> > 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 -- Roy Sigurd Karlsbakk (+47) 97542685 r...@karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
