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From: carlos@io.UUCP (Carlos Smith)
Newsgroups: comp.sys.amiga
Subject: Re: Not a DOS disk
Message-ID: <376@io.UUCP>
Date: Fri, 11-Sep-87 15:46:26 EDT
Article-I.D.: io.376
Posted: Fri Sep 11 15:46:26 1987
Date-Received: Sat, 12-Sep-87 20:08:00 EDT
References: <373@io.UUCP> <2310@cbmvax.UUCP>
Reply-To: carlos@zapp.UUCP (Carlos Smith)
Organization: Interleaf, Cambridge, MA
Lines: 56

In article <2310@cbmvax.UUCP> daveh@cbmvax.UUCP (Dave Haynie) writes:
>in article <373@io.UUCP>, carlos@io.UUCP (Carlos Smith) says:
>
>> What I want to know is - Is Commodore going to release a fsck type utility
>> for hard disks? They had better - I expect most A2000 customers will have
>> hard disks, and none of the disk fixing programs I have seen are even smart
>> enough to handle a simple case where a file is deleted, but the directory
>> thinks it is still there. This is pretty basic. I'm surprised the validator
>> doesn't handle stuff of this type, much less that there is no OS utility to
>> do it.
>
>File is deleted but directory still thinks its there?  Really?  How so?  As
>far as I've ever been able to determine, the definition of a deleted file is
>a file that's been removed from the hash table of its directory.  So if the
>file still shows up in the directory, it hasn't been deleted.  If for some
>reason its data blocks have been marked as "free" in the BAM, that could be
>very unfortunate (though the validator would find this if it kicked in at
>the time).  It sounds like you want the DOS to specifically tag a deleted 
>block as being deleted instead of just being de-linked from it's parent.
>
>> 			Carlos Smith
>-- 
>Dave Haynie     Commodore-Amiga    Usenet: {ihnp4|caip|rutgers}!cbmvax!daveh

Welll, all I know is what the machine told me. I had a drawer that I attempted
to discard with the workbench (on my hard disk, unfortunately). The operation
failed with an "error 205, object not found". It wouldn't delete the directory
because it wasn't empty, and the only thing listed in the directory was a file
that it complained it couldn't find. I tried a simple 'C' program to unlink
the file directly, it also failed because it couldn't find the file listed
in the directory. The validator never seemed to be invoked, or to find it if 
it was. I wasn't up to writing a disk editor at the time, so eventually I 
tried diskdoctor on it (I had heard a rumor that it worked on hard disks) 
after selectively backing up all the other directories. It just trashed the
disk, and THAT invoked the validator. IT recommended diskdoctor, and after a
couple of cycles of this I reformatted. Interestingly, one thing the 
diskdoctor did was resurrect a whole bunch of files that HAD been deleted, 
and left them at the root. Now that I have Sectorama, I would poke around 
with that. In fact, I can't wait for it to happen again. Just let me at those
BAMs (whats a BAM?). I'll show it... No, not really, just kidding, honest.

So anyway, I hope this clarifies a situation that such a utility should deal
with. The directory still had the file listed as existing, but somehow when
it went to look it up the blocks were already deallocated?

I am posting this instead of replying by mail because there may be others 
interested in file system error recovery. Thanks for the reply, Dave. By the
way Sectorama (by David Joiner) IS on a Fish disk, number 102. This is 
something you will be glad to have if a disk bites it, provided you are up to
reading about what all those pointers and hash tables really mean (sorry, this
is new to me, I try to stick to graphics). But using this utility and with the
AmigaDos file system manual at hand you might be able to patch things up.
-- 
			Carlos Smith
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