ORA-17505: ksfdrsz:1 failed to resize file to size
                                                 Last update (2011-02-22 13:09:10)
                                                                                                                   Date added (2008-05-13 15:08:08)

Summary
If you have setup Rman backup and you get the error ORA-17505: ksfdrsz:1 failed to resize file to size x blocks then the workaround is:

1. Go to $ORACLE_HOME/dbs in the unix filesystem
make $ll -lt sna*
to find the old snapcf_SID.f

2. Rename it to old
$mv snapcf_SID.f snapcf_SID.f.old

3. Do a resync of the catalog

$rman target sys/**** catalog rman/****@rman
resync catalog;

Resyncing will create new snapcf_SID.f

4. Run Rman backup again.