zfs discuss - Mar 2011 - Any use for extra drives?

Hi ladies and gents, I''ve got a new Solaris 10 development box with ZFS
mirror root using 500G drives. I''ve got several extra 320G drives and
I''m
wondering if there''s any way I can use these to good advantage in this
box. I''ve got enough storage for my needs with the 500G pool. At this
point
I would be looking for a way to speed things up if possible or add
redundancy if necessary but I understand I can''t use these smaller
drives to
stripe the root pool, so what would you suggest? Thanks.

> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss-
> bounces at opensolaris.org] On Behalf Of Nomen Nescio
> 
> Hi ladies and gents, I''ve got a new Solaris 10 development box
with ZFS
> mirror root using 500G drives. I''ve got several extra 320G drives
and I''m
> wondering if there''s any way I can use these to good advantage in
this
> box. I''ve got enough storage for my needs with the 500G pool. At
this
point
> I would be looking for a way to speed things up if possible or add
> redundancy if necessary but I understand I can''t use these smaller
drives
to
> stripe the root pool, so what would you suggest? Thanks.
Generally, you choose your data pool config based on data size, redundancy,
and performance requirements.  If those are all satisfied with your single
mirror, the only thing left for you to do is think about splitting your data
off onto a separate pool due to better performance etc.  (Because there are
things you can''t do with the root pool, such as striping and raidz)

That''s all there is to it.  To split, or not to split.

> Generally, you choose your data pool config based on data size,
> redundancy, and performance requirements.  If those are all satisfied with
> your single mirror, the only thing left for you to do is think about
> splitting your data off onto a separate pool due to better performance
> etc.  (Because there are things you can''t do with the root pool,
such as
> striping and raidz) 
> 
> That''s all there is to it.  To split, or not to split.
Thanks for the update. I guess there''s not much to do for this box
since
it''s a development machine and doesn''t have much need for
extra redundancy
although if I would have had some extra 500s I would have liked to stripe
the root pool. I see from your answer that''s not possible anyway.
Cheers.

On Mar 24, 2011, at 5:42 AM, Edward Ned Harvey wrote:
>> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss-
>> bounces at opensolaris.org] On Behalf Of Nomen Nescio
>> 
>> Hi ladies and gents, I''ve got a new Solaris 10 development box
with ZFS
>> mirror root using 500G drives. I''ve got several extra 320G
drives and I''m
>> wondering if there''s any way I can use these to good advantage
in this
>> box. I''ve got enough storage for my needs with the 500G pool.
At this
> point
>> I would be looking for a way to speed things up if possible or add
>> redundancy if necessary but I understand I can''t use these
smaller drives
> to
>> stripe the root pool, so what would you suggest? Thanks.
> 
> Generally, you choose your data pool config based on data size, redundancy,
> and performance requirements.  If those are all satisfied with your single
> mirror, the only thing left for you to do is think about splitting your
data
> off onto a separate pool due to better performance etc.  (Because there are
> things you can''t do with the root pool, such as striping and
raidz)
> 
> That''s all there is to it.  To split, or not to split.
I''d just put /export/home on this second set of drives, as a striped
mirror.

Same as I would have done in the "old days" under SDS. :-)

Mark

On Mar 24, 2011, at 7:23 AM, Anonymous wrote:
>> Generally, you choose your data pool config based on data size,
>> redundancy, and performance requirements.  If those are all satisfied
with
>> your single mirror, the only thing left for you to do is think about
>> splitting your data off onto a separate pool due to better performance
>> etc.  (Because there are things you can''t do with the root
pool, such as
>> striping and raidz) 
>> 
>> That''s all there is to it.  To split, or not to split.
> 
> Thanks for the update. I guess there''s not much to do for this box
since
> it''s a development machine and doesn''t have much need for
extra redundancy
> although if I would have had some extra 500s I would have liked to stripe
> the root pool. I see from your answer that''s not possible anyway.
Cheers.
If you plan to generate a lot of data, why use the root pool? You can put the
/home
and /proj filesystems (/export/...) on a separate pool, thus off-loading the
root pool.

My two cents,
Mark

Right, put some small (30GB or something trivial) disks in for root and 
then make a nice fast multi-spindle pool for your data.  If your 320s 
are around the same performance as your 500s, you could stripe and 
mirror them all into a big pool.  ZFS will waste the extra 180 on the 
bigger disks but that''s fine because your pool will bigger and faster 
anyway.

On 03/25/11 09:18, Mark Sandrock wrote:
>
> On Mar 24, 2011, at 7:23 AM, Anonymous wrote:
>
>>> Generally, you choose your data pool config based on data size,
>>> redundancy, and performance requirements.  If those are all
satisfied with
>>> your single mirror, the only thing left for you to do is think
about
>>> splitting your data off onto a separate pool due to better
performance
>>> etc.  (Because there are things you can''t do with the root
pool, such as
>>> striping and raidz)
>>>
>>> That''s all there is to it.  To split, or not to split.
>>
>> Thanks for the update. I guess there''s not much to do for this
box since
>> it''s a development machine and doesn''t have much need
for extra redundancy
>> although if I would have had some extra 500s I would have liked to
stripe
>> the root pool. I see from your answer that''s not possible
anyway. Cheers.
>
> If you plan to generate a lot of data, why use the root pool? You can put
the /home
> and /proj filesystems (/export/...) on a separate pool, thus off-loading
the root pool.
>
> My two cents,
> Mark
>
>
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> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

> Right, put some small (30GB or something trivial) disks in for root
> and
> then make a nice fast multi-spindle pool for your data. If your 320s
> are around the same performance as your 500s, you could stripe and
> mirror them all into a big pool. ZFS will waste the extra 180 on the
> bigger disks but that''s fine because your pool will bigger and
faster
> anyway.
Actually, it won''t. With two 500GB drives, it''ll create a
500GB mirror even if you add that to a pool with 320GB mirrors. That way you
will end up with a somewhat badly balanced pool, so once the 320GB mirrors are
filled up, only the 500GB mirrors will be used. You can work around this by
using partitions, but generally it''s preferred to use drives same size
and not partitions at all (IIRC ZFS turns off write cache by default when
talking to a partition device, but then, don''t shoot me if I''m
wrong).

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
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relevante synonymer p? norsk.

> If you plan to generate a lot of data, why use the root pool? You can put
> the /home and /proj filesystems (/export/...) on a separate pool, thus
> off-loading the root pool.
I don''t, it''s a development box with not alot happening.
> 
> My two cents,
thanks

> Right, put some small (30GB or something trivial) disks in for root and 
> then make a nice fast multi-spindle pool for your data.  If your 320s 
> are around the same performance as your 500s, you could stripe and 
> mirror them all into a big pool.  ZFS will waste the extra 180 on the 
> bigger disks but that''s fine because your pool will bigger and
faster
> anyway.
Yes if I had the disks earlier your idea sounds like a good one.
Unfortunately I only got the drives after I parted out several old boxes for
some friends. Thanks for your suggestions

Thanks Roy and everyone that answered. Sorry if the replies arrive out of
order and late.