Incremental Backup, CBT and Scheduled Defragmentation

[PariPari]

Hey,

is there any recommendation about the automated defragmentation in VMware Windows Guests regarding CBT Backups?
My guess is, that it doesn't affect machines with low block change rate like printservers or domain controllers. But what about fileservers and suchlike?


best regards

[Vitaliy S.]

Defragmentation will make blocks to change their location, and this will be reported as changed data by VMware CBT, so it does have an effect. If your server is pretty static, then I guess doing defragmentaion should not be required, right?

[PariPari]

Well, it is more a general question and i was looking for some real life experiences
It wont have much effect on server with low block change rate. But what is the impact on servers with a lot of file changes + regular defragmentation occurring? (larger VMs with 4+ TB in size)
Did anyone notice a significant change to incremental backup size/time after a maintenance window (w2012) or the scheduled defrag task (w2008) ?

[Vitaliy S.]

But what is the impact on servers with a lot of file changes + regular defragmentation occurring? (larger VMs with 4+ TB in size)

You will have large incremental data backed up every job run. Please check out this thread for more details > Large VIB file on a small static server