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-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Jordison (AU) Sent: Wednesday, May 04, 2005 12:31 AM To: toasters@mathworks.com Subject: Simple Question on QTREES and Volumes

Hi,

I will preface this by stating that I am very green when it comes to NetApp things.

I was in the same position last year. Still am to a certain extent. http://now.netapp.com is your friend!

OK, we have a Filer (not sure of the exact model...I can post that if needed) and I am not sure of the level of software we use (once again I can find this) but my question is about Disks, Volumes and Qtrees.

The Model does not matter too much. But the version of DataOnTap is important. We're currently running version 6.5x. Version 7 brings extra functionality (flex Vols).

A volume is a bunch of disks (LUNS) yes? - ie if I get 5 66GB disks RAID 4 it gives me about a 200GB volume? - The size of the volume is directly proportional to the amount of disks added to it??

Yes, a volume is just a bunch of disks.

Qtrees are effectively virtual volumes that 'break up' the volume even more (ie a 200GB volume can have 8 x 25GB Qtrees (or 1 x 50GB Qtree and 6 x 25GB Qtrees)?

No, Think of a qTree as a folder on a disk. You can assign quota to a qTree to control how much it will grow. 5 qtrees on a 500 meg volume = each qtree can store a max of 500 meg. Or a combination of 500 meg till the disk gets full.

Qtrees can be increased or decreased at any level (if I add a disk to a volume all of that space can go to a Qtree or none of it while the volume MUST increase by the amount of physical disk added?

Only adding disks to the volume will affect the total space available to all qtrees. Space assigned to qtrees is controlled by quotas.

If I want to put data on the filer (say Exchange data, user homedrives and Departmental data) I can put this data on separate Qtrees in a single volume? Or should I put the data on separate volumes and not worry about Qtrees?

It's your choice. We have four volumes currently. One for livelink data One for UNIX data Two for the NT Stuff. Putting a quota on home drive was one of my directives so I have 5 qtrees dedicated to home drives. Two trees with a default quota of 250 meg / user. One with a 500m / user, one @ 1 gig / user, the last one is a 2 gig / user default plus the folders of those that go over 2 gig (quotas have to be applied manually for the over 2 gig users). The rest of the space on the NT volumes are used for departmental shares. These shares reside in their own qtrees. These qtrees have tree quotas on them (mainly to limit growth).

Is it better to have 1 massive volume and split it into qtrees as needed or is there a limit on volume size (performance problems if volume too big?)?

There is a limit of 250 qtrees per volume if I recall correctly. Any folder you put in the root of a volume is considered a Qtree.

Sorry if this is totally incorrect...if it is please feel free to correct me as I said I have had nothing to do with NetApp stuff before (although I am quite handy on a HDS SAN :)) But if I am right, please let me know as I need this information.

Sorry for taking so long with this email.

HTH if I can.

Grant Warkentin System Administrator II City of Calgary - Information Technology Mail Drop == 8245 Ph: (403) 268-5629 Fax: (403) 268-2546