Re: [squid-users] Veritas filesystems and Squid

From: Joe Cooper <joe@dont-contact.us>
Date: Fri, 17 Aug 2001 18:53:59 -0500

Wojciech Puchar wrote:

>>Also, in reading the documentation on the web, I saw somewhere
>>recommended that RAID5 *not* be used as the target disk(s) for
>>the cache. In trying to maintain uptime, should a disk go bad,
>>using RAID5 would give us a WIN situation. What are the reasons
>>to NOT use RAID5, and do you think they outweigh keeping a
>>
>
> RAID5 have sloooow writes.

Wrong. RAID5 actually has quite fast writes (under most workloads, they
are faster than single disk writes--though not for Squid). It's the
reads that are a problem for Squid. Seeks are the primary concern for
Squid workloads, and because RAID5 divides data across multiple disks,
seeks have to be performed up to N times for each object (where N is the
number of disks in the array).

Writes under a Squid workload on a RAID5 array would not be
significantly slower--and probably would be faster on a high end RAID
controller with a nice chunk of NVRAM.

This has all been discussed at length in the past here...and well worth
searching for, for those who don't understand and would like to.
                                   --
                      Joe Cooper <joe@swelltech.com>
                  Affordable Web Caching Proxy Appliances
                         http://www.swelltech.com
Received on Fri Aug 17 2001 - 17:47:45 MDT

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