Re: H/W RAID 5 on slower disks versus no raid on faster HDDs

OK now i am reading Momjian's "PostgreSQL Hardware Performance Tuning" 
once again ;-)

mallah.


On Thursday 21 November 2002 23:02, scott.marlowe wrote:
> On Thu, 21 Nov 2002, Rajesh Kumar Mallah. wrote:
> > Hi folks,
> >
> > I have two options:
> > 3*18 GB 10,000 RPM Ultra160 Dual Channel SCSI  controller + H/W Raid 5
> > and
> > 2*36 GB 15,000 RPM Ultra320 Dual Channel SCSI and no RAID
> >
> > Does anyone opinions *performance wise*  the pros and cons of above
> > two options.
> >
> > please take in consideration in latter case its higher RPM and better
> > SCSI interface.
>
> Does the OS you're running on support software RAID?  If so the dual 36
> gigs in a RAID0 software would be fastest, and in a RAID1 would still be
> pretty fast plus they would be redundant.
>
> Depending on your queries, there may not be a lot of difference between
> running the 3*18 hw RAID or the 2*36 setup, especially if most of your
> data can fit into memory on the server.
>
> Generally, the 2*36 should be faster for writing, and the 3*18 should be
> about even for reads, maybe a little faster.

-- 
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)

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