Re: Cheap RAID system recommendation?

Anthony Mandic <am_is_not_at_start.com.au> wrote:

> You could lease a system rather than buy. You could also trade in
> the A1000.

Exactly. We are considering leasing instead.

>> - disks with 15000 RPM for small latency
>
> Hmmm ... if you go with 10K RPM ones it would bring the costs
> down.

No compromise here.

>> - 400 GB capacity total, equivalent to 200 GB in a Raid 10 conf.
>
> Does the A1000 support this much capacity?

Yes, but the A1000 is almost unusable, that is a really slow device. We will keep it to put archive logs in it.

>> - no special features except a battery buffered cache
>
> You mention elsewhere that its mainly DSS. DSS isn't write
> intensive as far as I'm aware.

Well but at some time, data will be loaded into the DB. In our case, every night in a bunch.

>> This is a quite modest system I think. Be aware that a very fast
>> system could even be inappropriate for this old fashioned machine (4
>> SPARC 2 CPUs at 400 MHz), but of course, latency can never be small
>> enough for scattered I/O operations.
>
> Scattered I/O? With DSS?

Whenever we can avoid full table scan, we do it. That is where scattered I/O comes to play.

>> PS: By the way, nowadays some disks are so fast, that they can almost
>> reach a sustained transfer rate of 70 MB/s in single mode!
>
> Yes, FC-AL is fast.

Ultra160 is SCSI too, isn't it?

Bye
Rick Received on Tue Aug 20 2002 - 16:23:47 CDT