[mod.computers.vax] Backup continuation tapes.

MACALLSTR%vax1.physics.oxford.ac.uk@CS.UCL.AC.UK (09/04/86)

We've been using BACKUP and writing to several continuation tapes. We have
 restored data on several occasions, including full disk restores, without
 trouble.

In our regular backup procedures I specify /DENSITY in both the MOUNT and
 BACKUP commands. I also use the /LABEL qualifier in the BACKUP command
 and allow BACKUP to write its own continuation labels : our local software
 keeps track of which 'sticky label' relates to which backup tape. 

Some general advice for anyone writing tapes on any system. When writing tapes
 specify the DENSITY wherever a command allows. My past experience has shown
 this is the only way to GUARANTEE that your tape is being written at the
 particular density. Software/hardware bugs/defaults can make the outcome
 uncertain. Reading tapes, provided the drive supports the particular density,
 is usually more reliable.