Re: Newbie scsi question

["Chuck Tuffli" <ctuffli@xxxxxxxxx>]

On 5/3/06, Karthik Subramanian <karthik301176@xxxxxxxxx> wrote:
. ..
> Here's the problem:
> ----------------------------
> Consider a typical SAN setup - an FC switch with a couple of JBOD's
> and a couple of machines hooked up to the switch.
>
> On linux, the disks from the JBOD are recognised as /dev/sd[a-n]. The
> hitch is that the device naming is not consistent across reboots; the
> first time around, /dev/sdb could refer to the first disk on the JBOD.
> The second time around, you don't know what it points to, as the
> assignment of device names to disks depends on the order in which the
> disks are recognised at boot time. Of course, there are fixes to this
> problem - like devlabel/udev, but they are essentially fixes to a
> problem that should never have been there in the first place.
. ..
> In this kind of a situation, what does DragonFly do to ensure that the
> disk names are consistent across reboots?

Unfortunately, DragonFly (and most of the other *BSDs I think) doesn't
have a good answer for persistent binding. You can setup the kernel to
"wire down" a particular bus/target/lun to a specific device, but I
don't think this would work for SANs.

---chuck