Convert job from forward to reverse using transform?

[KevinB66]

Hello VEEAM community!

I'm using B&R 9.5 U2 at present. I have a number of jobs that are currently set to use forward forever incremental. For all but one this is fine, but for convenience I'd like to change one job to reverse incremental.

I have read Switching Between Backup Methods which tells me that doing so will create a new Full on my repository and then use reverse incremental from that point onwards, leaving the old forward chain in place and starting a new chain.

Is it possible to get around that by first changing the settings of the forward incremental job to include Backup Chain Transform and allowing the job to run once in order to convert the chain into a reverse chain, and then change the job type to reverse incremental?

By doing so I'm hoping to avoid having two full backups left on the repository as there is limited space available long term.

Any answers, help or advice gratefully received

[Shestakov]

Hello Kevin and welcome to the community!
Synthetic full first creates new full backup from increments and then deletes the older one in accordance with retention. If you don't have enough space on repository for 2 full backups and increments, the trick will not work.
Thanks!

[KevinB66]

Thanks for the reply Nikita
Sounds like it should work as hoped then as I have enough space for two fulls plus increments now but wouldn't have had room for two fulls plus increments long-term.

[Shestakov]

You are welcome.
I've never tried the trick, but In theory it should work fine.
Thanks!

[foggy]

Hi Kevin, just to confirm, it should work if you switch modes right after synthetic full creation, both with or without transform. Another full will not be required - the newly created full will serve as the base for reverse incremental chain.

[KevinB66]

Great, thanks for the confirmation

[Shestakov]

Another full will not be required - the newly created full will serve as the base for reverse incremental chain.

My point was that you need space to perform the transform, once transform is finished, older full will be removed automatically.

[KevinB66]

Just to confirm that this method of switching from forward forever incremental to reverse incremental worked fully.

It also worked in a cleverer way than I expected. Rather than leaving the original vbk and creating a brand new synthetic full it walked the initial full vbk forwards transforming each vib to vbr as it went. This meant that it did not need space for a second full backup on the repository as it worked. It took far longer than anticipated as a result, but it was more conservative on space required.

[Shestakov]

Good to know, thanks for the update, Kevin.