“rsync: failed to set permissions on …” error with rsync -a or -p option

Question

When I use the -a option as is asked and answered in Preserve the permissions with rsync, I got a lot of "rsync: failed to set permissions on" errors.

rsync: failed to set permissions on "/ata/text/RCS/jvlc,v": Operation not permitted (1)
rsync: failed to set permissions on "/ata/text/RCS/jvm,v": Operation not permitted (1)
rsync: failed to set permissions on ...

Why is this? The files are normal files with permission of 0664.

Answer 1

Most likely, rsync on the destination end is not running as a user with permission to chmod those files (which would have to be either the file's owner or root).