[rdiff-backup-users] rdiff-backup to LinkStation: *slow*

[Felix E. Klee]

I've successfully installed rdiff-backup on a Buffalo LinkStation.
However, to my disappointment, it's dog slow when compared to plain ssh,
especially when many small files are to be backed up:

  /tmp$ du -sh ls
  398M    ls
  /tmp$ find ls | wc -l
  12772
  /tmp$ time rdiff-backup ls/ address@hidden::/mnt/hda/share/test
  address@hidden's password: 

  real    148m4.930s
  user    0m13.059s
  sys     0m3.196s

  /tmp$ du -sh ls2
  4.0G    ls2
  /tmp$ find ls2 | wc -l
  2
  /tmp$ time rdiff-backup ls2 address@hidden::/mnt/hda/share/test2
  address@hidden's password: 

  real    113m52.755s
  user    0m50.338s
  sys     0m28.332s
  
There was other traffic on the LAN while the backup was performed, but
that should be negligible.

Any ideas whether speed can be improved and, if so, how?

If rdiff-backup really is too resource hungry, what other tools do you
recommend for doing incremental backups (I need history) over 100MBit
LAN?  Personally, I've experience with star (a TAR implementation) and
rsnapshot (based on rsync), but rdiff-backup seems to be the most
comfortable solution for me.

Details:

* Software on the LinkStation: librsync 0.9.7, rdiff-backup 1.0.4,
  dropbear 0.46 (SSH).

* Software on the client: librsync 0.9.7, rdiff-backup 1.0.4, OpenSSH
  4.3p1, OpenSSL 0.9.7g.

* Hardware of the Linkstation: Mipsel CPU at 400MHz, ca. 64MiB RAM,
  160GB HD at 7200RPM, 100MBit/s LAN.

* Hardware of the client: Thinkpad T41 with 1.6GHz Pentium-M, 1GiB RAM,
  100GB HD at 5400RPM, 10/100/1000MBit/s LAN.

-- 
Felix E. Klee