HP OpenVMS Systems

Ask the Wizard Questions

Backup compression

The Question is:

    What's the ideal way of backing up directory files, into a compressed
    file format to a 4mm dat tape.  i.e. backup/log [...]*.*;*
    device_name:save_set

The Answer is:

  	BACKUP does not compress files.  It is a matter of fact, BACKUP
    save-sets usually take more space than the sum of all the files in the
    save-set.  That is due to the error detection and correction
    information.  If you want to compress, you need to either compress the
    files first or compress the resulting backup save-set.

    There is software based compression like PKZIP and there is hardware
    compression on some tape drives.