Re: RAID vs. Single Big SCSI Disk

"G. Anthony Reina" wrote:

> We have three databases for our scientific research and are getting
> close to filling our 12 Gig partition. My boss thinks that just getting
> a really big (i.e. > 30 Gig) SCSI drive will be cheaper and should do
> nicely. Currently, we only have 4 people accessing the database and
> usually only have 1-2 jobs (e.g. selects, updates, etc.) going at any
> one time (probably a high estimate). The db sits on a Pentium II/400 MHz
> with RedHat 6.0.
>
> Other than mirroring, are there any other advantages (e.g. speed, cost)
> of just getting a RAID controller over, say, a 73 Gig Ultra SCSI Cheetah
> drive (which cost in the neighborhood of $1300).

It sounds like you would be much better off with an Ultra ATA 66
software or hardware RAID solution. Maxtor 40 Gb ATA100 disks
can be had for $100. each. Alone they operate near 20 Mb/sec
and in a striped 2 disk Raid they can do 30-40 Mb/sec, probably
faster than your Cheetah configuration for a fraction of the cost.
3ware makes a hardware RAID controller that would get you to
40 Mb/sec with two, or 70 mb/sec with four of these disks in RAID 0.
With four disks in RAID 01 you can mirror and still get near 40 Mb/sec.
The 3ware solution also relieves your cpu from the usual ATA overhead.

>
>
> Also, can Postgres handle being spread over several disks? I'd think
> that the RAID must control disk spanning, but just want to make sure
> that Postgres would be compatible.

That is transparent.