Rsync is a cool utility, especially when I'm trying to plonk my 10Gb backup onto Dreamhost's flaky backup server. But I wish I could make it retry when things go south. There are various threads on doing this, but it would seem it's not built into rsync itself.
The obvious solution is to check the return value, and if rsync returns anything but success, run it again. Here was my first try:
while [ $? -ne 0 ]; do rsync -avz --progress --partial -e "ssh -i /home/youngian/my_ssh_key" /mnt/storage/duplicity_backups firstname.lastname@example.org:.; done
The problem with this is that if you want to halt the program, Ctrl-C only stops the current rsync process, and the loop helpfully starts another one immediately. Even worse, my connection kept breaking so hard that rsync would quit with the same "unkown" error code on connection problems as it did on a SIGINT, so I couldn't have my loop differentiate and break when needed. Here is my final script:
On a side note, duplicity is pretty neat. I only wish it would support resuming of interrupted backup sessions so that I didn't have to do this in two steps. My current backup workflow is
PASSPHRASE="backup" duplicity --encrypt-key 77XABAX7 /home/youngian --exclude "**/.VirtualBox" --exclude "**/.kde" --exclude /home/youngian/tmp/ --exclude /home/youngian/backup/ file:///mnt/storage/duplicity_backups/ --volsize 100
...and then the above rsync script.