scsi raid

[Texasscreen]

Trying to put together a 0+1 RAID array on my Mac G4, using a 39160 card. (Way over my head, really, but I think that I can do it.) I've got
two Compaq 15K 18.2 G drives on the card right now. (using Mac OS X to create a RAID 1 volume striping the two channels.) I want to add two 18.2G drives for redundancy. My question is how closely do these additional drives have to "match" the two that I'm using (these are same model.) Will other models of 18.2G 15K drives work OK? And will U320 drives work or do they have to be 160's? Thanks!

 

[Mercutio]

As you are doing RAID in software, as long as the drives in each RAID0 set are the same make and model, I think you'll be fine.

Sometimes I mix and match IDE and SATA (say, Samsung 160GB drives which have both PATA and SATA versions, or Hitachi 7k250s) drives on Windows or Linux software RAID sets, and I can't say it's ever caused any particular problems for me.

Getting identical drives is a much, much more important factor in making hardware-based arrays work properly, and most especially for bringing a replacement drive into a failed-redundancy RAID5 array. As long as the volume sizes can be at least the same on your software array (that can be a problem, as Seagate's 18GB drive is a little tiny bit bigger than say, Fujitsu's), the worst thing that might happen is sub-optimal performance with one drive being somewhat slower than the other(s).

U320 drives will work on a U160 controller. With four X15s, the fact that your controller is sitting in a PCI slot is going to be your biggest bottleneck anyway.

 

[Texasscreen]

Thanks. I obviously chose the right forum to post my question in.