Re: Advice on RAID card - Mailing list pgsql-performance

From Greg Stark
Subject Re: Advice on RAID card
Date
Msg-id 873bntjb9p.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: Advice on RAID card  (PFC <lists@boutiquenumerique.com>)
Responses Re: Advice on RAID card  (Michael Stone <mstone+postgres@mathom.us>)
List pgsql-performance
PFC <lists@boutiquenumerique.com> writes:

>     Which makes me think that I will use Software Raid 5 and convert the
> price of the card into RAM.
>     This should be nice for a budget server.
>     Gonna investigate now if Linux software RAID5 is rugged enough. Can
> always buy the a card later if not.

Raid 5 is perhaps the exception here. For Raid 5 a substantial amount of CPU
power is needed.

Also, Raid 5 is particularly inappropriate for write-heavy Database traffic.
Raid 5 actually hurts write latency dramatically and Databases are very
sensitive to latency.

On the other hand if your database is primarily read-only then Raid 5 may not
be a problem and may be faster than raid 1+0.

--
greg

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