We currently have both sides of this particular scenario: systems with only one massive aggr with the root vol contained within, and systems with a separate aggr\root vol and other aggrs dedicated to data. It depends on the system: FAS250, or FAS270 (especially the single-shelf variety), it is a WASTE of a system to have a separate aggr for root. With some of the larger sized systems, it typically doesn't matter if you suddenly lose 3 disks out of 50+.

The traditional reason to keep the data sets separate is recovery: losing both the root vol and data would be a terrible shame. However, the chance of losing 3 disks across a single RG is almost NIL. Even then, I'd rather lose my root than my data.

The other reason is performance: having a heavy I/O load on data access could cause problems for filer performance if the root vol were to be co-located within the same physical disks. Again, the chance of having that type of issue with an extremely large aggregate isn't very high.

Between the two above arguments, there aren't a lot of reasons not to put it all together.

Glenn

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From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Fox, Adam Sent: Wednesday, January 24, 2007 3:34 PM To: Linux Admin; NetApp Toasters List Subject: RE: 1 disk shelf with 1 head....using just aggr0

I would just grow out aggr0 and save the space. There are only a few corner cases

where having a dedicated root aggr makes any sense and they are rare. So while it may

be nice to have, I wouldn't bother on a system of that size. It would, indeed, be a horrible waster

of space.

With one shelf of disks, 99% of customers should set up a single RAID-DP aggregate with a single

spare. There are exceptions, but without knowing anything else about your environment or future

growth plans, that's what I'd do.

-- Adam Fox adamfox@netapp.com

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From: Linux Admin [mailto:sysadmin.linux@gmail.com] Sent: Wednesday, January 24, 2007 2:39 PM To: NetApp Toasters List Subject: 1 disk shelf with 1 head....using just aggr0

Would anyone recommend not using/growing aggr0 if I only have 1 disk shelf Currently I have 1 vol0 in agr0 (1 data disk + 2 paratiy) I would think that creating a second aggr would be just enormous wast of 300GB disks What is the best practice? Should I just grow the aggr0? Thanks