David,
I'm assuming you mean 'bpduplicate' runs sequentially through the BID
file. From what I can tell, you can only give a single BIDfile to a
'bpduplicate' command.
I can easily see the 'race condition' problem if I have run multiple
bpduplicate commands, each with its own BID file. But what I'm asking
about is with regards to an individual instance of bpduplicate; does it
optomize the duplication process with regards to the BIDs listed in the
BID file its given, or does it simply dup the first image listed in its
BID file, then the second, then the third, and so on without any regard
to the media the images are on or the file number of the images on each
tape? So given a list of backup IDs, does bpduplicate group them by
the media they reside on and then sort the groups by the image's file
number on that media? I'm guessing your answer to that is going to be
"No it doesn't." (though personally, I think it should)
Oh, and I agree that grouping BIDs by media is the most efficent way
to do things. I'd also add sorting the BIDs in each group by file
number. I had started working on a routine to generate such an grouped
and ordered BID file but then wondered if Veritas has already included
such optimization in the 'bpduplicate' command. Guess not.
Anthony J Guzzi
Systems Administrator
Aviva Life Insurance Company
108 Myrtle Street North Quincy MA 02171
--- David Chapa <david.chapa AT adic DOT com> wrote:
> Sequential...It takes the first bid file then the next, etc.
>
> So depending on how many bpdup's you have running with bid files you
> could find yourself in a race condition for source tapes.
>
> Ex. Source Tape A00001 contains backupid_083038202...and
> backupid_099908800
>
> If your bid file1 has the 1st image in it and bid file2 has the second,
> you will "wait" potentially for the first to complete before the second
> will have an opportunity to run.
>
> That's why I like to sort them by Media ID. In my opinion it's the most
> efficient way to duplicate the images.
>
> David A. Chapa * Technical Advisor, Technical Marketing * ADIC *
> 720.249.5836 * david.chapa AT adic DOT com
>
> Pathlight VX - Integrated Disk-to-Tape Backup - http://www.adic.com
>
>
> -----Original Message-----
> From: veritas-bu-admin AT mailman.eng.auburn DOT edu
> [mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu] On Behalf Of Anthony
> Guzzi
> Sent: Wednesday, February 25, 2004 6:42 AM
> To: Veritas User List veritas-bu
> Subject: [Veritas-bu] 'bpduplicate' and use of a BID file
>
> I'm curious as to how intelligent 'bpduplicate' is with regards to it's
> use with a BID (BackupID) file. If I had a file of BIDs and these BIDs
> were scattered among more then one tape, is 'bpduplicate' intelligent
> enough to sort the BIDs by tape and then by file number on each tape;
> or does it simply duplicate them in the order they are listed in the
> file?
>
> For example, assume I have a file with a list of six images: the first
> and third image reside on tape A00001, the second and sixth image reside
> on tape M12001, and the fourth and fifth reside on tape NH0033 with the
> fifth one preceeding the fourth one on the tape. Also assume all copies
> will be (can be, and we want then to be) written to the same tape.
> Is 'bpduplicate' smart enough that it will reorganize the image list
> into "first, third, second, sixth, fifth, fourth" (or something similar)
> so that each source tape is only loaded once and only advanced until
> done; or would it start loading and unloading tapes and rewinding tapes
> in order to duplicate the images in the order specified in the BID file?
>
> Anthony J Guzzi
> Systems Administrator
> Aviva Life Insurance Company
> 108 Myrtle Street North Quincy MA 02171
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