Date: Mon, 04 Jun 2012 22:48:00 +0200 From: Johan Hendriks <joh.hendriks@gmail.com> To: Kaya Saman <kayasaman@gmail.com> Cc: freebsd-fs@freebsd.org Subject: Re: Using ZFS as RAID0 - disk offline question Message-ID: <4FCD1F00.5080805@gmail.com> In-Reply-To: <4FCD19E6.1010802@gmail.com> References: <4FCD13CF.3010406@gmail.com> <4FCD17C6.5020503@FreeBSD.org> <4FCD19E6.1010802@gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Kaya Saman schreef: > On 06/04/2012 09:17 PM, Matthew Seaman wrote: >> On 04/06/2012 21:00, Kaya Saman wrote: >>> in ZFS when using a simple RAID 0 style array is there a way to recover >>> a pool after a disk has gone down? >> No. RAID0 has no resilience to disk failure. That's why things like >> RAID1, RAID10, RAIDz, RAIDz2 exist: so that your data will survive >> failure of some number of the drives it is stored on. >> >> Make sure you have good backups, basically. >> >> Cheers >> >> Matthew >> > > Thanks for the responses! > > > I wasn't actually meaning recovering data on the 'downed' disk but on > the disk that was still online...... > > > You see if say a system board fails and both devices are named > /dev/ad4 and /dev/ad5 then a new system board gets put in and the > device names changed to /dev/ad12 and /dev/ad13 my question is will > the ZPOOL still exist? Will ZFS be intelligent enough to pick up the > new device names via the disk ID's? > > > Additionally if /dev/ad5 goes down, is it possible to keep using > /dev/ad4 which is part of the 'downed' pool...?? Or would one need to > replace the disk ad5 then the pool comes up again with only the > information on ad4?? > > > This is what I was trying to get at and sorry if I didn't understand > 100% the direction of the responses! > > As in if you meant that the information of on /dev/ad5 will be lost - > I do understand this :-) > > > Regards, > > Kaya > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" you can not loose a disk from a raid0 period. To put it simple, your files are split in half, one part is copied to disk 1 and the other part on disk2 . So without the two copies no files, no data. If device names changes because of a hardware change, the pool schould be importable. But both disks need to be there. Raid0 should be avoided if possible, better add one disk extra and create a raidz. regards Johan Hendriks
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4FCD1F00.5080805>