Disk usage on Backup Copies

[readie]

I have a 3TB server backing up, and then backup copies daily keeping 2 restore points, asking it to keep weekly for 3 weeks, monthly for 2 months, quarterly for 3 quarters, and annually for ever.
What is the likely cumulative HD usage? Given a saving for compression (lets assume it's a 2.5TB VBK) will I need 1 vbk file for the daily, one for the weekly (and the other two weeks will be VIBs?), and 1 for the monthly, 1 for the quarterly, and then one for every year . . . so after about a year will require 5 x 2.5TB = 7.5TB
I haven't done the calculations, but if our server is not changing much, it could be more economical (if my understanding so far is correct) to keep 11 monthly and no quarterly (i.e. only one VBK + 10 VIB, rather than 2 VBK and 4 VIBs).
Can anyone confirm these ideas, or explain better please, as we are just starting this process, and I need to forward plan!

[foggy]

Bob, all GFS restore points are stored as full backups (1 VBK for each restore point), i.e. you will come up with multiple VBKs for weekly, multiple VBKs for monthly, multiple VBKs for yearly, etc. and only one VIB for the current day.

Also, I would note that with default compression and dedupe levels, VBK typically takes at least 50% of the original data and usually even more (depends on the data stored on virtual disks and some other factors).

[readie]

Thanks Foggy - even worse than I thought! I saw just one VIB, so that must be for my daily 2 restore point. I'll have to rethink our policy I think.
Is there yet any/much experience of using Windows 2012 with its DeDupe as the Backup Repository, in order to try to reduce what's beginning to look like 10 x 2.5TB each year . . . . Certainly our weekly VBK files should be very similar, so DeDupe should be able to reduce them significantly . . .?
Or are there any other techniques other users have found to keep the sort of backup copies (of a 3TB fileshare, and we have another I haven't started on yet!) that we are?

[foggy]

Yes, using Windows 2012 deduplication on backup repository is quite a widespread approach among our customers. You can search this forum for existing discussions where they share their findings and recommendations.

[readie]

Sorry to ask another here (rather than trawl for Windows 2012) but quite a technical question. I know if I take a straight copy of our fileserver, and then another a month later, it will be 90% identical (good for dedupe I hope) . . .but does the backup process, and its own compression and dedupe mean that the two VBK files might NOT be 90% identical? i.e. does Veeam 'mangle' the original in such a way that dedupe is less effective after taking two VBK files a month apart? Hope you see what I mean?

[veremin]

It seems that you’re talking here about straight copy conducted on a file level. Meanwhile, Veeam works on image level. That being said, even though in the end of the month the files on the file server can be 90% identical to those that were present in the begging of the month, the actual blocks of Virtual Machine might have changed dramatically. And once backed up, these blocks might not necessarily be viewed as similar to those that have been backed up previously.

However, it’s just a matter of making speculations – tests should give the final answer.

Thanks.

[yizhar]

Hi.

The new backup copy option is a nice and interesting feature.
However keeping all your backup history on a single deduplicated volume has a risk of loosing all of them in case of problems with that volume.

You can also consider the simple alternative - a set of rotated USB3 disk drives (and of course USB3 controller), used for backup history retention.

You can also mix and match, for example:
Primary backup on primary repository = daily.
USB3 disks = weekly (keeping at least one of them offsite).
Backup copy job = Monthly/Quarterly.

Or vice versa.

Just my thoughts.

Yizhar