external SATA disk array VS external SCSI disk array
Posted on 2004-09-23
I am setting up a two server cluster that will use an external storage array as shared direct attached storage. So there'll be two application servers sharing an external storage box. I want to purchase from one of the larger vendors (HP, IBM, Dell) so that I can get a high level of service on the hardware (with same day turnaround on failures). My data center will be in Chennai, India.
I'm currently looking at an IBM solution which would use the EXP 400 which is a direct attached shared SCSI storage disk array. It can take up to 14 drives. As i understand it - the largest SCSI drive is 150 GB - so this limits me to around 2 TB. Now we're goign to need a lot more than that over time.
What i want to know is:
a. is a direct attached SATA storage array an option? (with 250 GB per drive - that would at least increase the ceiling) Are there direct attached SATA arrays available from the mainstream vendors? as i said - i need the high SLA.
b. can a server have multiple SCSI storage arrays attached to it? i.e. if my application servers had two raid controllers, could they be attached to two external SCSI arrays? thereby doubling the storage available to my cluster?
c. would SATA be a bad choice because of lower througput than SCSI and lower disk speeds than SCSI?