[OpenIndiana-discuss] [illumos-Developer] ZFS spare disk usage issue

[Jonathan Adams]

http://bugs.illumos.org/ works for me from here.

We're always delicate with our ZFS systems ... we've been trialling
ZFS raid over USB for quite a while, since early ZFS days, and we were
never sure if it was the USB or the ZFS ...

If you remove all your ZFS drives, reboot, export, "devfsadm -C" and
then carefully import drives into your array, not too many at once you
can usually get the system back, but that could just have been down to
not enough memory, or use of external USB devices.

how much memory do you have in your computers?

On 4 March 2011 17:03, Roy Sigurd Karlsbakk <roy at karlsbakk.net> wrote:
> So should I post a bug, or is there one there already?
>
> Btw, I can't reach http://bugs.illumos.org/ - it times out
>
> roy
>
> ----- Original Message -----
>> We've talked about this, and I will be putting together a fix for this
>> incorrect state handling. :-)
>>
>> - Garrett
>>
>> On Fri, 2011-03-04 at 11:50 -0500, Eric Schrock wrote:
>> > This looks like a pretty simple bug. The issue is that the state of
>> > the SPARE vdev is being reported as REMOVED instead of DEGRADED. If
>> > it were the latter (as it should be), then everything would work
>> > just
>> > fine. Please file a bug at bugs.illumos.org.
>> >
>> >
>> > On a side note, this continues to expose the overly simplistic vdev
>> > state model used by ZFS (one which I can take a bulk of the
>> > responsibility for). Back before the days of ditto blocks and
>> > SPA3.0,
>> > it was sufficient to model state as a fairly binary proposition. But
>> > this now has ramifications that don't necessarily make sense. For
>> > example, one may be able open a pool even if a toplevel vdev is
>> > faulted. And even when a spare has finished resilvering, it's left
>> > in
>> > the DEGRADED state, which has implications for allocation policies
>> > (though I remember discussions around changing this). But the pool
>> > state is derived directly from the toplevel vdev state, so if you
>> > switch spares to be ONLINE, then 'zpool status' would think your
>> > pool
>> > is perfectly healthy. In this case it's true from a data protection
>> > standpoint, but not necessarily from a "all is well in the world"
>> > standpoint, as you are down one spare, and that spare may not have
>> > the
>> > same RAS properties as other devices in your RAID-Z stripe (it may
>> > put
>> > 3 disks on the same controller in one stripe, for example).
>> >
>> >
>> > - Eric
>> >
>> > On Fri, Mar 4, 2011 at 7:06 AM, Roy Sigurd Karlsbakk
>> > <roy at karlsbakk.net> wrote:
>> >         Hi all
>> >
>> >         I just did a small test on RAIDz2 to check whether my
>> >         suspicion was right about ZFS not treating spares as
>> >         replicas/copies of drives, and I think I've found it true.
>> >         The
>> >         short story: If two spares replaces two drives in raidz2,
>> >         losing a third drive, even with the spares active, makes the
>> >         pool unavailable. See full report on
>> >
>> >         ODT: http://karlsbakk.net/ZFS/ZFS%20Spare%20disk%20usage.odt
>> >         PDF: http://karlsbakk.net/ZFS/ZFS%20Spare%20disk%20usage.pdf
>> >
>> >         Vennlige hilsener / Best regards
>> >
>> >         roy
>> >         --
>> >         Roy Sigurd Karlsbakk
>> >         (+47) 97542685
>> >         roy at karlsbakk.net
>> >         http://blogg.karlsbakk.net/
>> >         --
>> >         I all pedagogikk er det essensielt at pensum presenteres
>> >         intelligibelt. Det er et elementært imperativ for alle
>> >         pedagoger å unngå eksessiv anvendelse av idiomer med fremmed
>> >         opprinnelse. I de fleste tilfeller eksisterer adekvate og
>> >         relevante synonymer på norsk.
>> >
>> >         _______________________________________________
>> >         Developer mailing list
>> >         Developer at lists.illumos.org
>> >         http://lists.illumos.org/m/listinfo/developer
>> >
>> >
>> >
>> > --
>> > Eric Schrock
>> > Delphix
>> >
>> >
>> > 275 Middlefield Road, Suite 50
>> > Menlo Park, CA 94025
>> > http://www.delphix.com
>> >
>> >
>> > _______________________________________________
>> > Developer mailing list
>> > Developer at lists.illumos.org
>> > http://lists.illumos.org/m/listinfo/developer
>
> --
> Vennlige hilsener / Best regards
>
> roy
> --
> Roy Sigurd Karlsbakk
> (+47) 97542685
> roy at karlsbakk.net
> http://blogg.karlsbakk.net/
> --
> I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk.
>
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