BackupPC

References

rsync

• How Rsync works
• A patch for rsync about computing and caching checksums

Troubleshooting

Broken pipe

Typical errors:

rsync_bpc: writefd_unbuffered failed to write 426 bytes to message fd [receiver]: Broken pipe (32)

Possible causes and solutions

• Happens more frequently with big files, but some small files fail too. Not always the same file
• Timeout issue
• Firewall
• Lots of packet loss / reject. The following iptable route might help [1]:

iptables -I {line} -p tcp --tcp-flags SYN,RST,ACK,FIN ACK -j ACCEPT

Links

• Interesting discussion on samba.org, with troubleshooting ideas.

 strace -tt -f -o /tmp/rsync-$$.out rsync \
       --verbose \
       --exclude "stor/hosts" \
       --exclude "var/run" \
       --exclude "var/spool" \
       --rsh="ssh -p $backoff_port" \
       --rsync-path="sudo /usr/local/bin/rsync-debug" \
       --recursive \
       --links \
       --perms \
       --times \
       --owner \
       --group \
       --numeric-ids \
       --xattrs \
       --delete \
       --compress \
       --human-readable \
       --stats \
       --exclude='udat/backup*/*' \
       --exclude='udat/migrate/*' \
       /mnt/stor \
       $userid@$backoff_url:$destdir 2>&1