Newbie Questions about disk storage for Veeam

[vgeek]

Hello my heroes,

I am in need to get answer to a few questions to make some purchasing decisions and will appreciated your comments and recommendations.

I have a 3 ESXi 5 host environment. Due to storage limitations I am only virtualizing a few of my production and test/dev servers. Mainly non IO intense servers. I inherited most of these limitations but they will corrected next year.

The Veeam server I'm using is a PowerEdge R710 with Intel Xeon E5504 CPU @ 2GHz. The server only has two mirrored 146GB 15k HDs. I have always done my backups to tape so having such small amount of storage on the backup server has never been an issue. I currently have about 70GB of storage free on the server. For next year's budget I will be able to add a new SAN and more storage but for now I need to be able to backup about 6 or 7 VMs to disk and the to tape. The size of the VMs are from 25 to maybe 60GB. Without having to rebuild my server, I can add another for HDs to server.

I don't need to store backups for weeks, at least not for now. I just want to make sure that I can get a full backup to tape every day to send to the bank. Currently we do a two week tape rotation. Some of the backups are incremental during the week with a full backup on friday and others are regular full backups.
What's the minimum amount of storage I can get away having until I can get a new SAN? Based on this information can you recommend the type of backup (incremental, reverse, synthetic vs regular full, etc.?

Thanks in advanced for your help.

vG

[dellock6]

If this is going to be only a temporary solution, the less expensive way is adding another couple of large SATA disks to the R710, join them in a Raid1 (or 4 disks in a Raid10 if performances are too slow), and use this space for Veeam backups.
Since the VM are not so IO intensive, you can use Reverse Incremental with 14 days of retention, so you will re-create the two weeks rotation of the old solution, and at the same time you will have always the last backup beeing a full one, ready to be offloaded to tape where you will always have a full version of it.

Luca.

[vgeek]

Grazie Luca,

Assuming the total size of the backup before compression and dedupe is 400GB how much minimum requred storage would I need?

I still have to get my head wrapped around the incremental vs reverse incremental backups as I don't understand them very well. But I noticed on other post you recommend to use incremental if the full backup needs to be offloaded to tape. Why do you recommend reverse incremental instead?

[dellock6]

Because I misread you opening post
Was thinking about periodic offload to tape, sorry. If you need daily offloading, then forward incremental is the way to go, absolutely, since once created the backup file is not touched anymore so the tape backup software can run in incremental too without saving the same file multiple times, and it only get the new one.

About space requirements, it really depends on the daily change of the CBT blocks and the data inside the VM (some can be highly compressed, others not so well). let's say you can have a reduction ratio of about 80% (a number I got from a Veeam SE about average reduction across their customers):
- your initial backup can be reduced to 80-100 Gb
- after this, if you have a daily change of 10%, this is 10 Gb daily
- with a 7 day retention in forward incremental, you end up having 2 full and 12 incremental
- 100*2 + 10*12 = about 320 Gb

go for a couple of 1Tb SATA drive in raid1 and you are ok, but don't pick these numbers as an absolute truth

[Vitaliy S.]

If you're using tapes to offload your backups, then Luca is correct that you need to use forward incremental backup mode, however I've just re-read your initial post where you've mentioned that you need to offload a full backup to tape every day:

I just want to make sure that I can get a full backup to tape every day to send to the bank.

If this is the case, then you should configure your jobs to use reversed incremental backup mode and offload VBK (full backup) file to the tape.

As to storage space calculations, then please take a look at this thread, might be useful: Estimated Required Space Report?

By the way, we have a very informational sticky F.A.Q. topic which should help to understand backup modes differences:
>>> READ FIRST : [FAQ] FREQUENTLY ASKED QUESTIONS <<<

Thanks!

[dellock6]

Ouch, thanks for this post Vitaliy, that was why I told in the first post it was good to use reverse incremental. I was right and I correct myself for nothing...