Re: Bad RAID1 read performance - Mailing list pgsql-performance

From Albert Cervera Areny
Subject Re: Bad RAID1 read performance
Date
Msg-id 200705311300.50306.albert@sedifa.com
Whole thread Raw
In response to Re: Bad RAID1 read performance  ("Luke Lonergan" <llonergan@greenplum.com>)
List pgsql-performance
As you suggested with two threads I get 42.39 Mb/s in one and 40.70 Mb/s in
the other one, so that's more than 80Mb/s. That's what I expected with a
single thread, so thanks for the information. It seems I will have to buy
better hard drives if I want increased performance...

A Dimecres 30 Maig 2007 22:13, Luke Lonergan va escriure:
> Not for one thread/process of I/O.  Mirror sets can nearly double the read
> performance on most RAID adapters or SW RAID when using two or more
> thread/processes, but a single thread will get one drive worth of
> performance.
>
> You should try running two simultaneous processes during reading and see
> what you get.



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