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From: potts@us.cc.umich.edu (Paul Potts)
Newsgroups: comp.sys.mac.system
Subject: Re: Backing up aliases
Message-ID: <1991Jun14.134340.12543@terminator.cc.umich.edu>
Date: 14 Jun 91 13:43:40 GMT
References: <1402@ssdintel.isc.intel.com> <4114@ux.acs.umn.edu> <1991Jun13.142519.20475@ux1.cso.uiuc.edu> <4122@ux.acs.umn.edu>
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In article <4122@ux.acs.umn.edu> oleary@ux.acs.umn.edu (Doc O'Leary) writes:

>
>I don't know about other backup programs, but Redux backs up *everything*
>(or at least it seems).  It backs up the window sizes, the location of the
>files and folders with the window, the window locations on the screen, etc.
>I've never checked, but I'd bet that the id's are saved as well.  When I did
>complete restore back when I was using 7.0b4 (after moving from a 40MB to a
>105MB internal) everything was EXACTLY as I left it, and the aliases had no
>problem opening the original.
>
Redux is very good, IMO.  I own it as well.  I was very impressed to find
that it ran under system 7 with no problems whatsoever.
I have tried all the other major backup utilities out there (at least, the
ones that were available two years ago) and Redux is the only one that never
gave me any trouble.  Diskfit was 2nd, and Fastback was the worst.

People don't need to worry about their backup program keeping the
exact file refnums for aliases to continue to work.  According to IM-6,

"Even if a file has been renamed or moved on a volume, the Alias manager
can find it quickly through its file ID. 

If the search by file ID or directory ID fails, fast search looks for the
target by name in the original parent directory.  This search locates the
target if its file or directory ID has changed but it still by the same name
in the parent directory (for example, if the target was restored from backup).
...
If the search by file ID or directory ID fails and if fast search cannot find
the original parent directory, it searches for the target by full pathname.
This search finds the target if it resides in the same location on the
volume but the directory ID of its parent directory has changed (for example,
if the entire parent was restored from backup).

If the search by full pathname fails, fast search attempts to find the
file by tracing partial pathnames up through all parent directories...
etc..."

(I-M 6, p. 22-7)

ResolveAlias will then update the alias record, so presumably if the file
was hard to find, it will be easy to find next time the alias is used.

People don't give Apple enough credit.  Y'all didn't seriously think a minor 
obstacle like changing the file refnum would stop the alias manager from
finding it, did y'all?

(you can run, but you can't hide...)
-Paul Potts-
potts@itl.itd.umich.edu