |
| Migratable RWX Volume | ✔️ | ✔️ | - |
| Volume Operations | |||
| Volume Expansion | ✔️ | ✔️ | - |
| Volume Cloning | ✔️ | ✔️ | - |
| Fast Volume Cloning | Not planned | ✔️ | - |
| Volume Encryption | ✔️ | ✔️ | - |
| Filesystem Trim | ✔️ | ✔️ | - |
| Replica Scheduling | |||
| Replica Scheduling | ✔️ | ✔️ | - |
| High Availability | |||
| Data Locality: disabled and best-effort | ✔️ | ✔️ | - |
| Data Locality: strict local | ✔️ | Not supported | TBD |
| Auto Balance Replicas | ✔️ | ✔️ | - |
| Recurring Jobs | |||
| Recurring Job | ✔️ | ✔️ | - |
| Replica Rebuilding | |||
| Online Full Rebuilding | ✔️ | ✔️ | - |
| Online Delta Rebuilding | ✔️ | ✔️ | - |
| Online Fast Rebuilding | ✔️ | ✔️ | - |
| Offline Full Rebuilding | ✔️ | ✔️ | - |
| Offline Delta Rebuilding | ✔️ | ✔️ | - |
| Offline Fast Rebuilding | ✔️ | Not supported | TBD |
| QoS | Not supported | ✔️ | - |
| Backing Image | |||
| Creation and Deletion | ✔️ | Not supported | Replaced by Containerized Data Importer (CDI) in V2 |
| Encryption | ✔️ | Not supported | Replaced by Containerized Data Importer (CDI) in V2 |
| Backup | ✔️ | Not supported | Replaced by Containerized Data Importer (CDI) in V2 |
| Networking | |||
| Storage Network | ✔️ | ✔️ | - |
| IPv4 | ✔️ | ✔️ | - |
| IPv6 | ✔️ | ✔️ | - |
| Orphan Resource | |||
| Orphaned Replica Data Management | ✔️ | ✔️ | - |
| Orphaned Instance Management | ✔️ | Not supported | - |
| Volume Live Migration | |||
| Volume Live Migration | ✔️ | ✔️ | - |
| Engine Live Upgrade | |||
| Engine Live Upgrade | ✔️ | Not supported | Supported when upgrading from v1.12.x to v1.13.x |
| Storage Sharding | |||
| Storage Sharding | Not planned | ✔️ | Experimental Feature for V2 |
© 2019-2026 Longhorn a Series of LF Projects, LLC. Documentation Distributed under CC-BY-4.0.
For website terms of use, trademark policy and other project policies please see lfprojects.org/policies.
