Virtual Machine Full Sync Loop Due to Backup Snapshots in VMware Live Recovery

Products

• VMware Live Recovery

Issue/Introduction

 This article addresses virtual machines that remain stuck in an infinite "Full Synchronization" loop. This behavior is typically observed in environments where third-party backup software performs snapshot consolidations that interrupt the replication initialization process.

Environment

• Product: VMware Live Recovery (VLR)
• Version: All versions 9.x
• Platform: vSphere 8.x
• Dependency: Third-party backup software (e.g., Veeam) utilizing snapshot consolidation.

Cause

A race condition occurs between the VMware Live Recovery (VLSR) initial synchronization and the snapshot consolidation phase of third-party backup software. When the backup snapshot is removed, a DISK_ATTACHED event is generated. This event forces the replication filter (LWD) to reinitialize, which causes the initial synchronization to restart from 0%.

Resolution

1. Identify the virtual machines currently trapped in the synchronization cycle.
2. Pause the incremental backup schedules for the affected virtual machines within your third-party backup software.
3. Monitor the VLSR status in the vSphere Client and allow the initial synchronization to reach 100% completion ("OK").
4. Resume the backup schedules only after the system has successfully transitioned to incremental/delta mode.