Shell Programming and Scripting

We would be migrating UNIX file system to Linux file system.
We do have many directory and sub directories with files.

after migrating unix to linux file system , i want to make sure all the files has been copied ? What would be the best approach to validate directory ,sub-directory and file size.

Please advise.

du command ?

It would help if you tell what file systems are used on the source and destination machines, what Unix OS is used, and what method you plan to use to perform the copy.

In any case, "du" is the wrong tool to check the proper copy.

If you really want to make sure all the files are copied without any corruption, create a hash/checksum of every file on the source side and use it to check it is correct on the destination one for each file.

You would also need to make sure all (empty) directories are created and possibly decide what to do with files taht are neither plain files nor directories.

Finally, you might also want to check the permissions, owner/group, extended attributes and ACLs if any.