[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [rdiff-backup-users] rdiff-backup to LinkStation: *slow*
From: |
Felix E. Klee |
Subject: |
Re: [rdiff-backup-users] rdiff-backup to LinkStation: *slow* |
Date: |
Fri, 26 May 2006 12:37:48 +0200 |
User-agent: |
Wanderlust/2.14.0 (Africa) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (Sanjō) APEL/10.6 Emacs/21.4 (i486-slackware-linux-gnu) MULE/5.0 (SAKAKI) |
At Fri, 26 May 2006 09:51:33 +0000 (GMT),
Chris Wilson wrote:
> > According to "top", the "ssh" server "dropbear" seems to be the limiting
> > factor.
>
> You could try making sure that SSH compression is turned off as well. That
> can eat quite a bit of CPU.
By default it should be off, but I tried again:
$ time cat foo | \
ssh -o Compression=no address@hidden "cat >/mnt/hda/share/sshtest.1/foo"
address@hidden's password:
real 19m12.086s
user 1m29.274s
sys 0m21.933s
=> Almost no change in data rate, when compared to the test I did
without "-o Compression=no".
> You can also change the SSH encryption algorithm on the client host
> using the "Ciphers" option in /etc/ssh/ssh_config. According to this
> page, arcfour is faster [http://www.hlrn.de/doc/ssh/index.html]. See
> the man page for ssh_config for details.
The server (dropbear) does not support arcfour. Only aes128-cbc,
blowfish-cbc, twofish-cbc, and 3des-cbc seem to be supported:
$ time cat foo | ssh -o Compression=no -o Ciphers=arcfour \
address@hidden "cat >/mnt/hda/share/sshtest.1/foo"
no matching cipher found: client arcfour server
aes128-cbc,blowfish-cbc,twofish-cbc,3des-cbc
real 0m10.557s
user 0m0.011s
sys 0m0.009s
Of course I could try out those as well. But speed is not the only
issue, security is also an issue.
> I don't think it's possible with rdiff-backup. You could try Box
> Backup, which does encrypt data on the client, and is intended to run
> on low-spec devices like the LinkStation. Currently it does encrypt
> the comms channel as well, but I'm sure the developers would be
> sympathetic to providing an option to disable this (I'm one of them).
Box Backup looks very interesting.
--
Felix E. Klee
Re: [rdiff-backup-users] rdiff-backup to LinkStation: *slow*, Felix E. Klee, 2006/05/31