ZFS w/failing drives - any equivalent of Solaris FMA?

[Zaphod Beeblebrox]

On Fri, Sep 12, 2008 at 12:32 PM, Jeremy Chadwick <koitsu at freebsd.org>wrote:

> On Fri, Sep 12, 2008 at 12:04:27PM -0400, Zaphod Beeblebrox wrote:
> > On Fri, Sep 12, 2008 at 11:44 AM, Oliver Fromme <olli at lurza.secnetix.de
> >wrote:
> > > Did you try "atacontrol detach" to remove the disk from
> > > the bus?  I haven't tried that with ZFS, but gmirror
> > > automatically detects when a disk has gone away, and
> > > doesn't try to do anything with it anymore.  It certainly
> > > should not hang the machine.  After all, what's the
> > > purpose of a RAID when you have to reboot upon drive
> > > failure.  ;-)
> >
> > To be fair, many "home" users run RAID without the expectation of being
> able
> > to hot swap the drives.  While RAID can provide high availability, but it
> > can also provide simple data security.
>
> RAID only ensures a very, very tiny part of "data security", and it
> depends greatly on what RAID implementation you use.  No RAID
> implementation I know of provides against transparent data corruption
> ("bit-rot"), and many RAID controllers and RAID drivers have bugs that


Well... this is/was a thread about ZFS.  ZFS does detect that bitrot _and_
correct it if it is possible.


> A big problem is also that end-users *still* think RAID is a replacement
> for doing backups


Well... this comment seems a bit off topic, but maybe (in some cases) RAID
is a substitute for doing backups.  I suppose it depends on your tolerance
and data value.  The sheer size of some datasets these days makes backup
prohibitively time consuming and/or expensive.  Then again (this is a ZFS
thread), ZFS helps with this: the ability to export snapshots to other
spinning spool makes a lot of sense.