Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!apollo!vijay
From: vijay@apollo.HP.COM (Vijay Sundaram)
Newsgroups: comp.sys.apollo
Subject: Re: WBAK/OmniBack mod/create times
Keywords: backup archive wbak rbak omniback
Message-ID: <45570a6d.122ae@apollo.HP.COM>
Date: 30 Aug 89 15:17:00 GMT
References: <3188@wasatch.utah.edu>
Reply-To: vijay@apollo.HP.COM (Vijay Sundaram)
Organization: Hewlett-Packard Apollo Division - Chelmsford, MA
Lines: 35

In article <3188@wasatch.utah.edu> zeleznik%cs.utah.edu@wasatch.utah.edu (Mike Zeleznik) writes:
>Is there a good reason why wbak uses the mod time of a file instead of its
>create time for incrementals?  
>
>The problem is if you "cp -p" in from another machine, or tar stuff in, the
>mod times will stay as the original (which is usually what one wants, along
>with keeping the modes).  But now, in general, these "new" files won't get
>backed up til the next full save (unless the mod times happened to be
>in the right window).  I don't think this would happen with ctime.
>
>This seems kind of a big hole for people who move things around.
>
>I understand OmniBack uses mod times also (correct me if I am wrong).
>
>Is there a reason for not using ctime?  Thanks.
>
>Mike
>
>  Michael Zeleznik              Computer Science Dept.
>                                University of Utah
>  zeleznik@cs.utah.edu          Salt Lake City, UT  84112
>                                (801) 581-5617


OmniBack uses the modified time (dtm) *as well as* the time the
attributes were changed (dta).  When you do a "cp -p" the modified
time remains the same, the time of creation and use gets updated.  The
dta also gets updated.  Since OmniBack looks at whichever was updated
from {dta, dtm}, no undue penalty is incurred.

-- Vijay-- 
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Vijay Sundaram                      vijay%apollo.hp.com
Apollo Division of Hewlett-Packard  {decwrl!decvax, mit-eddie, attunix}!apollo!vijay
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