Date: Tue, 13 Jun 2000 22:44:42 -0600 From: Wes Peters <wes@softweyr.com> To: Jaye Mathisen <mrcpu@internetcds.com> Cc: hackers@FreeBSD.ORG Subject: Re: Has anybody looked at RAID-5 vinum performance on the "whole system"? Message-ID: <39470DBA.D8045A1A@softweyr.com> References: <Pine.BSF.4.21.0006131635260.11271-100000@schizo.cdsnet.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Jaye Mathisen wrote:
>
> I was just curious what people's thoughts were on the potential "total
> system throughput" (whatever you choose it to be), wrt using software
> RAID.
>
> It would seem that software RAID would just kill big chunks of cache,
> especially CPU cache, moving lots of data throught it to calcuate CRC's.
>
> perhaps the raid 1/0's would be fine, since the calcuation could be
> ignored.
Greg can probably give a better answer than I can, but one thing to be
aware of is that host-based RAID, like Vinum, usually has access to a
lot more processor and memory resources than hardware RAID controllers.
My experience is limited to running an I/O bound, not compute-bound,
server using both Vinum and a Mylex DAC1100 with 64MB RAM, using RAID-1.
The system was a DELL 2400 with 2x 600 Mhz Pentium III. The application
was a non-interactive web filter running over millions of web pages
grabbed by a spider. The total throughput was significantly higher on
the software RAID system. The application inherently sloshes through
the caches anyhow, so little cache affect is achieved.
--
"Where am I, and what am I doing in this handbasket?"
Wes Peters Softweyr LLC
wes@softweyr.com http://softweyr.com/
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?39470DBA.D8045A1A>