Use tar to online backup has an error

Hi,

when I use tar to online backup ,It has an error:

/bin/tar: Removing leading `/' from member names

/bin/tar: /data/test/PG_9.0_201008051/20001/24500001: Cannot stat: No such
file or directory

/bin/tar: Error exit delayed from previous errors

and /data/test/PG_9.0_201008051/20001/24500001 file is not exist.

[~]$ ls -al /data/test/PG_9.0_201008051/20001/24500001

ls: /data/test/PG_9.0_201008051/20001/24500001 : No such file or directory

what should I do to resolve this error.

I'm using pg9.0.

Thanks