i have a Dell Precision 670 server with SCSI disk drives, i have a 74 gb disk and I want to add another 74 gb to make disk mirroring. Any suggestions. I am using it for ubuntu 8.04
Well, Your rig has SATA, think about balancing the cost of one U320 SCSI disk against two or three big SATA disks in three way mirror. There should not be too much performance difference (High rpm Drives, which performance scsi drives usually are, have shorter access times though, so usually more iops.). The sata drives might even be faster if more than two sata drives can be used. Are You looking for performance or data security?
It would be interesting to know what scsi hdd model is in Your pc at the moment.
The cheapest U320 scsi disk at 74 GB around my country is the Toshiba Allegro 10, 73.5GB (MBA3073NP) at 147 Euros plus shipping. You get 3 Samsung SpinPoint T166 250GB, 16MB Cache, SATA II (HD252KJ) for 100 euros. 3 Seagate 7200.12 or hitachi deskstars go at about 35 Euros a piece. So I don't know if the single scsi disk is worth it. You could even go for a 4 way mirror or a real raid configuration.
Considering fast 15000 rpm scsi drives, which we are talking here, the main benefit is the faster access times.
Also, Ubuntu should support software raid/mirroring, so no problem there.
Edit have a lookm at Your mainboard, from the dell specs it looks like it has only 2 SATA connectors, but I am not sure. 2 Sata connectors mean that there can only be simple mirroring on SATA, no triple or 4 way mirroring and also no real raid (on sata)
What do the other commenters think?