Re: Recover SCSI disks

[Douglas Gilbert <dougg@torque.net>]

Robin Bowes wrote:
> Hi,
> 
> I've got a Compaq U2 storage array connected to a Compaw Smart 2/p
> controller with an assortment of 4.3GB and 9.1GB disks that I use for
> testing purposes.
> 
> Some of the drives have "died" on me, i.e. I get yellow lights when they
> are plugged into the arrays.
> 
> Is it possible to do anything low-level to ressurect these drives? e.g.
> take them out of their caddies, connected them directly to a SCSI
> controller and low-level format them or something?
> 
> (There's no data on them - I just want them to work again!)
> 
> Any suggestions appreciated.

Robin,
You may like to fetch sg3_utils and try sg_format thus:
   sg_format /dev/sda
assuming a disk you have fetched from the array is placed
at /dev/sda .

If that fails, the disk is probably dead. Otherwise it
should tell you several things (and doesn't change
anything). Often drives in RAIDs are formatted
to a sector size slightly greater than 512 bytes. To
re-use the disk (freestanding) in linux you will need to
format it back 512 bytes thus:
   sg_format --format --size=512 /dev/sda

A format may not be needed. In any case, the next step
would usually be to partition the disk (e.g. with fdisk)
then make a file system on one or more of its partitions
(e.g. with mkfs.ext3 ). The disk (or at least its partition)
should then be ready to mount and use.

Doug Gilbert