So here we are again, rounding the year off with yet another change block tracking warning.

I’ve written posts previously on the CBT bugs found in 5.5 and below and those found when vSphere 6.0 was released into the wild.

So whats the issue this time?

Basically it is the same as last time, the wrong sectors of data locations are returned by CBT when requested by your backup software. Meaning it targets the wrong data to backup.

Here is the official VMware KB 2136854. Which describes the following;

When running virtual machine backups which utilize Changed Block Tracking (CBT) in ESXi 6.0, you experience these symptoms:

 - The CBT API call QueryDiskChangedAreas() API call can sometimes      return incorrect changed sectors, which results in inconsistent  incremental virtual machine backups.

 - Inconsistent virtual machine backups

All incremental backups which utilize CBT are potentially affected.

Anton Gostev, Veeam, has released a lengthy email to Veeam customers and Gostev lovers stating the following (you can follow the veeam forum post here); Continue reading Yet again, ESXi 6.0, CBT issues #vDM30in30 →