Large incremental on OS drives

[mattvogt]

I'm seeing very large incrementals for most VMs OS\App drives. First the setup:

B&R 7.0R2-latest
Backup over WAN (extreme compression, WAN optimized)
vSphere 5.5
Nutanix host/storage
local proxy
network mode backups
No local repo, all over WAN
Incremental nightly, synthetic full weekly

Most VMs are showing 1.6GB of change per night, and some are in the 5-6GB/night range. I would expect this to be much lower.
For instance, in a separate environment, I have a AD controller with about 800MB read (200MB transferred). But in this environment, an AD controller is reading about 2.5GB/night (no other roles or apps).

My thoughts are around the way Nutanix does data localization and clustering and wondering if that's causing more blocks to change than the OS is actually changing.

Appreciate any help.

[Gostev]

Unless Nutanix causes additional write I/O from within each guest, I am not sure how it can affect the situation. Perhaps just some strange app or antivirus causing a lot of modifications. Or, awfully fragmented disks in the guests. Or very active AD the difference is just 3 times anyway, more active AD and worse fragmentation can easily get you there.

[Vitaliy S.]

Hello Matthew,

There is an existing topic covering a similar question, should be useful > Large VIB file on a small static server

Thank you!

[dellock6]

Knowing the Nutanix architecture, there is no inner reason their storage system could lead to dufferent results, the write replication happens below the NFS export so from an hypervisor perspactive, there is no difference from a usual NFS storage. So as others said the only possible reason is there could be some difference in the daily changes in those VMs. Matt, it's only about those Domain Controllers, or it's happening to other VMs too?

Luca.