To get good random access (and sustained read/write) performance
be sure to have command queuing (either TCQ or NCQ)
- available,
- configured and
- working
on all components used: Disk, controller and driver.
The latest is particulary an issue with XP.
Still, similar 15 kRPM SCSI raid will easily outperform SATA,
So the true question is whether you need the high (SCS, FC, ..) performance at
high costs or not.
We here estimated which sustained write rate we need,
found a supplier who promised us (a much better) througput,
so we made a contract with acceptancy check based, among other things,
on the sustained write rate as well.
The real write rate was much smaller than promised but still much higher than
required,
so we got an rebate and kept the 3 TB raid - and are happy with it.
Best
Juraj
-----Ursprüngliche Nachricht-----
Von: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] Im Auftrag
von Richard Rhodes
Gesendet: Mittwoch, 11. Juli 2007 20:40
An: ADSM-L AT VM.MARIST DOT EDU
Betreff: Re: SATA disk?
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 07/11/2007
02:01:16 PM:
> Has anyone used SATA drives for primary storage. Is it really a bad
idea?
I've been using some SATA disks for a primary staging pool for a few months.
It was the only storage we had at the time . . . so I used it. This was SATA
in a EMC Clariion. Config'ed as raid5
In general, I was quite happy with it's performance.
Now . . .the BUT's . . .
I grabed about 1tb across 30-40 lightly used spindles in multiple Raid5
raidsets. In other words, I had enough spindles to get the iops/throughput I
needed.
According to EMC's docs, these SATA disks are capable of around 60 iops.
Rick
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