Re: some testing questions

[Ingo Bormuth <ibormuth@efil.de>]

On 2006-08-14 16:15, Vladimir V. Saveliev wrote:
> reiser4progs incluses a program measurefs.reiser4. It should be able to 
> measure tree fragmentation. I am not sure how does portage tree evolve, but 
> maybe it could be interesting too see how does reiser4 tree fragmentation 
> change when filesystem is loaded regularly.

This is a reiser4 partition holding the following:

  - portage tree (synced every three days)
  - ccache (compiler cache allowed to grow to 3GB - recently cleared)
  - firefox's and opera's cache
  - /tmp (portage builds everything in here)

The filesystem was created around 1.5 years ago (how can I say).

#cat /proc/version
Linux version 2.6.17.8-reiser4-r3 (root@kruemel) (gcc version 3.4.6 (Gentoo 3.4.6-r1, ssp-3.4.5-1.0, pie-8.7.9)) #2 Sat Aug 12 12:03:25 CEST 2006

#df:
/dev/hda8              6357768   3478716   2879052  55% /cache

#cat /etc/fstab:
/dev/hda8  /cache  reiser4  noatime,nodiratime,nodev,nosuid,tmgr.atom_max_age=500000  0 0

#measurefs.reiser4 -S:
measurefs.reiser4 1.0.5
Copyright (C) 2001, 2002, 2003, 2004 by Hans Reiser, licensing governed by
reiser4progs/COPYING.

Tree statistics ... done
Packing statistics:
  Formatted nodes:    3622.85b (88.45%)
  Branch nodes:       2792.00b (68.16%)
  Twig nodes:         3233.75b (78.95%)
  Leaf nodes:         3966.47b (96.84%)

Node statistics:
  Total nodes:         871653
  Formatted nodes:      75571
  Unformatted nodes:   796082
  Branch nodes:            23
  Twig nodes:            1360
  Leaf nodes:          870270

Item statistics:
  Total items:         542211
  Nodeptr items:        75570
  Statdata items:     214695
  Direntry items:       37432
  Tail items:          207819
  Extent items:          6695


Tree fragmentation: 0.074648

Data fragmentation: 0.039962

Last week I recompiled gcc and afterwards cleared 3GB of ccache data. 
Before doing so, the partition was >90% full. My feeling is that now 
that it's half empty performance is much better. Emerge sync used to 
take _ages_ rebuilding its cache and now is quite fast. Also CPU usage 
during compilation seems much lower. I can't remember to ever hear the 
CPU fan running during recent compilations (700MHZ PIII). Before clearing 
the cache it ran continuously and still felt hot.

I know none of this is hard data. If you are interested in a follow up,
just let me know.


BTW: Is it save to run measurefs.reiser4 -S -T -D on a mounted fs ?

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