[zfs-discuss] One dataset per user?

Roy Sigurd Karlsbakk
2010-06-21T09:00:08Z

----- Original Message -----
> On Jun 20, 2010, at 11:55, Roy Sigurd Karlsbakk wrote:
>
> > There will also be a few common areas for each department and
> > perhaps a backup area.
>
> The back up area should be on a different set of disks.
>
> IMHO, a back up isn''t a back up unless it is an /independent/ copy
of
> the data. The copy can be made via ZFS send/recv, tar, rsync, Legato/
> NetBackup, etc., but it needs to be on independent media. Otherwise,
> if the original copy goes, so does the "backup".

I think you misunderstand me here. The backup area will be a storage area for
Ahsay (see http://www.ahsay.com/ ) for client and application (Oracle, Sybase,
Exchange etc). All datasets will be copied to a secondary node either with ZFS
Send/receive or (more probably) NexentaStore HA Cluster (	http://kurl.no/KzHU ).

> > I have read people are having problems with lengthy boot times with
> > lots of datasets. We''re planning to do extensive snapshotting
on
> > this system, so there might be close to a hundred snapshots per
> > dataset, perhaps more. With 200 users and perhaps 10-20 shared
> > department datasets, the number of filesystems, snapshots included,
> > will be around 20k or more.
>
> You may also want to consider breaking things up into different pools
> as well. There seems to be an implicit assumption in this conversation
> that everything will be in one pool, and that may not be the best
> course of action.
>
> Perhaps one pool for users'' homedirs, and another for the
departmental
> stuff? Or perhaps even two different pools for homedirs, with users
> ''randomly'' distributed between the two (though definitely
don''t do
> something like alphabetical (it''ll be non-even) or departmental
> (people transfer) distribution).
>
> This could add a bit of overhead, but I don''t think have 2 or 3
pools
> would be much more of a big deal than one.

So far the plan is to keep it in one pool for design and administration
simplicity. Why would you want to split up (net) 40TB into more pools? Seems to
me that''ll mess up things a bit, having to split up SSDs for use on
different pools, loosing the flexibility of a common pool etc. Why?

Vennlige hilsener / Best regards

roy
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Roy Sigurd Karlsbakk
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roy at karlsbakk.net
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