Using NFS it sets up what would *seem* to be some pipes in /var/lib/nfs/rpc_pipefs, however some of these seem to have rather odd characteristics and they confuse rdiff-backup so it reports errors due to files apparently changing while it runs.
The specific files in question are these:-
chris$ ls -l /var/lib/nfs/rpc_pipefs/nfs/clnt* /var/lib/nfs/rpc_pipefs/nfs/clnt6: total 0 -r-------- 1 root root 0 2009-08-25 21:42 info
/var/lib/nfs/rpc_pipefs/nfs/clnt7: total 0 -r-------- 1 root root 0 2009-08-25 21:42 info
/var/lib/nfs/rpc_pipefs/nfs/clnt8: total 0 -r-------- 1 root root 0 2009-08-25 21:42 info
Now note that these are reported as normal (but empty) files by 'ls'. Similarly 'file' reports them the same:-
chris$ file /var/lib/nfs/rpc_pipefs/nfs/clnt?/* /var/lib/nfs/rpc_pipefs/nfs/clnt6/info: empty /var/lib/nfs/rpc_pipefs/nfs/clnt7/info: empty /var/lib/nfs/rpc_pipefs/nfs/clnt8/info: empty
But they're not really empty, presumably because they're pipes or fifos or something:-
root@chris:/var/lib/nfs/rpc_pipefs/nfs# cat /var/lib/nfs/rpc_pipefs/nfs/clnt6/info RPC server: garage.local service: nfs (100003) version 3 address: 192.168.1.88 protocol: tcp port: 0 root@chris:/var/lib/nfs/rpc_pipefs/nfs#
This is presumably what's confusing rdiff-backup because they *seem* to be empty ordinary files but they aren't.
Is this normal for pipes/fifos or is there something special about these?