[CentOS] [HW] Do the HDD cages in rack mount chassis indicate visual/audio HDD failure?

Tue Oct 18 16:05:39 UTC 2011
Arun Khan <knura9 at gmail.com>

On Tue, Oct 18, 2011 at 8:55 PM, Karanbir Singh <mail-lists at karan.org> wrote:
> On 10/18/2011 04:11 PM, Arun Khan wrote:
>> You mean, it is not OK to pull out a "functioning" disk?  Pulling one
>> disk out of RAID 5 should be OK.  Am I missing something?
> grab yourself a bunch of usb keys +  a usb hub - fire up mdadm on your
> laptop and use those keys as target disks and see how things work with
> mdadm and hotswap. Much fun to be had there. I would also recommend
> using CentOS6.

Thanks for the suggestion - a great way to experiment.

>From the feedback on this thread, I am leaning towards h/w raid controller.

> Pulling a disk that isnt set bad and deactivated in mdadm can cause some
> very funky results - best of all, the machine will freeze and you can
> reinsert the disk boot up and carry on. Worst of all, you will lose all
> the data on the array.

I agree.

> btw, dont think that these issues dont affect hardware raid - they do.
> its just that the management for these things is slightly more
> abstracted away and the controllers are better integrated with the disk
> cages.

About 10 years ago, I had a h/w raid controller go bad (HDDs connected
via SCSI cable - no HDD bays involved).  The replacement card
recreated the RAID array - lost all data.  I did have a back up to
restore most of the data.

-- Arun Khan