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From: iverson@cory.Berkeley.EDU (Tim Iverson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: UNIX more fragile than MS-DOS files?
Message-ID: <3890@zen.berkeley.edu>
Date: Tue, 22-Sep-87 09:36:59 EDT
Article-I.D.: zen.3890
Posted: Tue Sep 22 09:36:59 1987
Date-Received: Thu, 24-Sep-87 04:25:39 EDT
References: <174@westmark.UUCP-> <1822@watcgl.waterloo.edu>
Sender: news@zen.berkeley.edu
Reply-To: iverson@cory.Berkeley.EDU.UUCP (Tim Iverson)
Organization: University of California, Berkeley
Lines: 17

In article <1822@watcgl.waterloo.edu> smvorkoetter@watmum.waterloo.edu (Stefan M. Vorkoetter) writes:
>MS-DOS uses write through buffers.  When you read a sector, it will check
>if the sector is in a buffer, and read it from there if it is.  When you
>write a sector, it writes straight to the disk (AND the buffer).  The file
>will only be trashed if a crash occurs during the write.

Almost, but not quite.  If you reboot with files open, the directory entry
doesn't get updated (this happens when the file is closed, and since it
wasn't closed, it doesn't get updated).  All of the file is still on disk,
its just that DOS no longer knows where it all is.  Of, course, similar
problems will occur on UNIX systems if you just randomly reboot - its 
just that there's rarely ever a need to do so on a protected system.


- Tim Iverson
  iverson@cory.Berkeley.EDU
  ucbvax!cory!iverson