Re: Sharing SCSI disks
Alan Cox (alan@lxorguk.ukuu.org.uk)
Wed, 19 Mar 1997 20:27:51 +0000 (GMT)
> Note that only ONE computer can have ACTUAL PHYSICAL access to the
> SCSI Disk. The other machines must have virtual access, which means
> that one machine only does the physical I/O. This can be explained
> as follows: Suppose you had two computers connected to the same SCSI
> drive. Suppose one of them went to read or write from the drive and
> found that the SCSI bus was busy. What would it do? It would reset
> the bus and retry. The other computer would then find that its
> I/O was aborted. It would then reset and retry. This would go on
> "forever" even if it was a read-only device!
On the contrary SCSI has full multi host/target arbitration - it depends
on your controller how happy it is but its fine, and sharing an ext2fs
disk Read only is just perfect