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From: gwyn@brl-tgr.ARPA (Doug Gwyn )
Newsgroups: net.unix
Subject: Re:  file archiving
Message-ID: <715@brl-tgr.ARPA>
Date: Thu, 15-Aug-85 05:44:24 EDT
Article-I.D.: brl-tgr.715
Posted: Thu Aug 15 05:44:24 1985
Date-Received: Sun, 18-Aug-85 04:52:24 EDT
References: <445@brl-tgr.ARPA> <49600006@convexs>
Organization: Ballistic Research Lab
Lines: 16

> I hope you're doing this single user!  Otherwise, it seems like you'd
> run the risk of having race conditions with someone updating files while
> you're doing the archiving/deleting.  Perhaps not all that likely, but
> Murphy's been working overtime here lately.

I know of no way to avoid that possibility, other than as you say
being single-user.  The only danger in the race would be that a file
being updated might get put on the tape then removed, so that the
archival copy would be corrupted.  You will note that I did make a
single temp file containing the names and used it for both archiving and
deleting, to make sure that nothing could get deleted that wasn't on
the tape.  (I forgot to say that one should remove this temp file
(list of filenames) when he is done; presumably if one does this
activity on a regular basis he would want to keep the file list on-line
so that one could easily find which tape had the deleted file that
one later needs restored.)