incremental backups via ftp

[Christian <news@nerdbynature.de>]

Hi,

we're having this box with 30GB of /webspace to backup (plus /etc and a few 
things from /usr/local) but our hosting provider is only offering a FTP server 
to backup. This might not be unusual and given the fact the we have 80GB of 
backupspace, this is pretty neat. However, I fail to get a proper backup 
solution working. I see a few options:

  * upload /webspace directly to the ftp server with e.g. sitecopy(1)
	- tried that, not working: sitecopy may fail after a few
          gigabytes, leaving the statefile empty/scrambled/unusable.
        - fine grained --exclude options are tricky to apply :(

  * I've written a shellscript (sh) generating .tar files on-the-fly
    while uploading to the backup server (tar | ncftpput).
	- good, because no local backupspace is need (which might
          not be available anyway)
	- I failed to get incremental backup working, so the daily
          backup process took longer and longer as the /webspace grew
          (~6h!), also the ftp server occasionally closed the connection
	  because the backups took so long.

  * Eventually I stumbled upon reoback[0], which is basically making
    a full backup the local disk, then uploading to the ftp server and
    deleting the local copy, then making local incremental backups,
    uploading them to the ftp, until another full backup is due.
	- while I had to make room for the initial full-backup, the
          following incremental backups seemed promising.
        - however, reoback is also taking hours to do the job, I tried
          to just create .tar, not .tar.gz - to no avail. As the backups
          take too long, the ftp server may close the connection again
          and another ~5h of heavy load due to the backup process are
          going down the drain :(

So, my question is: how do you do this? How do you backup your systems? How do 
you backup 100 GB? 500 GB? Daily? Weekly? Are rsync-enabled
backupservers really this seldom? (And if so, what might be the reason?
security? user management?)

Thanks for any hints,
Christian.

[0] http://reoback.sf.net/
--
BOFH excuse #230:

Lusers learning curve appears to be fractal