Forward incremental with active full

[MatMatMat]

I'm not sure I fully understand how this all fits together yet but I'm struggling to wrap my head around this issue:

If we run daily forward incremental, with 7 restore points, and an active full on Sunday evenings, does the new active full backup render the previous week's incrementals useless if the previous active full, which they were dependent on, is deleted due to the 7 restore point retention
or
would the previous weeks incremental files be able to look at the active full they were dependent on, (now deleted due to retention policy) but which was archived in the backup copy job?

Many thanks!
MMM

[Shestakov]

Hello,
Increments of the older chain will not be deleted until all of them are outdated, i.e. until you have 7 restore points in newer chain.
Thanks!

[MatMatMat]

So I'll end up with 13 restore points: 7 from week one and 6 from week two, the 14th restore point prompting the removal of the entire chain from week one leaving me with the 7 from week two?

[Shestakov]

Yes, you will have from 7 to 13 restore points, depending on the day.

[MatMatMat]

Super, thanks.
MMM

[doddsyuk]

So I'll end up with 13 restore points: 7 from week one and 6 from week two, the 14th restore point prompting the removal of the entire chain from week one leaving me with the 7 from week two?

This was why I switched to reverse incremental, that why you only ever have 7 points which will reduce your storage requirements. There are some disadvantages to this but I can't remember what they were.

[Shestakov]

Hello Chris and welcome to the community!
I would also suggest checking forever-forward incremental as it works faster than the reverse one.
Thanks!

[doddsyuk]

Thanks, I had considered this but was under the impression forward increment restores were slower than reverse incremental restores when restoring to the latest backup, restores are usually more time critical than backups and I don't really have any speed issues for my backups, I only have 35 VM's to backup and only run 14 jobs (12 incremental and 2 full backups) max per night.

[skrause]

The speed of the restore for Forward incremental really depends on your change rate and the number of increments after the full. Reverse will have the fastest restore time but it has the largest impact on production operations because the snapshots are open longer during the backup window. I have done restores of machines that had 5 increments that didn't take noticeably longer than restoring from a full that had run the day before.

In many cases I have had the ingest rate on the storage I am restoring to be the bottleneck which renders the difference in backup type moot.

[JoshuaPostSAMC]

This was why I switched to reverse incremental, that why you only ever have 7 points which will reduce your storage requirements. There are some disadvantages to this but I can't remember what they were.

For me, the speed of the backup job when running Reverse Incremental was significantly slower. 3 MB/s vs 60+ when doing forward. I would much rather have faster backups with the chance I need a restore that may run a little slower, compared to suffering the speed penalty every day.

I've restored VMs with 30 recovery point retention with Forward Forever and it seems to restore just as fast as I am backing up, although I don't have specific numbers. Still, I can restore a 100 GB VM in under 10 minutes. if you turn on restoring only changed blocks, it may be even faster.

[doddsyuk]

For me, the speed of the backup job when running Reverse Incremental was significantly slower. 3 MB/s vs 60+ when doing forward. I would much rather have faster backups with the chance I need a restore that may run a little slower, compared to suffering the speed penalty every day.

Wow that is slow, I am getting minimum 30mb/s on my reverse backups and as they finish by the time I need them to i haven't worried about the speed.

[skrause]

Reverse incremental performance is primarily tied to the random I/O performance of your backup repository.

[Shestakov]

Forever forward pro and cons were discussed in details in this topic.
Thanks!

[doddsyuk]

Useful link thanks Nikita

one question, with the forever forward how can you be sure of the integrity on of the full backup? I know you can perform health checks but the information here

https://helpcenter.veeam.com/backup/vsp ... check.html

seems to imply that it only checks the integrity of the latest incremental backup performed at that point, as the forever full backup is constantly being changed what checks are in place to guarantee that your full backup which all your other backups rely on is a good backup?

[Shestakov]

It`s recommended to use recovery verification such as Surebackup for that.
Here is another good topic to read.
Thanks!