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From: del@thrush.mlb.semi.harris.com (Don Lewis)
Newsgroups: comp.unix.admin
Subject: Re: Why idle backups??
Message-ID: <1990Nov1.011429.6787@mlb.semi.harris.com>
Date: 1 Nov 90 01:14:29 GMT
References: <1990Oct24.210312.3271@cubmol.bio.columbia.edu> <27337@mimsy.umd.edu>
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In article <27337@mimsy.umd.edu> chris@mimsy.umd.edu (Chris Torek) writes:
>t24.151840.2
>Dump decides which files (including directories) to dump by checking
>the inode times (atime, mtime, ctime, although the ctime alone should
>suffice).

One feature that I think would be useful would be to have another time
field in the inode (wtime?), that would only be updated by write()
(and ftruncate?).  Write() would also update ctime, as would link(),
unlink(), utimes(), chmod(), and chown().  If only ctime is newer than
the the previous dump time, then only the inode itself and not the
file data would need to be dumped.  If wtime is newer than the previous
dump time, then both the inode and data would need to be dumped.  This
would reduce the amount of data that needs to be dumped if
{chown,chgrp,chmod} -R are used.  The downside would be that it would be
more difficult to locate the tape containing the latest version of a
file to be restored (and you might have to still chmod/chgrp/chown it).

chmod -R  B-(
-- 
Don "Truck" Lewis                      Harris Semiconductor
Internet:  del@mlb.semi.harris.com     PO Box 883   MS 62A-028
Phone:     (407) 729-5205              Melbourne, FL  32901