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HP OpenVMS Systemsask the wizard |
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The Question is: I have 2 questions: 1) I know the difference between the BACKUP and COPY Commands. The backup puts the files in a saveset and the copy command, well essentially copies files. Someone told me that if a file is backed-up vs copied, that the resulting file characteristics are d ifferent if that file is restored or copied back. Is there any truth to that?. 2) I issued the following commands to backup files to a cartridge: $ INITIALIZE MKC500: ALPHA1 $ BACKUP/LOG/BLOCK=16384/IGNORE=(LABEL_PROCESSING) - DRA5:[FRDATA]*.*;* MKC500:FRSDATA.BCK/REWIND Although the files were backed up I did get the following message: %MOUNT-I-MOUNTED, ALPHA1 mounted on _PAULA$MKC500: %BACKUP-I-LBLOVRWRITE, volume label ALPHA1 overwritten, new label is FRSDAT I'm unclear as to why I received this message, since I did use the /IGNORE=LABEL_PROCESSING Parameter. Thank you. The Answer is :
As the OpenVMS Wizard is not familiar with what this Someone
specifically said, it is accordingly difficult to answer your
question and resolve this apparent confusion. There are any
number of different references and different misunderstandings
certainly possible here.
BACKUP provides not only the saveset operations you mention, but
it can also copy directories, and directory trees of files.
Both COPY and BACKUP are intended to provide identical attributes
and identical file contents, but it is possible (with use of
BACKUP/INTERCHANGE, for instance) that certain site-specific
attributes will be stripped off the file.
It is also possible that COPY and COPY/FTP operations through
heterogenous networks can result in file attributes being stripped.
Operations involving savesets tend to better preserve the file
attributes, even though the saveset attributes themselves can be
corrupted. (For tips and tools used to repair saveset attributes
when those are corrupted, please see the OpenVMS FAQ.)
The OpenVMS Wizard STRONGLY recommends you use the commands shown
in the BACKUP manual, as shown in the manual. For instance, the
OpenVMS Wizard would recommend always specifying /SAVE_SET on the
saveset parameter, even when this is not strictly necessary.
From the BACKUP/LABEL help text:
Specifies the 1- to 6-character volume labels for the magnetic
tapes to which the save set is written. If you do not specify
the /LABEL qualifier, BACKUP uses the first six characters of the
save-set name as the volume label of the first tape.
You received the new volume label because you told BACKUP to override
the label processing, and you defaulted the label specification.
BACKUP and the BACKUP$MANAGER environment are both involved tools,
and the BACKUP interface in particular can be quite intimidating
-- again, the OpenVMS Wizard would encourage review of the available
material. Additionally, the OpenVMS Wizard would verify the file
restoration path, and the ability to restore the needed data from
your data archives. (Without this testing, you cannot be assured
of access to your data -- either due to command error, hardware
error, BACKUP scheduling failures, or other unspecified problems.)
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