Re: [squid-users] file system type/params optimal for squid?

On Sat, 25 Oct 2003, Linda W. wrote:

> Was about to move my squid directory off onto it's own partition and was
> wondering what filesystem to use, in the sense of is there a linux (x86)
> filesystem that performs best for squid? Any special params for block
> size? It's just a single SCSI disk.

The general consensus is that reiserfs mounted with noatime is currently
the best performer for a Linux Squid cache. This conclusion arrived after
countless benchmarks in different configurations, mostly thanks to Joe
Cooper.

But you can always set up your own benchmarks to see what runs best on
your hardware. For benchmarking I highly recommends the polygraph
benchmark program with polymix-4 workload.

Only problem with benchmarking is that you need at least two extra
computers to run the benchmark (one acting as client, one acting as
server), and that it takes some tries before one is used to how to run the
benchmarks..

> I'm guessing but a journaling fs might slow it down?

Depends.

A journalled filesystem can be a lot faster than a syncronous
non-journaled filesystem and also gives a better level of fault tolerance.

A simple asyncronous non-journalled filesystem is almost faster than a
journalled filesystem, but is at the same time very sensitive to errors.

> I recently ran a Sandra filesystem benchmark on FAT32/NTFS and found
> NTFS was around 3-4x slower than FAT32. Suprised me since NTFS is
> supposed to be MS's state-of-the-fart file system, but I wondered if the
> journaling was slowing it.

NTFS is a cool filesystem design, but yes, jornaling slows it down a
little. It is not really fair to compare NTFS to FAT32 on NT as the FAT32
is completely asyncronous with absolutely no fault tolerance.

> I wonder...if one stuck a mySQL database on the back end of squid for a
> FS driver and ran mySQL using one big 'file' that was namd
> /dev/sdAx...or weirder /dev/raw/sdAx (or whatever the syntax would be).

Juck.. why would one want to do so?

> Is it possible it would slow things down if you gave squid too large a
> partition, i.e. is it
> better to have 5% usage of a 10G partition or 50% usage of a 1G
> partition?

On most UNIX type filesystems you should aim for having at least 20% free
space for optimal performance.

> Maybe it's all so dwarfed by network latency, the local fs doesn't
> matter (really just 1-2 users of cache)....-- in fact that's probably
> the case...might as well use a rewritable CD-ROM for all the speed we
> have here (about 1/100th internal 100Bt ethernet)...

Right.. for this setup mostly anything will do I think. But the
rewriteable CD is probably a little too slow (very long setup times for
writing, and cannot read without first terminating the write) and may
eventually wear out both the media and mechanics of the drive..

Regards
Henrik
Received on Sat Oct 25 2003 - 16:51:08 MDT