[comp.sys.ibm.pc.misc] share.exe and large media

mart@momenta (Martin O. Gates) (09/02/90)

	I am running dos 4.01 on one of my machines and I get a warning at
boot time that I should load share.exe for large media.  When I look at the
manual entry for share I can find no justification for loading it because I
have large media.  Can anyone explain why I should load it or better yet
tell me why I should not?

Text of message:
WARNING! SHARE should be loaded for large media

I have a 386SX clone with a Conner 100Meg drive in one huge partition.

	Thanks,
	Martin O. Gates

belt@freyr.pttrnl.nl (Evert van de Belt) (09/04/90)

The same warning appears on my screen whilst booting up. I took a dive
in the user guide and there it said: "Nothing !!". So I took another
dive and this time into this network and somewhere it said that SHARE
should be loaded for DOS 4.01 to remain compatible with very old versions
of DOS like 1.**. I can't remember where I read it, but if you don't
use very old software, don't use SHARE, it will only fill precious
memory.

                                          Good luck,
                                          Evert van de Belt
  

cjp@beartrk.beartrack.com (CJ Pilzer) (09/05/90)

In article <1990Sep1.183023.24393@momenta>, mart@momenta (Martin O. Gates) writes:
> 
> 	I am running dos 4.01 on one of my machines and I get a warning at
> boot time that I should load share.exe for large media.  When I look at the
> manual entry for share I can find no justification for loading it because I
> have large media.  Can anyone explain why I should load it or better yet
> tell me why I should not?

The reason for running share is protect the FAT and the data on your hard disk
from corruption.  The usual way for recent programs to access dos files is 
through the use of handles assigned by dos.  In the first version of dos there
was no such service.  At that time, files were access through File Control 
Blocks (FCB).  File handles were introduced in ver. 2.0.  In order to stay
compatible with users of ver 1.0, some authors continued to use FCB's.  In
fact, SIDEKICK still uses them I think.  If one of these programs is run
in a partition larger than 32 megs. it will corrupt the FAT and make all
data in that partition unavalible.  Programming to prevent this damage is
included in SHARE.EXE along with other code for use with shared files.

If you just copy SHARE.EXE over into your root partition (or where you
keep COMMAND.COM), it will be automatically loaded when necessary without
any further action by you, when you boot the computer.

marshall@wind55.seri.gov (Marshall L. Buhl) (09/05/90)

belt@freyr.pttrnl.nl (Evert van de Belt) writes:

>The same warning appears on my screen whilst booting up. I took a dive
>in the user guide and there it said: "Nothing !!". So I took another
>dive and this time into this network and somewhere it said that SHARE
>should be loaded for DOS 4.01 to remain compatible with very old versions
>of DOS like 1.**. I can't remember where I read it, but if you don't
>use very old software, don't use SHARE, it will only fill precious
>memory.

And if you do happen to use an old program and don't have SHARE loaded, 
pray that you have good backups - it can trash your disk.

>                                          Good luck,

You will need it if you run without SHARE.

>                                          Evert van de Belt

--
Marshall L. Buhl, Jr.                EMAIL: marshall@seri.gov
Senior Computer Missionary           VOICE: (303)231-1014
Wind Research Branch                 1617 Cole Blvd., Golden, CO  80401-3393
Solar Energy Research Institute      Solar - safe energy for a healthy future

scjones@thor.UUCP (Larry Jones) (09/05/90)

In article <belt.652436461@freyr>, belt@freyr.pttrnl.nl (Evert van de Belt) writes:
> So I took another
> dive and this time into this network and somewhere it said that SHARE
> should be loaded for DOS 4.01 to remain compatible with very old versions
> of DOS like 1.**. I can't remember where I read it, but if you don't
> use very old software, don't use SHARE, it will only fill precious
> memory.

Allow me to reiterate once again -- SHARE is required for the old (DOS
1) FCB functions to work correctly on large partitions.  Although DOS
2.0 introduced handle functions which were intended to replace the FCB
functions, there are some cases where the FCB functions are much more
efficient than the handle functions so THEY ARE STILL USED IN SOME NEW
SOFTWARE.  If you have a large DOS 4 partition and you don't load
SHARE, sooner or later you WILL have to restore your disk from a
backup because some piece of software has trashed it.
----
Larry Jones                         UUCP: uunet!sdrc!thor!scjones
SDRC                                      scjones@thor.UUCP
2000 Eastman Dr.                    BIX:  ltl
Milford, OH  45150-2789             AT&T: (513) 576-2070
Yep, we'd probably be dead by now if it wasn't for Twinkies. -- Calvin

dhesi%cirrusl@oliveb.ATC.olivetti.com (Rahul Dhesi) (09/06/90)

In <442@beartrk.beartrack.com> cjp@beartrk.beartrack.com (CJ Pilzer) writes:

     In order to stay compatible with users of ver 1.0, some authors
     continued to use FCB's...  If one of these programs is run in a
     partition larger than 32 megs. it will corrupt the FAT and make
     all data in that partition unavalible.  Programming to prevent
     this damage is included in SHARE.EXE along with other code for use
     with shared files.

