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From: harrow@exodus.dec.com (Jeff Harrow, NCSE LKG1-3/F16 DTN=226-7445)
Newsgroups: net.micro.mac
Subject: HFS Backup-RESTORE Review, and Apple HD20 \"Missing Space\"...
Message-ID: <4044@decwrl.DEC.COM>
Date: Sat, 5-Jul-86 17:54:49 EDT
Article-I.D.: decwrl.4044
Posted: Sat Jul  5 17:54:49 1986
Date-Received: Sun, 6-Jul-86 04:38:10 EDT
Sender: daemon@decwrl.DEC.COM
Organization: Digital Equipment Corporation
Lines: 89

Well, I finally got brave and restored my Apple HD20 from a full backup
using HFS Backup from PCPC (1-800-MACBUTT).

Why did I do this:  because I wanted to make SURE that this would work as
advertised; because I've been stuck with a particular folder, empty, which
I could NOT trash because, when I tried, it gave me a "Disk Error" alert; and
also because I've always been MISSING some space on my HD20 and really
wanted to get it back (whoever thought that 20 Megabytes wouldn't be
enough...).  Here is the problem:

The Finder's window showed 3,272K available, and a GetInfo on the root
folder showed 15,748K in disk for a total of 19,020K accounted for out of
an expected 20 megabytes; 980K missing!!  Now, while I expect the file
system, etc. to take up SOME room, .98 Megabytes??!!??  Seems
unreasonable to me.

So, I backed up my 15,748K of data onto 42 single sided floppys (average
374.9K per floppy), using the "check before using" and "check after using"
options in HFS backup.  Then, with floppys scattered over my desk, I said a
(temporary, I hoped) goodby to my hard disk and utilized the Hard Disk Test
program on the HD20 Startup floppy to DESTRUCTIVELY test the HD20 (hit a
Command/D at the normal screen to get the more interesting test screen -
but make sure the floppy is NOT write protected or you'll get a bomb when
it tries to write its report).

I let it go through its test (no hard or soft errors) and decided that I
wouldn't find out what had been going on with my wierd folder, so on with
the business of restoring the disk...

I wanted to fully reinitialize the disk to, hopefully, get rid of the last
vestiges of the un-deletable folder, and figured that the destructive
testing of the HD20 (which APPEARED to include an initialize phase) would
render it unreadable to the Mac and would bring up the Initialize dialog box
when the Finder attempted to mount it.  Well, I Quit from the Test program
and got the "...slightly damaged... Fix it?" dialog box which causes a
re-build of the desktop file; NOT what I wanted.   I thought I'd give it
another try so I said NO, did a Shutdown, and rebooted using the HD20 disk.

This time, when it went to mount the HD20, it did give me the "Initialize"
dialog box, and I said OK.

It initialized fine, but now, here's an oddity (and I'd like some input if you
have some idea of what's going on):  Immediately after Initializing my 20
Megabyte HD20, it said 0 Items, 32K in disk, and 19,139K available, for a
total of 19,171K accounted for ON A NEWLY INITIALIZED DISK, leaving 829K
unaccounted for!  For the record, the floppy under which I was running at
the time was utilizing FInder 5.0.  Any ideas where the missing .829
Megabytes are?

I then went through the HFS Restore-Entire operation (I had the forsight to
put HFS Backup on my HD20 startup disk), all 42 disks, and Yup, my hard
disk was back!

Now, what happend to my disk space?  Check this out:

                                     PRIOR TO BACKUP           AFTER RESTORE

In Disk                            15,748K                          14,813K
Available                           3,272K                           4,207K
                                   ----------------------------------------
Total                              19,030K                          19,050K

Difference from 
expected 20MB                         980K                             950K

OK, now the questions:

o I started with a total of 19,030K accounted for, and ended up with
19,050K accounted for...  Where did I pick up the additional 20K?

o I started with one ratio of InUse/Available, and ended up with quite
another ratio (to my advantage; I picked up 935K of Available space, with
the same number of files, and almost the same Total amount of space
accounted for).  While I'm quite happy to recover some useable space,
where did it come from?

o WHY is there still a .95 Megabyte difference between the total space
accounted for and the anticipated 20 Megabytes?

Well, while I have generated some questions on which I hope you can shed
some light, this review should also give users of HFS Backup a good feeling
that in the event of a real problem, they can, indeed fully recover their
files from the backup set (and if you DON'T have some form of backup set,
just you wait...).

Disclaimer:  I have NO connection with PCPC or Apple except as a usually
satisfied customer.

Jeff Harrow