info-vax@ucbvax.ARPA (07/04/85)
From: Peter Stokes <stokes%cmc.cdn%ubc.csnet@csnet-relay.arpa>
I have gathered several questions in the past while that will
hopefully create some discussion....
1) Does anybody really know the difference between using BACKUP and
BACKUP/IMAGE when performing a stand alone backup of a system.
During a DEC course I recently attended we were informed that
/IMAGE must be used otherwise a restore on a brand new disk
would not work. The DEC manual (Utilites Reference Manual)
does not indicate whether using /IMAGE is essential for a reliable
stand alone backup. To add to the confusion... DEC software
support in Colorado Springs were positive that the /IMAGE qualifier
is implied in stand alone backup and therefore redundant to include
in the command line.
2) Does anybody know of a quick way of actually erasing a mag tape?
The INITITALIZE command is reversable and sometimes we need to
send out a blank tape without the possiblity of its previous
contents being read.
3) Does anybody know of a method of changing the modified date of
many files across a disk? I once forgot the /RECORD qualifier
on a backup and ended up having to do it all over again to get
the date right.
last question I promise...
4) Using the accounting utility, is there a way of finding the total
CPU that was available between the time extremes? I could calculate
it by hand using the dates and times supplied or I could write a
program to extract the info from a binary version of accountng.dat
BUT it would be nice....
We have a 780 running VMS V3.7.
Thanks in advance for any help...
Peter Stokes
Canadian Microelectronics Corporation
Queen's University, Kingston Ontarioinfo-vax@ucbvax.ARPA (07/04/85)
From: Tony Li <Tli@Usc-Eclb>
From: Peter Stokes <stokes%cmc.cdn%ubc.csnet at csnet-relay.arpa>
1) Does anybody really know the difference between using BACKUP and
BACKUP/IMAGE when performing a stand alone backup of a system.
During a DEC course I recently attended we were informed that
/IMAGE must be used otherwise a restore on a brand new disk
would not work. The DEC manual (Utilites Reference Manual)
does not indicate whether using /IMAGE is essential for a reliable
stand alone backup. To add to the confusion... DEC software
support in Colorado Springs were positive that the /IMAGE qualifier
is implied in stand alone backup and therefore redundant to include
in the command line.
BACKUP/IMAGE need only be used when initializing a new disk under
normal backup. TSC is correct in saying that /IMAGE is implied under
stand alone backup. I think the confusion lies in your DEC course.
The instructor must have been talking about normal BACKUP and not made
himself clear.
2) Does anybody know of a quick way of actually erasing a mag tape?
The INITITALIZE command is reversable and sometimes we need to
send out a blank tape without the possiblity of its previous
contents being read.
There are bulk-demagnetizers which are available from your local
electronics store for reasonable amounts of money. The only other way
is to completely write over the tape, or to use a new tape.
Cheers,
Tony ;-)info-vax@ucbvax.ARPA (07/05/85)
From: sasaki@harvard.ARPA (Marty Sasaki) One solution to forgetting to use the /record switch is to do the backup again with the /record but to direct the output to NLA0:. It still takes a little while to do the backup, but it isn't as bad as doing the backup all over again to tape or disk. Marty Sasaki