Help on SCSI Disk conf. on SA642 with disks USCSI3 and USCSI320

[Paulo_28]

Hi,


I have 2 set of disks in a cage connected to a smart array 642. the first set are 2 Raid1 disks of 18G UltraSCSI3 (i think they work at 160M)and 4 Raid5 disks of 72G UltraSCSI320 (I think they work at 320M). What I ask is if they work all at 160M or work at 160M the 2 disks in raid1 and at 320M the 4 disk in raid5?

Thanks,

Paulo Meireles

[Ron Lawson_1]

The data transfer rate between a SCSI initiator and a SCSI target are negotiated independently of other initiators or targets on the bus.

Assuming all of the SCSI bus hardware supports the U320 rate, you should get U320 speeds on the RAID 5 array.

[Paulo_28]

thanks,

but the problem is that I need to use the 2 18 HD SCSI in Raid1 and the other 4 72 HD SCSI320 in the same cage. I didn't understand quit well what you write, can you please clarify if the HD will work at their speed? the 2 raid1 SCSI3 at 160M and the other 4 SCSI320 hdin Raid5 at 320M? inspite they are in the same cage but in diferent raid configurantions. Is the size a problem? I know that in the same raid the hd must be the same size but what I have 2 groups with diferent speeds and sizes in the same cage connected to the SA642.

Thanks again,

Paulo Meireles

[JohnWRuffo]

Q1. Are the Smart Array 641/642 U320 controllers backwards compatible to Ultra 2 and Ultra 3 SCSI?
A1. Ultra320 technology is backward compatible to Ultra3 and Ultra2. When mixing and matching different interface speeds, the Ultra320 products will operate at the lowest speed in the system. For example, when mixing U320 and U3 drives in an external array with a U3 controller, all drives will operate at the Ultra3 speed of the controller. To attain maximum transfer rates of up to 320 MB/s with U320 technology all components must be Ultra320 capable - the drives, the controller or SCSI adapter, and, if external to the server, the enclosure I/O modules as well.