[comp.sys.ibm.pc] Files opened at the same time under Desqview

cwebster@rodan.acs.syr.edu (Chris Webster) (12/09/89)

I run Desqview 2.2 on an AT clone.  Something has been pestering me for a 
while now about DV: How does it handle files that are opened by different
applications at the same time?

On a network server drive, you'd run share in order to make sure nothing got
corrupt.  Should I run something like that on my machine?  (Share itself does
not seem to have any affect.)  It seems like a logical thing to do, but I
can not find any mention of it in my DV manual.

I mention this because I've been getting a lot of disk(hard drive) problems
when running DV.  I'm wondering if they are caused by programs using the same
file at the same time, or is my HD just getting flaky as it gets older?  (It's
probably the latter.)

rong@cwsys2..CWRU.Edu (Rong Chen) (12/09/89)

I don't find any problems when I open a ascii file in more than one windows.
But I don't know when the file is very large, and some of the windows(appli-
cation program) has to read in partial file into the window's designated
memery, while other window just changed the file (on disk), then what will
happen would probably messed up, DOS will lost track on the file's fragment
in most cases, when the first window tries to fetch other part of the file.

Hope this helps.

rc

kmcvay@oneb.UUCP (Ken McVay) (12/11/89)

In article <1500@rodan.acs.syr.edu>, cwebster@rodan.acs.syr.edu (Chris Webster) writes:
> 
> I run Desqview 2.2 on an AT clone.  Something has been pestering me for a 
> while now about DV: How does it handle files that are opened by different
> applications at the same time?

If memory serves correctly, it doesn't. If you change a file in partition "A"
and then access it from "B" you can expect FAT problems - think about it.

For that reason, I found it politic to bring DV down once a day (see 
previous message about running dual FD/Opus BBS systems) for maintenance -
a part of which was optimizing the drives with VOPT....while VOPT WOULD run
under DV, it would have been damned dangerous to do so, since both partitions
could access the drives.

Exercise reasonable care and your problems should end, and do any and all
system maintenance with DV down.

-- 
     "The number of  things in a given class is the class of all classes 
          that are similar to the given class." (Sprague de Camp)

Ralf.Brown@B.GP.CS.CMU.EDU (12/11/89)

In article <1035@oneb.UUCP>, kmcvay@oneb.UUCP (Ken McVay) wrote:
 >In article <1500@rodan.acs.syr.edu>, cwebster@rodan.acs.syr.edu (Chris Webster) writes:
 >> 
 >> I run Desqview 2.2 on an AT clone.  Something has been pestering me for a 
 >> while now about DV: How does it handle files that are opened by different
 >> applications at the same time?
 >
 >If memory serves correctly, it doesn't. If you change a file in partition "A"
 >and then access it from "B" you can expect FAT problems - think about it.

That's why you should run SHARE before starting DV.  SHARE will handle record
and file locking.  However, you won't get FAT problems, since the second
partition doesn't get a time-slice until the first finishes its DOS call, and
DOS updates the FAT before returning.  Scrambling the file is quite possible,
however (it's happened to me more than once).

 >For that reason, I found it politic to bring DV down once a day (see 
 >previous message about running dual FD/Opus BBS systems) for maintenance -

Me too.  My tape backup will run under DV so long as it's the only window, but
it works somewhat better outside DV (the verify has to reread lots of blocks
under DV because it missed them as they were whizzing by).

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