Re: [squid-users] about ufs and aufs

Thanks for your infromation. I need some further clarification..

I have tested squid with 200 req/sec with enabling the aufs.But in cache log
i am getting the warning "Queue congestion - Disk I/O" .

How can I overcome this problem? how can we calculate the number of
threads needed...?

RH7.1
squid2.4STABLE1
512MB RAM,
3X5GB cache

Thanks.

----- Original Message -----
From: Brian <hiryuu@envisiongames.net>
To: mani <balu_2003@yahoo.com>; <squid-users@squid-cache.org>
Sent: Sunday, August 05, 2001 2:11 AM
Subject: Re: [squid-users] about ufs and aufs

> On Friday 03 August 2001 11:45 pm, mani wrote:
> > Hi,
> >
> > What is the the difference between ufs and aufs. As I know both are file
> > system of the squid.In ufs mode it handles the request as single
> > processes but in case of aufs it handles the request in a
> > multiprocesses.. am I correct here, if not educate me.
>
> Multiple threads. Threads are lightweight processes that share the same
> memory space, making switches between them very fast. Squid also has a
> multi-process storage system, diskd.
>
> > What is advantage and disadvantages of ufs mode? What we achieve when we
> > go aufs..? How these both mode works..?
>
> Disk operations block the process making the request until the data is
> available. In ufs, squid handles the io operations itself, which means it
> blocks on disk IO and will not scale very far. In aufs, squid hand the io
> operations off to other threads. Those threads block, but the main squid
> continues normally.
>
> The problem with aufs is threads are not well supported (either by squid
> or even the OS itself) on all systems. It also incurs some CPU overhead
> from squid 'tending the flock' of threads.
>
> Redhat 7 should handle threads just fine, so use aufs if this squid will
> be seeing a decent amount of traffic.
>
> -- Brian

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Received on Sun Aug 05 2001 - 23:47:20 MDT