Author: Ward Vandewege Date: To: exim-users Subject: Re: [exim] [OT] RAID (was: Re: Which hardware do you use for
yourinstallation?)
On Thu, Jun 12, 2008 at 10:41:35AM +0200, Sander Smeenk wrote: > Quoting Nigel Metheringham (nigel.metheringham@???):
>
> > I have to say I am getting less convinced by RAID 1 on systems.
>
> RAID at all for me, actually. I've seen it crumble down to a grinding
> halt several times (using software raid, mdadm, that is). While it was
> designed so that a disk could fail without the service being
> interrupted, in my experience a disk failing will still make the system
> unusable. Either because the kernel goes haywire trying to adress the
> non-working device
I used to see this with IDE drives, but have not seen this in the past couple
years with sata drives. I think this problem might be history.
> or mdadm making decisions causing the entire set to
> go offline.
>
> Especially mdadm setups where you combine RAID-0 and RAID-1 sets to
> achieve RAID-10 tend to break when there's problems.
>
> Still, recovery is easier as the set can rebuild or data can be
> retrieved from just one disk from a set...
Yeah. Rebuilding a raid-1 array also seems to put much less stress on the
surviving drives than rebuilding a raid-5 or 6 array. I've seen multiple
disks die during reconstruction of a raid-5 or 6 array on several unhappy
occasions.