The default is to have a volume at least twice the size of a LUN to accomodate at least one full snapshot. If you don't need snapshots then you don't need space reservation. Not sure about SQL environments, but in Oracle environments we've seen the need to have larger volume:LUN ratios because log volumes actually change more blocks (proportionally speaking) because you are creating and deleting more files. The data files typically add blocks but don't delete them, depending of course on the database activity. We add data to our Oracle databases, but seldom delete anything.
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Milazzo Giacomo Sent: Monday, December 03, 2007 2:56 AM To: Raj Patel Cc: toasters@mathworks.com Subject: R: Can't expand SnapDrive for Windows drive
Hi Raj,
It's easier than it seems! :-) Anyway I suggest to read the TR 3431 and TR 3541 on "best practice" on SMSQL and SME where the concepts of space reservation, lun thin provisioning and so on are very well descrive.
I take this opportunity to ask here:
The LUN reserved for SnapInfo in SMSQL environments need to be half in size of the containing volume? I don't think so for it has to contain only logs and streamed images of the system db (model, master...). Opinions?
-----Messaggio originale----- Da: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] Per conto di Raj Patel Inviato: lunedì 3 dicembre 2007 3.24 A: toasters@mathworks.com Oggetto: Re: Can't expand SnapDrive for Windows drive
Cheers Bill - that was it.
I deleted a couple of old snaps and a mirror and it gave me enough space to expand.
I think I need to do a 'reserve 101' course . . .
Raj.
On Dec 3, 2007 3:02 PM, Neil Stichbury Neil.Stichbury@gen-i.co.nz wrote:
How do you define 'free space'? Do you have fractional_reserve, snap reserve set?
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Raj Patel Sent: Monday, 3 December 2007 1:16 p.m. To: toasters@mathworks.com Subject: Can't expand SnapDrive for Windows drive
Just trying to expand a 20Gb lun used for SQL 2005 logs - Its contained within a 400Gb volume (I've allocated 140 for the database, 20 for logs and 10 for temp db). The vol is sized at well over twice the space requirements to allow for snaps. I just want to expand the log lun to 40Gb.
Server is w2k3 sp1 SnapDrive 4.2.1 and OnTap 7.0.5 on a fas 270. SnapManager SQL is installed for SQL 2005.
Overall SAN free space is about 80Gb.
From within Windows the error SnapDrive gives is 'Unable to Expand Disk / Error there is not enough free space'
Anything obvious I'm missing ?
Thanks in advance,
Raj.
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