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

[Chris Wilson]

Hi Felix,

On Fri, 26 May 2006, Felix E. Klee wrote:

> > > that would be your problem.
> > > i bet its cpu bound
> >
> > I'll try turning off compression.  Perhaps that helps.
>
> 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.

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.

> There's an alternative that I have in mind:
>
> 1. Encrypt the data on the client machine.
>
> 2. Send it via an unencrypted channel to the LinkStation.
>
> 3. Leave it on the LinkStation in an encrypted state.  This has a huge
>  advantage: I could easily transfer the data from the LinkStation to an
>  Internet backup site, where I definitely don't want it to be stored
>  unencrypted.
>
> Would this be possible with rdiffbackup?  If not, what software solution
> should I look into?  There surely are some, offered by providers of
> remote backups.

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).

Cheers, Chris.
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