[OpenIndiana-discuss] [zfs-discuss] iops...

[Roy Sigurd Karlsbakk]

> > I am totally aware of these differences, but it seems some people
> > think RAIDz is nonsense unless you don't need speed at all. My
> > testing shows (so far) that the speed is quite good, far better than
> > single drives. Also, as Eric said, those speeds are for random i/o.
> > I doubt there is very much out there that is truely random i/o
> > except perhaps databases, but then, I would never use raid5/raidz
> > for a DB unless at gunpoint.
> 
> Well besides databases there are VM datastores, busy email servers,
> busy ldap servers, busy web servers, and I'm sure the list goes on and
> on.
> 
> I'm sure it is much harder to list servers that are truly sequential
> in IO then random. This is especially true when you have thousands of
> users hitting it.

For busy web servers, I would guess most of the data can be cached, at least over time, and with good amounts of arc/l2arc, this should remove most of that penalty. A spooling server is another thing, for which I don't think raidz would be suitable, although with async i/o will streamline at least some of it. For VM datastores, I totally agree.

Vennlige hilsener / Best regards

roy
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Roy Sigurd Karlsbakk
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roy at karlsbakk.net
http://blogg.karlsbakk.net/
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