Thanks for your reply Miles. I think I understand your points, but unfortunately my historical knowledge of the the need for TLER etc solutions is lacking.
How I've understood it to be (as generic as possible, but possibly inaccurate as a result): 1. In simple non-RAID single drive 'desktop' PC scenarios where you have one drive, if your drive is experiencing read/write errors, as this is the only drive you have, and therefore you have no alternative redundant source of data to help with required reconstruction/recovery, you REALLY NEED your drive to try as much as possible to try to recover from the error, therefore a long 'deep recovery' process may be kicked off to try to fix/recover the problematic data being read/written. 2. Historically, hardware RAID arrays, where redundant data *IS* available, you really DON'T want any drive with trivial occasional block read errors to be kicked from the array, so the idea was to have drives experiencing read errors report quickly to the hardware RAID controller that there's a problem, so that the hardware RAID controller can then quickly reconstruct the missing data by using the redundant parity data. 3. With ZFS, I think you're saying that if, for example, there's a block read error, then even with a RAID EDITION (TLER) drive, you're still looking at a circa 7 second delay before the error is reported to ZFS, and if you're using a cheapo standard non-RAID edition drive then you're looking at a likely circa 60/70 second delay before ZFS is notified. Either way, you say that ZFS won't kick the drive, yes? And worst case is that depending on arbitrary 'unknowns' relating to the particular drive's firmware chemistry/storage stack, relating to the storage array's repsonsiveness, 'some time' could be 'mucho time' if you're unlucky. And to summarise, you don't see any point in spending a high premium on RAID-edition drives if using with ZFS, yes? And also, you don't think that using non-RAID edition drives presents a significant additional data loss risk? Cheers, Simon http://breden.org.uk/2009/05/01/home-fileserver-a-year-in-zfs/ -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
