RE: [squid-users] Squid performance issue [again]

On Mon, 17 May 2004, Lizzy Dizzy wrote:

> Thanks.
>
> So does it means that the number of partition as well as the total size per
> harddisk does not matter?
>
> As long as the harddisk has multiple spindles, performance would be
> equivalent?

hard-drives have one spindle with one or more platters. all heads move at
the same time. mechanically only one operation occurs at a time. local
read/write caching and really smart schedulers are the only thing that
buys a performance improvement on the disk over having one operation in
flight at a time.

if you have multiple partions for squid on the same disk you're
serializing all of your operations on one drive. you're way better off
with more drives. I'd vastly prefer 2 36GB 15k rpm disks to 1 73GB 10k rpm
disk. our current cache boxes (a little more than a year old) have 4 x
18GB 15k rpm drives each just for cache dirs.

> Regards
> Liz
>
>
> >From: "Elsen Marc" <elsen@imec.be>
> >To: "Lizzy Dizzy" <lizzy_99@hotmail.com>,<squid-users@squid-cache.org>
> >Subject: RE: [squid-users] Squid performance issue [again]
> >Date: Mon, 17 May 2004 10:23:52 +0200
> >
> >
> >
> > >
> > > Hi,
> > >
> > > I understand that the size of the physical RAM has to be
> > > proportional to the
> > > total harddisk cache size. Supposing I have
> > >
> > > unlimited physical RAM,
> > >
> > >
> > > 1) What is the recommended size of 1 physical harddisk for
> > > each server (each
> > > server can have sda, sdb etc...). The reason I
> > >
> > > am asking this is that I am concern that the bigger a disk
> > > is, the longer
> > > squid needs to get an object out of it.
> > >
> > > I am currently using a U320 SCSI disk of 10KRPM, size 73GB.
> > > It is being
> > > partitioned into 4 smaller partition of 17GB each.
> > >
> > > Performace is within expectation, but I am wondering if
> > > reparttioning it
> > > into smaller sizes would give better yield. On the
> > >
> > > other hand, the disk has a fixed number of head, so would it
> > > even help?
> > >
> > > 2) In term of performance only, is a 100GB harddisk better
> > > (partitioned into
> > > 5 20GB partitioned) or 5 20GB harddisks better.
> > >
> > The multiple spindles solution would be better, as SQUID's performance
> > highly depends on (reduced) seek time(s).
> >
> > M.
>
> _________________________________________________________________
> Take a break! Find destinations on MSN Travel. http://www.msn.com.sg/travel/
>

-- 
-------------------------------------------------------------------------- 
Joel Jaeggli  	       Unix Consulting 	       joelja@darkwing.uoregon.edu    
GPG Key Fingerprint:     5C6E 0104 BAF0 40B0 5BD3 C38B F000 35AB B67F 56B2