The difference between SCSI hard drives

Snapdragon · Unread post by **Snapdragon** » Tue Nov 14, 2006 8:12 pm

Just a quick question for those are in the know, I'm poking around google too but a human answer is always better

I'm about to buy a new server that has SAS, serial attached SCSI drives in it, and they appear to be the same as U320 SCSI, and I'm reading the throuput is supposed to be 146 MBps (I assume that's megaBYTES).

Are these drives the defacto standard now a days? I plan on putting 6 or 8 in another RAID 10. I currently run a 8 x 80 GB IDE RAID 10 and I love it, but I need to have enough expansion for the next 3-4 years (or however long this box takes to pay off!

)

So what is the deal with SCSI ratings, and is this more of a SATA II drive just worded differently, or is it true SCSI, or what?

PS I'm choosing the 73 GB 15K RPM models too... speed is good.

Unread post by **scott** » Wed Nov 15, 2006 11:48 am

You can look at disk performance with hdparm -t path_to_device. I'd check them out with that before you make any major investment in disks.

Snapdragon · Unread post by **Snapdragon** » Thu Nov 16, 2006 6:39 pm

Hmm, but being that they're both RAIDed, wouldn't that screw up the readings of individual disks?

They tell me that the SAS drives are 300 MB/sec on dedicated channels, one per drive, as opposed to U320 SCSI which is 320 MB/sec but shares the drives on the channel.. well, unless you have a nice fat SCSI card with lots of channels...

They use the SCA connector for hotswapping, which a few people have told me is the "best" hotswap package.

I can't really run any tests on the new equipment until I get it.. so dunno what to do there. I have to replace this server, and this seems to be the best cost/value.

Unread post by **scott** » Fri Nov 17, 2006 1:31 pm

Test them with that before you raid them.