[176756] in North American Network Operators' Group
Re: Got a call at 4am - RAID Gurus Please Read
daemon@ATHENA.MIT.EDU (Bacon Zombie)
Thu Dec 11 11:09:30 2014
X-Original-To: nanog@nanog.org
In-Reply-To: <CA+M5dWa+nXWOcn7D53UeerYgfGigrr_=oQ+Q1sYMjcLwieR9uQ@mail.gmail.com>
Date: Thu, 11 Dec 2014 17:06:25 +0100
From: Bacon Zombie <baconzombie@gmail.com>
To: Javier J <javier@advancedmachines.us>
Cc: Rob Seastrom <rs@seastrom.com>, nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
Are you running ZFS and RAIDZ on Linux or BSD?
On 10 Dec 2014 23:21, "Javier J" <javier@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@seastrom.com> wrote:
>
> >
> > The subject is drifting a bit but I'm going with the flow here:
> >
> > Seth Mos <seth.mos@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
> >
> >
>
