Virtual Machine Snapshot fails with error "VMX file size is too big" - VMware Live Cyber Recovery

Products

• VMware Live Recovery

Issue/Introduction

Symptoms

• Following error may be seen in the VLCR UI
  
  Error Severity Warning : Target vmname:  Description Failed to backup VM 'VM Name' (/UUID/VM Name.vmx) during stage: finishing backup, for task: drc-UUID. VM VM Name snapshot failed. Internal error: VMX file size is too big. Please contact support.
  
  Or 
  
  Description Failed to backup VM 'VM Name' (/VM Name/VM Name.vmx) during stage: performing backup, for task: drc-########-####-####-####-########45f9. VM bisecpdbm snapshot failed. Internal error: VMX file size is 55370 bytes which exceeds the max supported small file size 53320 bytes. Please contact support.
  
  
• The following signature will be recorded under the : /da/data/var/log/drcMgr-svc.log 
  
  [SnappleServer.DRCTasks:0] [DRC] [drc-UUID] Task drc-mgr-UUID is started for VM[/UUID/VM Name.vmx] for task [SnappleServer.DRCTasks:0] [DRC] Task drc-mgr-UUID failed: Error VM_BACKUP_FAILED (6900): Failed to backup VM '[WorkloadDatastore] UUID/<VM name.vmx>' (VM Name): VM <VM Name> snapshot failed. Internal error: VMX file size is too big. Please contact support. (Created at DRCAgentSvc.java:5147) [SnappleServer.DRCTasks:0] __ERR__ [DRC] [drc-UUID] Backup task drc-mgr-UUID failed.


• Manual snapshot succeeds on the same VM from either vCenter or ESXi host.

Environment

VMware Live Cyber Recovery 9.0.0.11

 

Cause

The failure is due to a larger VMX file size caused by guestInfo.appInfo information from the appInfo plugin. This is an application tool that is dumping alot of info into the VMX file. VLCR has a  hard 55K limits on the VMX file size due to the way they are stored on the underlying filesystem.

Resolution

1. Schedule a maintenance window for the VM and disable appinfo plugin via VMware tools configuration file at the VM level.
   
   
2. To disable appInfo plugin, login to the guest with admin credentials.
   
   
   • Linux Guest OS
     

   • vmware-toolbox-cmd config set appInfo disabled true

     OR

   • vmware-toolbox-cmd config set appinfo poll-interval 0

   • Windows Guest OS
     

   • VMwareToolboxCmd.exe config set appInfo disabled true
     
     OR

   • VMwareToolboxCmd.exe config set appInfo poll-interval 0

3. After disabling the appInfo plugin, please shutdown and power-on the virtual machine to remove the data from .vmx file. 

Note: Guest restart or reboot will not remove the data from .vmx

 

For additional information about appInfo plugin refer VMware tools documentation

Additional Information

Caveats for High-frequency Snapshots