> > And if the ZFS is supposedly smart enough to use request coalescing > > as to minimize mechanical seek times, then it might actually be > > possible that your disks would get "stuck" averagely serving > > requests > > from different parts of the platter, i.e. middle-inside and > > middle-outside > > and this might even be averagely more than 2x faster than a single > > drive (due to non-zero track-to-track seek times). > > In practice I've just found out I'm completely CPU-bound. > Load goes to >11 during scrub, dd a large file causes ssh > to crap out, etc. Completely unusable, in other words.
That's I/O-bound, not CPU-bound. The CPU load is likely to be rather low during scrub, but the I/O load will be high. IIRC this is tunable, at least in Solaris and friends. Also, adding SLOG/L2ARC will help a lot to make the system more resposible during scrub/resilver, again, at least on Solaris and friends. 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
