benefit of GEOM labels for ZFS, was Hard drive device names... serial numbers

[Peter Maloney]

I just use zfs offline, then dd to read the disk, and pull the one that
blinks. :) zfs offline means the disk won't blink ever without me
causing it, so there's no confusion.

I would only use a labelling system if I could easily label the disks on
the front too, but I don't have small enough labels... the disks have
too much vent space, so I assume the labels would just fall off, block
airflow, and be a hassle. And the servers are local, so dd isn't a problem.



On 2013-03-01 00:25, Graham Allan wrote:
> Sorry to come in late on this thread but I've been struggling with
> thinking about the same issue, from a different perspective.
>
> Several months ago we created our first "large" ZFS storage system,
> using 42 drives plus a few SSDs in one of the oft-used Supermicro
> 45-drive chassis. It has been working really nicely but has led to
> some puzzling over the best way to do some things when we build more.
>
> We made our pool using geom drive labels. Ever since, I've been
> wondering if this really gives any advantage - at least for this type
> of system. If you need to replace a drive, you don't really know which
> enclosure slot any given da device is, and so our answer has been to
> dig around using sg3_utils commands wrapped in a bit of perl, to try
> and correlate the da device to the slot via the drive serial number.
>
> At this point, having a geom label just seems like an extra bit of
> indirection to increase my confusion :-) Although setting the geom
> label to the drive serial number might be a serious improvement...
>
> We're about to add a couple more of these shelves to the system,
> giving a total of 135 drives (although each shelf would be a separate
> pool), and given that they will be standard consumer grade drives,
> some frequency of replacement is a given.
>
> Does anyone have any good tips on how to manage a large number of
> drives in a zfs pool like this?
>
> Thanks,
>
> Graham


-- 

--------------------------------------------
Peter Maloney
Brockmann Consult
Max-Planck-Str. 2
21502 Geesthacht
Germany
Tel: +49 4152 889 300
Fax: +49 4152 889 333
E-mail: peter.maloney at brockmann-consult.de
Internet: http://www.brockmann-consult.de
--------------------------------------------