Got a call at 4am - RAID Gurus Please Read

Bacon Zombie baconzombie at gmail.com
Thu Dec 11 16:06:25 UTC 2014


Are you running ZFS and RAIDZ on Linux or BSD?
On 10 Dec 2014 23:21, "Javier J" <javier at advancedmachines.us> wrote:

> I'm just going to chime in here since I recently had to deal with bit-rot
> affecting a 6TB linux raid5 setup using mdadm (6x 1TB disks)
>
> We couldn't rebuild because of 5 URE sectors on one of the other disks in
> the array after a power / ups issue rebooted our storage box.
>
> We are now using ZFS RAIDZ and the question I ask myself is, why wasn't I
> using ZFS years ago?
>
> +1 for ZFS and RAIDZ
>
>
>
> On Wed, Dec 10, 2014 at 8:40 AM, Rob Seastrom <rs at seastrom.com> wrote:
>
> >
> > The subject is drifting a bit but I'm going with the flow here:
> >
> > Seth Mos <seth.mos at dds.nl> writes:
> >
> > > Raid10 is the only valid raid format these days. With the disks as big
> > > as they get these days it's possible for silent corruption.
> >
> > How do you detect it?  A man with two watches is never sure what time it
> > is.
> >
> > Unless you have a filesystem that detects and corrects silent
> > corruption, you're still hosed, you just don't know it yet.  RAID10
> > between the disks in and of itself doesn't help.
> >
> > > And with 4TB+ disks that is a real thing.  Raid 6 is ok, if you accept
> > > rebuilds that take a week, literally. Although the rebuild rate on our
> > > 11 disk raid 6 SSD array (2TB) is less then a day.
> >
> > I did a rebuild on a RAIDZ2 vdev recently (made out of 4tb WD reds).
> > It took nowhere near a day let alone a week.  Theoretically takes 8-11
> > hours if the vdev is completely full, proportionately less if it's
> > not, and I was at about 2/3 in use.
> >
> > -r
> >
> >
>



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