On Nov 4, 2009, at 6:02 PM, Jim Klimov wrote: > Thanks for the link, but the main concern in spinning down drives of a ZFS > pool > is that ZFS by default is not so idle. Every 5 to 30 seconds it closes a > transaction > group (TXG) which requires a synchronous write of metadata to disk.
I'm running freebsd 7.2 with ZFS and have my data drives set to spin down when idle. They don't get re-spun back up all the time like you fear; only when there is a userland access. as mentioned elsewhere, the disks spin up sequentially which is a PITA. I had a little script on my previous linux box that spun up all the disks .5 second apart but i can't figure out how to get freebsd to tell me the current state of the disks. I don't know if the freebsd folks made any mods to ZFS for this but I kinda doubt it. I don't have anything spiffy like prefetching to a cache disk, etc. When I am streaming music to a squeezebox, all my disks are spinning. I have thought about hacking squeezecenter to copy to a temp disk but the win is pretty minimal, by the time they spin down i'll want them back to choose the next album. danno _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
