tweaking FreeBSD for Squid using

[Alain Fauconnet]

On Tue, Apr 15, 2003 at 07:31:24PM -0700, Jason Stone wrote:
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> 
> > You didn't mention whether is it SCSI or IDE.
> 
> Based on the fact that it's 15k rpms, I'm guessing scsi - do ide disks
> faster than 7.2k rpms exist?

I don't know. Seems that IDE disks evolve too fast  for  me  nowadays.
That's also why I was writing that I'm  not  even  sure  that  the  old
stance "don't use IDE for servers" is still valid.
OOTH,  I've  had  a lot of trouble  with  busy  IDE-based  (ASUS  P4* m/b)
FreeBSD servers lately (hard hangs, see bug kern/44867).

> 
> 
> > Don't  do  RAID. Bring up a filesystem on each disk (with soft updates
> > of  course),  mount  them  "-o  noatime"  and  configure  Squid to use
> > multiple cache dirs.
> 
> Why is this preferrable to striping with raid-0?

Well, because Squid does load balancing over multiple cache dirs quite
well by itself, and (presumably) in a smarter way than just  spreading
raw disk blocks, so adding another layer of software for RAID-0 doesn't
bring anything, and wastes CPU cycles. I'm not even sure that hardware
RAID-0 is a good idea. According to my own experience (admittedly on a
Linux  box),  removing software striping and using multiple cache dirs
on  physical  volumes  gave  me  a  significant  performance boost and
lowered   the   load   average   of   the   server   by   about   30%.
Since then, I've always stayed away from RAID on Squid boxes, whatever
the O/S.

Er. This is getting off topic  maybe.  I'll  follow  up  privately  if
needed.

_Alain_