RE: [squid-users] Hardware Recommendations

Thank you,

So if I may provide a scenario, I have one last question:
I will Mirror 2 36GB 15K SCSI drives for the OS and logs..Will rotate the
logs etc...
I will install two additional disks, each 72GB 15K SCSI Ultra3 drives, no
raid, just individual drives and place a cache_dir on each.
~40GB each of cache...
If one of the cache drives fails, what happens to squid when it can't find
it?

Thanks..

-----Original Message-----
From: john allspaw [mailto:jallspaw@yahoo.com]
Sent: Thursday, October 13, 2005 1:56 PM
To: Matus UHLAR - fantomas
Cc: squid-users@squid-cache.org
Subject: Re: [squid-users] Hardware Recommendations

at the risk of repeating what has been posted here before, here are some
considerations.
 these are based on my experience with squid and hardware, almost all on
reverse-proxy/acceleration setups:

 - get fast disk. ignore information that says SATA is just as good as
SCSI. nothing beats 15K RPM SCSI drives, and get ones with lowest seek
times
 - don't use RAID. just don't. it's a cache, and if you lose a disk, I
might argue that even if it's mirrored, the degradation during a rebuild
might be too much. just let the disk go, kiss its contents good bye, and
install a replacement
 - get a lot of disk, and put one cache_dir on it. don't use up the whole
disk, read the FAQ on memory usage, and make sure you're not giving too much
to disk. it'll be fast at first, but if it's too big, then you'll be sorry
later when it's full. :)
 - put your logs on a different physical spindle as a cache_dir. or better
yet, don't log all the time. :)
 - mount ext2, noatime

 those things I've found to be the fastest.

 oh also: contrary to popular belief, I don't have numbers on it, but I
don't think that there is a huge diminishing return with adding over 3
spindles.
 I have 6 spindles, and they are a huge improvement over just 2 or 3
spindles.

 --john

----- Original Message ----
From: Matus UHLAR - fantomas <uhlar@fantomas.sk>
To: squid-users@squid-cache.org
Sent: Thu Oct 13 01:02:08 2005
Subject: Re: [squid-users] Hardware Recommendations

On 12.10 20:30, Timothy Bushart wrote:

Please, set up quoting in your mail client...

> On 12.10 14:13, TBUSHART@nycap.rr.com wrote:
> > Can anyone help and make any recommendations from their experiences for
> > hardware requirements for a new install of two LVS Load balancers
> > forwarding to two Squid Real Servers. I?ve got the LVS servers in
> > place, but for the squid boxes,
>
> > should I use multiple hard drives with
> > Raid 5 or Mirror two 15K SCSI drives,
>
> no! if RAID, only RAID1 (mirror), if you can afford it, read more on:
> http://www.squid-cache.org/Doc/FAQ/FAQ-3.html#ss3.11

> Raid 1, 2 146GB 15k SCSI Mirrored Drives for OS and Logs, and two
partitions
> for cachedir's..

only one cache_dir on one drive (or mirror). Using more cache_dir's on the
same disk is just inefficient.

> could I get away with:
>
> cache_dir diskd /cache1 32000 16 256
> cache_dir diskd /cache2 32000 16 256
> (Each partition will be 64GB, only use 32GB for cache on each partition)

that should be OK, you can even use bigger cache (48GB)

> Recommendations call for one cache_dir per disk, but if you have two disks
> mirrored RAID1, does that mean use a single cache_dir.... or will two
> cache_dirs suffice?... because the larger the cache_dir the more memory
> used...

RAID1 here behaves as one disk and that means you should use single
cache_dir
on it.

> Currently in production we have two squid servers - pentium III's 1.5GHZ's
> raid 5 (3 76GB Drives) with 4 cache_dirs...Only about a 1-2 second delay

if you set up no raid or raid1 here (and use one cache_dir per raid), you'd
probably notice berformance advantage, even with hardware raid, and
especially with software raid. maybe you won't need new machines at all :-)

> before a web page is brought up This is with cache_peer parents that are
new
> McAfee webshield web scanners, and 2 new DNS servers that receive about 20
> queries/sec. This was inherited from someone that left the company. We
have
> to upgrade and want to make sure performance increases with new hardware
and
> doesn't decrease. I read somewhere some guy upgraded his squid system with
> new hardware and his users started complaining that the web slowed down, I
> trying not to be that guy, and I'm reading alot...www.squid-cache.org

--
Matus UHLAR - fantomas, uhlar@fantomas.sk ; http://www.fantomas.sk/
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