Hyper-V 2012 R2 Incremental backup: Would the checkpoint filling up the disk?

[kf2013]

I know a checkpoint will leave after the backup. I am wonder how much space do I need for it? I am afraid it would filling up the disk. However, i can't find any information of Hyper-V incremental backup from Microsoft. I know it will increase the backup performance, then will it affect the VM performance?

[CraigV]

If the snapshots are not deleted, then BE will eventually fail backups with no disk space and this in turn will cause issues with Hyper-V. Your best bet is to look at how much overhead you require on Hyper-V to keep free disk space as a Microsoft best practice (VMware is 25% of the data store) and make sure you don't drop below this, or increase the amount of disk apce on the Hyper-V volume/s.

The size of the temporary snapshot/checkpoint would be dependent on the size of the VM and the amount of changes made to the VM since the previous backup.

Thanks!

[Gurvinder]

Refer https://www.veritas.com/support/en_US/article.000100786 . I did a few tests and any given time there is 1 avhdx present (differencing/snapshot disk). Since I had smaller VMs and there wasnt much changes I did on that VM, the size of the snapshot disk was small but in reality it depends on how much data is changing because the changes would go into the avhdx i.e. differecing disk or you can call it the snapshot.Less changes go into that file, smaller the size of the avhdx file will be. Even performance may vary depending on a lot of factors. If you were Ok with the earlier standard settings, then you can follow the technote I mentioned to revert to earlier way of backing up Hyper V VMs.

[kf2013]

https://www.veritas.com/support/en_US/article.000100786

Since installing FP3, it can be seen that Hyper-V backups now create a checkpoint (and associated AVHDX files), however even when the backup job finishes, a checkpoint now remains linked to the VM although the checkpoint will be updated during subsequent backup processes.

[kf2013]

I know it would have a performance impact. I am afriad the snapshot file avhdx would filling up the disk if I suddenly have a big changes in the VM. I also found a problem of faster processing. Because a checkpoint is created, so you can't expand the virtual disk. YOu have to delete it before you are going to expand the virtual disk. Seem the faster processing is not really flexible.