Forward Vs Reverse Incremental backup for disk space considerations.

[vijay.mc968]

Hi Folks.

We are using forward incremental backup method for all our veeam jobs and it is working well so far.
We have space crunch on backup repository, so I am revisiting if anything can be done for disk space optimzation.

I read in articles that reverse incremental use less space and preferred for tape backups (We are using disk backups only), So I am checking how I can modify current forward incremental to reverse once without effecting our backup goals. I am giving below example..

Goals: (We have setup with current Forward Incremental backup method)
Restore points to keep on disk : 14 Days.
2 Full backups weekly (Synthetic full on Wednesday, Active full on Sunday)
So rest of other days it is Incremental.
Let's say one Job consuming 500 GB for 14 days restore point.


How I can implement reverse incremental to minimize disk space usage and keeping 2 full backup restore points...as I read reverse incremental keep latest restore point as full backup and rest copies are incremental.

[PTide]

Hi,

<...>I read in articles that reverse incremental use less space

That is true only if you compare reverse with one full against incremental with multiple fulls. If you compare reverse with forever forward there will be no difference in terms of space consumption.

How I can implement reverse incremental to minimize disk space usage and keeping 2 full backup restore points...as I read reverse incremental keep latest restore point as full backup and rest copies are incremental.

Right, the latest point for reverse is full backup, however if you schedule another full for the same job then there will be no space savings at all. Also please note that reverse mode requires 3x times more IO than regular incremental mode.
Check this backup calculator to get an estimate for different configurations.

Thanks!

[vijay.mc968]

Thanks for help.

Then how can be optimize disk space usage with current setup and goals.

[PTide]

Hi,

That depends. What do you use as repository, and do you have a secondary backup location?

Thanks

[vijay.mc968]

SAS storage disks are being used as repository. And Yes, out of 2 servers, we are using secondary backup location as well.

[PTide]

Well, I meant "what type of repository". If you use Windows-based repo, then you might try to go with ReFS deduplication. Other than that you can reduce the main backup chain length while increasing the one.

Thanks!

[vijay.mc968]

Yes, it's Windows Based repo on both Veeam serevrs. Let me check ReFS deduplication feature.

Thanks for guide.