[geeks] Shared Firewire Disk?

[Dan Duncan]

On 12/17/06, Mike Meredith <very at zonky.org> wrote:
> Just to be picky ... whilst you can't expect to mount a shared disk on
> two systems simultaneously using an ordinary filesystem, you can use a
> shared disk with systems taking turns to use it. For example, I once
> had an E450, an E3500 and an A1000 on the same SCSI bus. The E3500 ran
> the production database, once a day the E450 would shutdown the
> database on the E3500, cause the filesystem on the E3500 to unmount the
> shared disk, then mount it itself and copy the database elsewhere as a
> backup.

It depends on the systems, or at least the SCSI cards.  It won't work
on two Sparc Classics using the onboard SCSI controller.  First system
will boot, see the drives, load the OS, then when you boot the second
system it sends a SCSI bus reset which panics and reboots the first
system.  The second system comes up, at which point the first system
sends a SCSI bus reset...  I think you can do it some SBUS SCSI cards,
but we never could get it to work with the onboard controllers.