Date: Fri, 12 Sep 2008 12:47:21 -0400 From: "Zaphod Beeblebrox" <zbeeble@gmail.com> To: "Jeremy Chadwick" <koitsu@freebsd.org> Cc: freebsd-hackers@freebsd.org, kpielorz_lst@tdx.co.uk Subject: Re: ZFS w/failing drives - any equivalent of Solaris FMA? Message-ID: <5f67a8c40809120947u2bbeb03cnb20618e1d9ddf6b8@mail.gmail.com> In-Reply-To: <20080912163207.GE60094@icarus.home.lan> References: <C984A6E7B1C6657CD8C4F79E@Slim64.dmpriest.net.uk> <200809121544.m8CFiRHQ099725@lurza.secnetix.de> <5f67a8c40809120904o49b6e410l5b65a20f5216202@mail.gmail.com> <20080912163207.GE60094@icarus.home.lan>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Sep 12, 2008 at 12:32 PM, Jeremy Chadwick <koitsu@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@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.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5f67a8c40809120947u2bbeb03cnb20618e1d9ddf6b8>