vSAN ObjectScrubsPerYear advanced configuration alert in Skyline Health

Products

• VMware vSAN

Issue/Introduction

Skyline Health check flags an alert for "Advanced vSAN Configuration in sync" regarding parameter vSAN.ObjectScrubsPerYear being set to 1.

Environment

vSAN 7.0 Update 1 and above.

Cause

vSAN ObjectScrubsPerYear is an advanced configuration setting, and is set to 0 by default - which means that idle objects are scrubbed regularly.

In vSAN 7.0 U1, when the change to scrub more frequently was implemented, a condition was discovered which could sometimes lead to LSOM memory congestion. To work around this problem, some temporary configuration changes were implemented, which included setting vSAN/ObjectScrubsPerYear to 1.

From vSAN 7.0 Update 2 onwards, the potential for a vSAN node to trigger the above condition has been addressed, and the parameter vSAN/ObjectScrubsPerYear has been reset to the default value of 0.

 

If this parameter is found to be set to 1 on an environment running vSAN 7.0 Update 2 or later, this is likely a carryover from when the above workaround was implemented on a previous release. The recommended setting for this parameter on vSAN 7.0 Update 2 and later is 0.

 

Resolution

If running vSAN 7.0 Update 2 or later, set the vSAN ObjectScrubsPerYear parameter to 0 on an SSH session for any ESXi hosts where it is not already 0.

 

esxcfg-advcfg -s 0 /VSAN/ObjectScrubsPerYear

 

 

If running vSAN 7.0 Update 1, leave the vSAN ObjectScrubsPerYear set to 1, but ensure it is set the same way on all ESXi hosts in the vSAN cluster.

Additional Information

See KB 318125 for full details on the memory congestion problem, and the workaround.