[CentOS] iSCSI disk preperation

Mon Feb 7 20:26:48 UTC 2011
Ross Walker <rswwalker at gmail.com>

On Mon, Feb 7, 2011 at 1:56 PM, Jason Brown
<jason.brown at millbrookprinting.com> wrote:
> I am currently going through the process of installing/configuring an
> iSCSI target and cannot find a good write up on how to prepare the disks
> on the server.  I would like to mirror the two disks and present them to
> the client.  Mirroring isn't the question, its how I go about it is the
> problem.  When I partitioned the two drives and mirrored them together,
> then presented them to the client, it showed to the client as a disk out
> no partion on it.  Should I partition the drive again and then lay the
> file system down on top of that?  Or should I delete the partitions on
> the target server and just have sda and sdb mirrored, then when the
> client attaches the disk, then partion it (/dev/sdc1) and write the file
> system.

Whatever you export, the whole disk, partition or logical volume, the
initiator will see as a whole disk.

So if you mirror sdaX and sdbX and export md0 the initiator will see a
disk the size and contents of sdaX/sdbX.

Just create the filesystem on the disk on the initiator and use it there.

REMEMBER: iSCSI isn't a way for multiple initiators to share the same
disk (though they can using specialized clustering file systems), it
is a way for multiple initiators to share the same disk subsystem.

You can't access the file system from both the target-side and
initiator-side at once or it will corrupt the file system. If that's
what you want then you want NFS or Samba and not iSCSI.