Disk-Performace issue?

Michael Schuh michael.schuh at gmail.com
Tue May 10 03:46:06 PDT 2005


i have the following Problemdescription.
I work on an AMD 2000+ with 2*160GB-Disks
The Diskperformance tested with bonnie or great filewrites/reads with dd
from /dev/zero or /dev/urandom gaves me an Value from 40-55 MBytes/s.

Now i have 2 Directories with ~500.000-600.000 files with an size of ~5kByte.
by copying the files from one disk to another or an direktory on the same disk
(equal behavior), i can see this behavior:

on an PIII 866 the first ~100.000 - 150.000 files
on an AMDK6II450 the first ~100.000 - 120.000 files
on the AMD2000+ the first ~200.000 - 220.000 files
are copied with an relative good performance.

After this count of files are copied, the system-load get higher,
cppustate ist 0,0% idle and the system uses ~80-90%cpu-load,
rest goin to intr and user....

As base i use RELENG_4.

Can anyone explain me from where this behavior can come?
Come thie eventually from the filesytem, or from my disks, so that
these are to hot? (I think not)

I have tried out following commands to copy:
tar -cf - . | ( cd <destdir>; tar -xf .) #the fastest and my lovely :-)
find ./ -type f |cpio -pm <destdir> # half-performace as tar
rsync -av <sourcedir>/ <destdir>/ # smarter then tar but bad performace

mv or any other are not testet while i surely run in to the "too many
Arguments" Problem....

thank you for your suggestions



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