I have the same issue.
update from 6.0.10 -> 7.0.0 -> 7.0.1
I see my backup place growing, growing too much.
I list my /opt/zimbra/backup/sessions/ and I see too much sub-folders names *full* or *incr*
Surprise, zmchedulebackup display only full ou incr but no deletion.
Not enough time to see if crontab -e give me zmbackup -del, i launch zmschedulebackup -D to restore default et relaunch my usual configuration (i prefer 10 days for deletion because of space ).
Now I still can see my crontab -e like that (i don't modify anything, zmchedulebackup did)
but my zmchedulebackup still not display my deletion
# BACKUP BEGIN
0 1 * * 6 /opt/zimbra/bin/zmbackup -f -a all
0 1 * * 0-5 /opt/zimbra/bin/zmbackup -i
0 0 * * * /opt/zimbra/bin/zmbackup -del 10d
# BACKUP END
my tests have been made on ubuntu 8.04 32bits and 64 bits.
f 0 1 * * 6 -a all
i 0 1 * * 0-5
Pay attention when update, you have to modify your backup
(and receive errors when launch the /opt/zimbra/libexec/scripts/migrate20100913-Mysql51.pl)