Reverse Incrementals on Hyper-V

Userlevel 2

I recall from one of the recent Veeam R&D Forums Digest newsletters that Reverse Incremental for Hyper-V is being removed or has been removed in VBR.  This is useful for sending full backups to Tape, otherwise we have to do synthetic full to Tape (heavy use of virtual memory for our TB-sized backups) or create a synthetic .VBK (use more disk space).

Which VBR version did Veeam start doing this?  Luckily still on 9.5

I feel like Hyper-V is getting short-changed ...



Best answer by JMeixner 22 January 2021, 15:29

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Userlevel 7
Badge +15

Reverse Incremental for Hyper-V is described in the user guide for Version 10.

So I it is not removed in V10.

For V11 I cannot check this, I don’t have a Hyper-V installation with a VEEAM V11.

Userlevel 7
Badge +20

I’m not aware of any news on reverse incremental going away in any form, so if so this is news to me as well. I know that with XFS and ReFS repositories the recommendation has shifted from using reverse incremental for most use cases as these have a higher IO penalty compared to Forward Incremental and the additional space consumption is mitigated by Fast Clone which will reference existing blocks where possible instead of copying duplicate data blocks. I understand this wouldn’t change your requirements for Tape, but from a primary repository perspective I do recommend ReFS with Forward.


Further info here if interested: Fast Clone - Veeam Backup Guide for Hyper-V

Userlevel 7
Badge +12

I just searched latest newsletters for this. I could not found any note to removing reverse incremental for Hyper-V. Just a commend of @Gostev about reverse incremental in general.


About your tape full-backup fear: You can use GFS media pools. Here each tape-backup (with exception of daily backups) are fulls. Furthermore you can use virtual fulls as well. Virtual fulls need just a few MBs on disk.