[rescue] StorEdge Multipack 711 questions

[Mike Spooner]

Care needed with the 12-slot model. The 12-slot internal SCSI backplane is only qualified for Fast-SCSI signalling speed. If you equip that with Ultra-SCSI drives and connect it to an Ultra-SCSI-capable host adaptor (eg: the builtin SCSI in the Ultra-2 workstation and Enterprise 250 and others, or  https://fido.aalin.co.uk/vault/hw/system/sun/sbus-se-uws/), the OS will negotiate with the drives for transmission speed and select Ultra-SCSI, not being able to notice that that particular 711 *backplane* is not rated for that speed; the result being likely data-corruption. Sun issued a product notice about that issue, after some customers experienced exactly that data-corruption problem. The "fix" is to either disable Ultra-SCSI capability on the host adaptor concerned (on Solaris via a setting in /etc/hosts), or by not using Ultra-SCSI-capable drives in the enclosure.

The 6-slot internal backplane in those 711 enclosures equipped with it, do not suffer the same problem, as that backplane is fully qualified for Ultra-SCSI signalling speed.

-- Mike