Snapshots requirements question

[arthurvino1]

Planning a purchase of iSCSI SAN (Equallogic/Lefthand)

VCB proxy server with vRanger and ArcServer 12 tape backup will be used for backups.

How much space do I need for snapshots on the SAN?

Is it exactly a double of used data (thin provisioned)?

Is there compression or any formula for figuring this out?

Lefthand writes to 2 boxes (Network Raid), so the snapshots are not needed at all?

Also, if the snapshot is only 10% of original data (delta file) and the original file is corrupted/lost - then the snapshot is unusable since u cant create a full file from 10% of it? I am a bit lost on this topic.

Any help greatly appreciated

[azn2kew · Accepted solution]

This blog can help you understand how snapshot works and disk rate growth from Eric Siebert.

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Regards,

Stefan Nguyen

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant

[weinstein5]

snapshots are not a copy of the virtual disk but a method that allows the ESX host to log block level changes ot the virtual disk and record a system state image of the disk - so if you run snapshots for a short period they should not be that large -

[azn2kew]

We do not recommend using snapshots too much. It would be preferrable for a short period of time for patch/update testings. Once verified its function, you should remove snapshots because if you left it long time and the disk size growth and its hard to remove and can take a long time to commit.

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Regards,

Stefan Nguyen

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant

[arthurvino1]

Thanks all.

azn2kew - what do you use to backup instead of snapshots? straight to tape?

[azn2kew]

Backup solutions for VMware comes in many options so you might have to deploy it and test it also compare licensing cost as well. For large environment, people like to use Vizioncore vRanger. Veeam Backup is new but its shows really good product and easy to work with. VCB is free with VMware enterprise license so its worth looking at but requires a windows 2003 proxy server as well and works fine with existing backup software such as Veritas BackupExec, CommVault, etc..Phd esXpress is also come with both free and license version and its virtual appliance base and it works well too. There are free script and tools such as VISBU from xtravirt.com you can check out for details.

It really depends how big your backup environment works, for small business you can use VISBU or esXpress for free. I'm a consultant so each cilent has different solutions depends on their budget and environment. If I have a choice, using vRanger and Veeam Backup is the easiest to backup/restore.

You can view backup solutions comparision from Edward Haletky at www.vmprofessional.com which is really. Good luck.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen

iGeek Systems Inc.

VMware, Citrix, Microsoft Consultant