rsnapshot: "No space left on device"

[Detlef Lechner]

Hi,

'~$ sudo rsnapshot hourly' reports:
"rsync: writefd_unbuffered filed to write 4 bytes [sender]: Broken pipe
(32);
rsync: write failed on
"/media/BckupMD9/hourly.0/localhost/home/detlef/tmp/evolution-
backup.tar.gz"; No space left on device (28);
rsync: error: error in file IO (code 11)at receiver.c(302)
[receiver=3.0.5];
rsync: connection unexpectedly closed [32205 bytes received so far
[sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(600)
[sender=3.0.5]"
This is the first time that I get an rsnapshot error message "No space 
left on device".
The backup partition /media/BckupMD9 has left only 601 MiB "unused", but
the file evolution-backup.tar.gz comprises 770 MB.
Thus far I thought that rsnapshot erases automatically the oldest snapshot
(Backup) on the current partition if storage is insufficient for the 
current rsnapshot process. Is this not always true?
My partition /media/BckupMD9 comprises 19,53 GiB. There are 3 rsnapshots 
on it.
How to proceed?

Regards,
Detlef Lechner