Hi, I'm copying the list - assume you meant to send it there. On Sun 2010-12-19 (15:52), Miles Nordin wrote: > If 'zpool replace /dev/ad6' will not accept that the disk is a > replacement, then You can unplug the disk, erase the label in a > different machine using > > dd if=/dev/zero of=/dev/thedisk bs=512 count=XXX > dd if=/dev/zero of=/dev/thedisk bs=512 count=XXX seek=YYY > > then plug it back into its old spot and issue 'zpool replace /dev/ad6' > > XXX should be about a mbyte worth of sectors, and YYY should be the > LBA of about 1mbyte from the end of the disk. You can read or > experiment to determine the exact values. you do need to know the > size of your disk in sectors though. There's a copy of the EFI label > at the end of the disk and another at the beginning, which is why you > have to do this.
Awesome, that does the trick thanx. I assumed it was identifying the disk by serial number or something. I don't need to unplug the disk though, it works if I zero it from the same machine. This should probably be implemented as a zpool function, if it hasn't already been in later versions. > In general especially when a disk has corrupt data on it rather than > unreadable sectors it's best to do the replacement in a way that the > old and new disks are available simultaneously, because ZFS will use > the old disk sometimes in places where the old disk is correct. If > you take away the old disk, then the old disk can't be used at all > even when it's correct, so if there are a few spots where there are > problems with the other good disks in the raidz you will not be able > to recover that, while with a suspect old disk you could. OTOH if the > old disk has unreadable sectors, the controller and ZFS will freeze > whenever it touches those unreadable sectors, causing the replacement > to take forever. This is kind of bullshit and should be solved with > software IMNSHO, but it's how things are, so if you have a physically > failing disk I would suggest running the replace/resilver with the > physically failing disk physically removed (while if the disk has bad > data on it and is not physically failing i suggest keeping it > ocnnected somehow). so...yeah...if there is corrupt data on this > disk, you'll have to buy another disk to follow my advice in this > paragraph. you can go ahead and break the advice, wipe the label, > replace, though. Noted. Though if "there are a few spots where there are problems with the other good disks" ZFS should know about them right? _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