Would it be fair to say, then, that MS-DOS has a serious disk-
corrupting bug, and SHARE.EXE is the bug fix?  A program that goes
strictly through the MS-DOS system calls should *never* cause FAT
corruption if the operating system is working correctly.
--
Rahul Dhesi <dhesi%cirrusl@oliveb.ATC.olivetti.com>
UUCP:  oliveb!cirrusl!dhesi

toma@tekgvs.LABS.TEK.COM (Tom Almy) (09/07/90)

In article <156@thor.UUCP> scjones@thor.UUCP (Larry Jones) writes:
>In article <belt.652436461@freyr>, belt@freyr.pttrnl.nl (Evert van de Belt) writes:
>> [...] I can't remember where I read it, but if you don't
>> use very old software, don't use SHARE, it will only fill precious
>> memory.

>Allow me to reiterate once again -- SHARE is required for the old (DOS
>1) FCB functions to work correctly on large partitions.  Although DOS
>2.0 introduced handle functions which were intended to replace the FCB
>functions, there are some cases where the FCB functions are much more
>efficient than the handle functions so THEY ARE STILL USED IN SOME NEW
>SOFTWARE.  If you have a large DOS 4 partition and you don't load
>SHARE, sooner or later you WILL have to restore your disk from a
>backup because some piece of software has trashed it.

Which is why I wrote NOSHARE.COM, a TSR that causes any attempt to open
or create a file with FCBs to return "failure". This tiny program doesn't
cause problems with file sharing (which one tends to get with SHARE)
and should prevent against disk corruption. It also effectively tells you
about old programs that should be tossed.

Because Microsoft doesn't document what SHARE actually does, use
NOSHARE at your own risk (it does work for me). There might be something
else I should guard against but don't. As an endorsement,
Microsoft recommends *against* the use of NOSHARE, so I figure it has
got to be good :-).

section 1 of uuencode 3.16 of file noshare.com    by R.E.M.

begin 644 noshare.com
MZ0@`]`$`````"@"\FA_'!@4!F!^]_A^)+@<!_.@Z`+@`3,TA`````(#\#W0*`
M@/P6=`4N_RZ``+#_SUY86EL>CMNT)<TA'__FM#7-(8G8C,/#N@H`N``QS2'H>
M2@`'3D]32$%21>A1`.@\``M">2!4;VT@06QM>>@_`+@A`.C)_Z,D`8D>)@&ZB
M)`%2NH``4KH6`%+H40",R%"ZA`!2NB$`4NB7_^FK_UN*!S#D0U-0`<-86E.)=
MT^DA`+@-`.@)`+@*`.D#``$``*+&`;1`N0$`NL8!BQ[$`<TAPXG!B=J+'L0!;
3M$#-(<-;65]>XP:,V([`\Z3_XZ3_F
``
end
sum -r/size 53542/375 section (from "begin" to "end")
sum -r/size 4841/244 entire input file

Tom Almy
toma@tekgvs.labs.tek.com
Standard Disclaimers Apply

scjones@thor.UUCP (Larry Jones) (09/08/90)

In article <2363@cirrusl.UUCP>, dhesi%cirrusl@oliveb.ATC.olivetti.com (Rahul Dhesi) writes:
> [ about SHARE.EXE being required for large partitions ]
> Would it be fair to say, then, that MS-DOS has a serious disk-
> corrupting bug, and SHARE.EXE is the bug fix?  A program that goes
> strictly through the MS-DOS system calls should *never* cause FAT
> corruption if the operating system is working correctly.

No, I don't think so.  SHARE.EXE is an attempt to modularize DOS so
that you can save precious memory by not installing parts that you
don't need.  If you don't install a part that you do need, it trys
to install it itself and complains if it can't so that you know that
there's a problem.  If you chose to ignore the warning, then you
deserve whatever happens.

Mind you, I DO think they could have documented the whole thing a
lot better, and trashing the disk is a rather severe consequence.
On the whole, though, I prefer that to simply refusing to boot or
adding code to all of the FCB functions to check for invalid usage
which would bloat DOS and slow it down as well.
----
Larry Jones                         UUCP: uunet!sdrc!thor!scjones
SDRC                                      scjones@thor.UUCP
2000 Eastman Dr.                    BIX:  ltl
Milford, OH  45150-2789             AT&T: (513) 576-2070
It's like SOMEthing... I just can't think of it. -- Calvin

keithe@tekgvs.LABS.TEK.COM (Keith Ericson) (09/15/90)

In article <8110@tekgvs.LABS.TEK.COM> keithe@tekgvs.LABS.TEK.COM (Keith Ericson) writes:
In article <belt.652436461@freyr> belt@freyr.pttrnl.nl (Evert van de Belt) writes:
>I can't remember where I read it, but if you don't
>use very old software, don't use SHARE, it will only fill precious
>memory.
>
I just discovered (it may be documented in the manual, but you know how that
goes!) that WordPerfect's "Notebook" (database) won't start up properly if
share.exe is not running.

And Tom Almy informs me that their Printer Driver modification program won't
run if share _is_ running!

Go figure...

kEITHe