Handling of large VM's with delta backups
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We have a handful of mission critical VM's that are 1-2TB in size (VDI is set to 2TB but most of them are already 1TB+ in size). With delta backups, are there any overhead to be expected when doing comparisions between the backup VHD's and the ones running on the server? Most of these still run on spindle drives so just want to understand how data comparison works (AKA are you comparing 2 large files for changes or is there something like CBT enabled to track changed blocks?)
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Bigger the VM disk, longer the backup time. That's pretty much it. Also, larger transfer are more prone to issues (because longer time to backup means more chance to get a problem during the transfer).
Anyway, it's all VHD diff based, not CBT.
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@olivierlambert said in Handling of large VM's with delta backups:
VHD
Backup time is fine, we're currently exporting the entire VMS each weekend, so I am use to the backup time, I was more referring to the comparison / diff and if that has any impact over network (I assume that comparing 2 large files over network could cause some overhead, and I guess the larger the file the bigger chance for network congestion)
We're going to start testing this weekend to see what results we get
Will keep you posted -
The delta isn't computed over the network, but directly on the host itself
