Re: With 4 disks should I go for RAID 5 or RAID 10 - Mailing list pgsql-performance

From Fernando Hevia
Subject Re: With 4 disks should I go for RAID 5 or RAID 10
Date
Msg-id 0f8201c847f6$08e15090$8f01010a@iptel.com.ar
Whole thread Raw
In response to Re: With 4 disks should I go for RAID 5 or RAID 10  (Mark Mielke <mark@mark.mielke.cc>)
Responses Re: With 4 disks should I go for RAID 5 or RAID 10  (david@lang.hm)
List pgsql-performance
Mark Mielke Wrote:

>In my experience, software RAID 5 is horrible. Write performance can
>decrease below the speed of one disk on its own, and read performance will
>not be significantly more than RAID 1+0 as the number of stripes has only
>increased from 2 to 3, and if reading while writing, you will not get 3X as
>RAID 5 write requires at least two disks to be involved. I believe hardware
>RAID 5 is also horrible, but since the hardware hides it from the
>application, a hardware RAID 5 user might not care.

>Software RAID 1+0 works fine on Linux with 4 disks. This is the setup I use
>for my personal server.

I will use software RAID so RAID 1+0 seems to be the obvious choice.
Thanks for the advice!



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