From: alan.nguyen@au.transport.bombardier.com
Date: Thu Jan 30 2003 - 19:02:07 EST
Thanks so much to these guys: James Sainsbury, Paul A Sand, Michael Polnick,
Robert M. Lang
As they clarify the timestamp entry in the /etc/vdumpdates file for me.
Below is the summary which I borrow the words from the guys.
When vdump finishes (END) it writes the time of the
beginning of the dump to /etc/vdumpdates .
This is correct, because a file could be modified during backup and
had to be dumped the next time with differential vdump.
vdump remembers the time stamp when it started and
only on successful completion actually updates the vdumpdates file
with that time stamp.
So a failed dump appears as a though a dump never happened
(or a dump is an atomic transaction.)
It has to be the time stamp at the beginning otherwise if a file is changed
after it has been dumped subsequent incrementals won't pick it up.
>From looking at my dump logs and comparing with /etc/vdumpdates,
the timestamp in /etc/vdumpdates seems to be the time the
dump starts. This is v5.1A, so maybe it's different on 4.0F.
The actual entry in /etc/vdumpdates doesn't get written until the
end of the dump, though.
My experience is: if the dump fails for some reason, the /etc/vdumpdates
file doesn't get updated.
The man page seems to be pretty clear on this:
-u Updates the /etc/vdumpdates file with a timestamp entry from the
beginning of the backup.
What this says is that if you start the vdump at 13:30 the dump occurs and
when the vdumpdate file is written, the entry will say 13:30. The keyword
is "from".
My question:
> OS = 4.0F
> It's a bit confusing that according to the man page of vdump that a command
> vdump -u is used to update the /etc/vdumpdates file with the timestamp entry
at
> the begining of the backup.
> However I found it opposite as the vdump -0vuf updates the /etc/vdumpdates
file
> with the timestamp entry at the END of each finished fileset backup. Can
anyone
> help clarify this ?
Alan.Nguyen@au.transport.bombardier.com
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