Eire09
Enthusiast
Enthusiast

LUN - Recommended free capacity per LUN?

Hi,

What is the recommended size of free LUN capacity that should be left available per LUN?

Thanks in advance,

Peter

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4 Replies
UmeshAhuja
Commander
Commander

Hi,

Very informatory link as per your query.

http://www.gabesvirtualworld.com/storage-how-to-size-your-luns/

Thanks n Regards Umesh Ahuja If your query resolved then please consider awarding points by correct or helpful marking.
continuum
Immortal
Immortal

that depends on many factors

do you use thin provisioned VMs ?
do you use snapshots ?
do you run automatic backup-tools ?

the formula I use for LUNs that use thick provision and no snapshots is

for every VM that usually runs on that LUN sum up its vRAM + 1 Gb

so if you have 10 VMs using 4 GB of vRAM the result would 50 Gb as the minimum required free space - enough to suspend each of them in an emergency.
If you use snapshots or thin provisioned VMs you of course need more than that

Do you need support with a recovery problem ? - call me via skype "sanbarrow"
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Eire09
Enthusiast
Enthusiast

Thanks for your reply.

We don't use Thin Provisioned LUNS

We use Snapshots & our backup solution is Netbackup that uses Snapshots. 

How do I work out how much free space is needed in this case?

Thanks again.

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continuum
Immortal
Immortal

the idea is to survive at least one day ...
so assume your backup-tool runs amok and does not clean up the daily snapshots
do a rough calculation of the space required for such  a scenario and add that to the value you need for a emergency suspend of all VMs

Do you need support with a recovery problem ? - call me via skype "sanbarrow"
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