Tar (but not cp) is incredible slow on certain dirs; request for comments/solution ideas/clues.

Thorsten Ohl (ohl@hep.tu-darmstadt.de)
Thu, 21 Jan 1999 18:39:05 +0100 (CET)


Michael Weller <eowmob@exp-math.uni-essen.de> writes:

> Anyway, effect under all those kernels/# of CPU's is as follows: I
> try to backup / (whole linux is in one partition) to another disk,
> file on same disk, or even /dev/null (it doesn't matter). It runs
> nicely. But when it comes to /usr/src/linux-2.2.0pre7 where the
> 2.2.0pre7 sources are, it slows down to a crawl. That means it
> backs up one of these really tiny *.c and *.h files there per 1 or
> 2 seconds. Basically, it is impossible to back this dir up in any
> reasonable time.

Do the numeric uids/gids under /usr/src/linux-2.2.0pre7 correspond to
a known user? (Try `find -nouser'). If not, tar can become _really_
slow asking NIS for a username for each file anew.

I had this phenomenon when I upgraded my home machine to SuSE 6.0
with libc6. The default /etc/nssswitch.conf has NIS included, even if
NIS is not installed.

-- 
Thorsten Ohl, Physics Department, TU Darmstadt -- ohl@hep.tu-darmstadt.de
http://heplix.ikp.physik.tu-darmstadt.de/~ohl/ [<=== PGP public key here]

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