rsync with --copy-devices patch and device-target with --write-batch doesnt work

[Matt McCutchen]

On Sat, 2009-01-24 at 11:32 +0100, Freisei wrote:
> I want to use rsync to create differential backups of my lvm-snapshots.
> 
> fullbackup-filename: /mnt/sdc1/snapshotvergleich/rootbackup1.img
> current snapshot: /dev/vg0/rootbackup
> 
> note: compiled-in --copy-devices-patch
> 
> 
> root at xp8main3:/usr/local/src/rsync# ./rsync --version
> rsync  version 3.1.0dev  protocol version 31.PR5
> Copyright (C) 1996-2009 by Andrew Tridgell, Wayne Davison, and others.
> Web site: http://rsync.samba.org/
> Capabilities:
>     64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints,
>     socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace,
>     append, no ACLs, xattrs, iconv, symtimes
> 
> rsync comes with ABSOLUTELY NO WARRANTY.  This is free software, and you
> are welcome to redistribute it under certain conditions.  See the GNU
> General Public Licence for details.
> root at xp8main3:/usr/local/src/rsync# ./rsync -v --progress  
> --write-batch=/mnt/testvol/diff1_2_usb_copydiff 
> /mnt/sdc1/snapshotvergleich/rootbackup1.img /dev/vg0/rootbackup
> rootbackup1.img
>      53,116,928   0%   50.62MB/s    0:03:26
> rsync error: error in file IO (code 11) at io.c(1565) [sender=3.1.0dev]
> root at xp8main3:/usr/local/src/rsync#

That line number corresponds to a failure to write data to the batch
file.  Rsync ought to print an informative error message when this
happens; I'll submit a patch for that when I get a chance.  In the
meantime, you can strace rsync to see how the write(2) call is failing.

-- 
Matt