Solaris

Hello guys anyone know how to check the size of files in the a backup tape?

Well, it all depends on who wrote what to the backup tape. Then, do you mean individual files or all files as put on tape, and that could be compressed or uncompressed. The tar tv options is nice for seeing files on a tar archive.

Code:

$ tar tjvf- Bugs/4339.tar.bz2
drwxrwxr-x dpickett/dpickett 0 2011-12-09 09:34 Bugs/4339/
-rw-rw-r-- dpickett/dpickett 7569 2011-12-09 09:34 Bugs/4339/slave-recover-logs.txt
-rw-rw-r-- dpickett/dpickett 1054 2011-12-08 15:29 Bugs/4339/launch-job-console-log.txt
-rw-rw-r-- dpickett/dpickett 9395 2011-12-08 15:26 Bugs/4339/server-recover-logs.txt
-rw-rw-r-- dpickett/dpickett 38888 2011-12-07 17:09 Bugs/4339/prom_error_logs.txt
$

There is no simple answer to your question. It is much too vague.
The phrase "check the size of files in the a backup tape" has no meaning in a commercial environment. What do you actuallly want to know?

If the tape was created with unix commands, please mention the unix commands used.

If the tape was created with commercial backup software, please mention the name of the commercial backup package and the version.

An of course don't forget to mention the make and model of the backup tape device and the exact type of tape cartridge.