From:	CRDGW2::CRDGW2::MRGATE::"SMTP::CRVAX.SRI.COM::RELAY-INFO-VAX"  6-OCT-1989 17:21
To:	MRGATE::"ARISIA::EVERHART"
Subj:	Re: Vddriver and disk defragmenters

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Date: 	Fri, 6 Oct 89 15:35:53 EDT
From: wilts@CaVax.AB.CA (Ed Wilts)
Message-Id: <891006133553.3865@CaVax.AB.CA>
Subject: Re: Vddriver and disk defragmenters
To: info-vax@sri.com
X-St-Vmsmail-To: ST%"INFO-VAX@SRI.COM",WILTS

>>I bet that using this with a FILE DEFRAGMENTER product could
>>result in some really bad lossage.

[problems about moving files being used as a VD device deleted]

>       Wonder if any of the defragmenters can be told of
>classes of files that should (must) be excluded from their
>machinations? Since there are NO locks on the VD: container
>files, I don't see how they can possibly tell they are
>in use short of such a system. (There's nothing wrong
>with calling container files something.SYS, for example,
>if that will protect them.)
>Glenn Everhart

Of course I can't speak for all disk defragmenters, but the one we run (DEFRAG
from H & E Concepts in Denver) has 5 options for excluding files.  You can
exclude by File ID, UIC, extension, directory, or wildcard.  This means that it
is certainly possible to not move the files you are using as container files if
you can fit them into one of these categories (like naming them something.SYS
and then exclude *.SYS during your run).

        .../Ed                   (403) 234-1007
Ed Wilts                (Wilts%CaVax.AB.CA@UncaNet.Bitnet)
Canadian Occidental Petroleum Ltd., Calgary, Alberta, Canada