A1000 SCSI questions

[Andreas Sindermann]

Stuart Remphrey writes:
 > Sorry, you can't treat an A1000 as a D1000. The D1000 has two internal
 > SCSI busses which can be either joined or brought to the outside
 > separately. The A1000 has a RAID controller which has only one host
 > SCSI bus (with IN and OUT connections). AFAIK it's only supported to use

Ok, that's exactly what I thought, thanks.

[...]
 > You can use DiskSuite or SEVM/VxVM on top of the A1000 on-board RAID,
 > but this doesn't solve the single bus issue.

Ah, a second interesting question is coming to my mind. The VM manual
says that striping above mirroring helps to improve recovery time
after a disk fault (the stripes need to be large enough so more than
one subdisk is being used in one stripe, in effect the subdisks
themselves will be mirrored, thus being recovered instead of the
complete mirror).

But it seems to me that this concept cannot be implemented using the
A1000 hardware raid feature (rm6). It has to be done by using VM
exclusively which means that the valuable Cache Memory of the A1000
arrays cannot be used. Is this correct?

Andreas