This now becomes the 3rd post regarding the infamous Changed Block Tracking bug that was/is evident in all versions of ESXi 4+.
Finally today we see the bug squashed in ESXi 5.5 with the release of Patch ESXi-5.5.0-20150104001-standard (2099271).
This still leaves 4.x susceptible though so I urge any good folk using it to exercise their due diligence mitigating the impact using one of the workarounds, or UPGRADE !
For consistency & completeness, I hope 4.x does get the fix ported to it.
When you use backup software that uses the Virtual Disk Development Kit (VDDK) API call QueryChangedDiskAreas(), the list of allocated disk sectors returned might be incorrect and incremental backups might appear to be corrupt or missing. A message similar to the following is written to vmware.log:
DISKLIB-CTK: Resized change tracking block size from XXX to YYY
More details can be found in the KB
This updated build also bundles in other fixes including,
- Degraded Storage vMotion performance on thin VMDK’s.
- PSOD’s for hosts using vFlash read cache
- VM’s with PVSCSI controllers may stop responding or fail
and a heap of other fixes of various importance, detailed in the KB linked above.
This also corresponds to a vCenter build update to 5.5Update 2d , with details here
Go at it..