Storage Usage (newbie)

[chris6161]

Hi,

I'm fairly new to this so save me :p

Question 1:

What i don't understand is we hava a volume that is 100GB reported size.(the size that i assigned) It's 66GB consumed space.

When i look at the server the consumed space in data is 28 GB .This is thin provisioned with no snapshots.

On other volume 300GB reported size .consumed 391. on server 30GB. Thin with no snaphshots.

This question is answered in post

Question on Consumed Space size oddity

 by JITUN

How is the calculation off a snapshot?

Question 2.

Our total space 5.6 TB

Our storage is indicating cluster is overproviosened (see attachment)

While cluster storage is showing 61%

Do we need to take this in consideration?

How is the provisionable space calculated over the physical space?

Thx

P.S. This thread has been moved from General to HP StoreVirtual Storage / LeftHand. - Hp Forum Moderator

[oikjn]

First, consumed space also takes into account your network raid, so if you are network raid 1, your consumed space is twice the actual required volume space.

Second, thin provisioning can get you into trouble and you need to understand it and plan for it carefully. The VSA software does not know what parts of your volume are zeroed out and will NOT RECLAIM erased space. Thin provisioning will not allocate capacity for a drive until it is written to. The problem is that if your OS happens to write to 90% of your drive, that 90% is then provisioned and used up even if the OS deletes the files. This means you can show a think provisioned drive consuming even 100% provisioning even if you look at the OS layer and see it only 2% full.

I definitely recomend you use thin provisioning and ignore the warning about overprovisioning (as it is always there if you do a snapshot), but you should plan your provisioning assuming that all thin volumes will become thick eventually.

I highly suggest that you create a 50gb volume called "emergency space space" or something of that nature to ensure that IF you happen to have a volume suddenly expand and fill your array that you can quickly delete that 50gb (or whatever size you want) volume to give you some reserve capacity because all LUNs will become inaccessible when the SAN becomes 100% filled.