In response to your post below,

Did you mean VMS? If so, here's how to do it easily:

$ SHOW DEV
.. a list of devices will show up.

$ BACKUP/IMAGE/VERIFY (sourcedisk) (destdisk)

where sourcedisk and destdisk will probably look something like DKA100: or DKB200. This will create a functional equivalent, bootable backup of your system disk. You need to be certain which disk is which. If you're trying to backup your boot disk, use

$ SHOW LOGICAL SYS$DISK:

The LNM$SYSTEM_TABLE entry will be the name of your boot or system disk. Use it in the (sourcedisk) placeholder above.

I hope this helps.

Tiberius