[OpenAFS-devel] tuning underlying filesystems for afs
Thu, 14 Oct 2004 19:14:51 +0200
On Oct 14, 2004, at 5:50 PM, Martin MOKREJ=8A wrote:
> I'm installing new afs cell and configuring huge afs server - 1TB
> raid5 array on a dual-controller based on adapter U160. It has 6 GB=20
> 2 xeon CPU's 3 GHz. It runs linux-2.4.28-pre3 kernel.
> AFS has inode based and namei based fileservers. What is their=20
> in terms of performance?
There isn't any reason for installing an inode fileserver and Linux=20
fileservers are namei by default.
=46rom now on I'm referring to namei fileservers...
> Filesystems are usually tuned for large or small files. What is the=20=
> case of
> fileserver? The /vicepX partitons are mostly filled with few small=20
> which corresponde to volumes if I'm right. That has nothing to do with=20=
> size of
> files stored in afs volumes, I know ... but should I tune for "huge"=20=
> or "small"
It has to do with the size of your files. What hasn't is your=20
directories but the files will definitely be there but not in any=20
directory you would recognize from where it is on your AFS client.
So if you have a lot of small files ... on your fileserver will be a=20
lot of small files.
Your volumes and files get organized by the fileserver using an=20
algorithm documented based on some hashing but I think you don't want=20
to know about it ;-)
> I expect to have several files above 1GB in afs volumes, in general=20=
> huge files then small ones.
> AFS/kernel mounts /vicepX partitions automatically? However, for=20
> example xfs offers
> several mount options, which affect performance. How can I make=20
> advantage of
> such options under afs?
AFS doesn't do anything by itself!!
Nobody will mount your partitions until you do that (on the server=20
side) and the parameters are in your hands as well. Tune as you want or=20=
The fileserver on startup will just look at directories named /vicepXX.=20=
> I'm attaching my current results from bonnie++ tests. In general, xfs=20=
> is fast
> equally as reiserfs, except random operations. For random operations,=20=
> is the best, them comes ext2, ext3 and xfs as the last one. At least =
> I interpret the numbers correctly.
I can't and won't interpret your decisions regarding the tuning.