I received a call concerning vRanger indicating that it was not deleting the old backup data according to the retendays variable and this in turn, was causing backups to fail due to lack of disk space on the E: drive. The retendays options was set to 7, thus the expectation was any old backup data older than 7 days would be deleted.

Once I connected to the system, I found this vRanger command line:

“C:\Program Files\vizioncore\esxRanger Professional\esxRangerProCli.exe” -virtualcenter vc2://Datacenter=datacenter-2 -copylocal E:\VRanger -drives:db -zipname [config]_[weeknum] -vmnotes -noquiesce –diffratio 50 -onlyon -vss –maxfullage 7 –retendays 7 -mailto support@abcinc.com

The variables in bold are as follows:

DIFFRATIO
If the Enable Automatic Differential Backup flag is checked, this option helps to determine if vRanger will create a differential backup instead of a full backup. If the size of the most recent differential backup of this VM is greater than the percentage of the full VM size indicated here, then vRanger will create a full backup.

MAXFULLAGE
If the Enable Automatic Differential Backup flag is checked, this option helps to determine if vRanger will create a differential backup instead of a full backup. If it has been more than the number of days* indicated here since the last full backup of this VM, then vRanger will create a full backup.

RETENDAYS
This option determines how long vRanger will keep an archive before it is deleted to free up hard drive space. When creating a backup, vRanger checks all existing backups of the same VM with the same destination – any backup which is older than the number of days indicated here is deleted.

Basically, ABC was under the impression that vRanger would run a Full Backup every 7 days and also delete any backups older than 7 days. However, there is a problem with that assumption. The variables in bold above will only work if the AUTODIFF variable is enabled. As you can see, in our backup command above, AUTODIFF is not specified, thus the other variables are being ignored.

By adding the –autodiff variable to the vRanger command line, a full backup should be taken every 7 days, with differentials the 6 days in between.

Using the –autodiff variable reduced the amount of space used on the E: drive, thus reducing backup job failures due to limited disk space. But, we come to yet another item to consider in regards to the –retendays option. When using retendays, full and differential backups are not deleted until all differential backups associated with the full backup are older than the number of days indicated.

So, if a full backup runs on December 1st, differentials will run until December 7th, followed by a full backup on December 8th, and then differentials until the 14th. Since backups jobs cannot be deleted until all backups associated with a full backup are older than 7 days, vRanger won’t be able to delete old backup files until December 14th, at which point it would delete all backups from Dec 1st – Dec 7th.

When building your vRanger scheduled task(s), be sure to know any variable dependencies to avoid unnecessary confusion. Documentation for vRanger Pro can be found here.