User`s guide
BACKUP
Note:
• You must copy to a saveset even when you are backing up a volume.
A saveset can be thought of as a container that holds one or more files or an
RT–11 volume or device image from a single backup operation.
• You can use wildcards on input files but not on saveset specifications.
• You can type only one output specification for backing up your data.
• Output volumes for backing up data as savesets must be initialized by BUP.
See the /INITIALIZE option for information on initializing backup volumes.
Bad Blocks on the Input Volume
By default, BUP successfully tolerates up to 25 bad blocks on the input device
when backing up a disk to a backup volume or when restoring from a backup
volume to a disk (copy back).
BUP issues a warning message each time it encounters a bad block on the input
device, then continues to back up or restore. If BUP encounters more than 25 bad
blocks on the input device, BUP issues a fatal error message and the operation
is stopped.
You can change the number of bad blocks BUP accepts on the input volume by
using the customization procedure described in the RT–11 System Release Notes.
Description
The BACKUP command has the following primary features:
• Backs up files or RT–11 volumes of any size to any media.
This means you can back up the data from a large volume to as many smaller
volumes as you need.
• Creates more than one saveset on a backup volume, if the volume is large enough.
Since individual files are enclosed in a saveset, you do not have to worry about
multiple copies of the save file (from different backups) overwriting each other.
This means you can back up data from several small volumes to one large volume.
• Creates savesets on magtape that are easily transportable to VAX processors
running the VMS operating system. Once the files on saveset are transported to
a VAX, those files are easily read and manipulated.
• Backs up files to automatically created logical-disk files called subsets.
• Lists directories of savesets, of files in savesets, and of files in logical disks.
• Restores data from savesets and from logical-disk subset files.
RT–11 Command Descriptions 9