[WinMac] Macs and 2G+ NT volumes

Peter Gunn(pdg1[at]cornell.edu)
Mon, 23 Nov 1998 08:57:59 -0500

"Michael Kulyk @ MACSPECTRUM" <kulyk@macspectrum.com> wrote:
>>1. When the 8GB volume on the NT 4, service pack 3 or 4, server is
>>opened by a Mac, the finder only shows 1.9GB as being available. Will
>>Appleshare Client 3.8.1 fix this? If not, what will?

Then Graeme Challis <g.challis@bendigo.latrobe.edu.au> wrote:
>could it be that the Mac trying to access this volume is running system
>software prior to version 7.5? I believe Sys 7.1 & earlier have a 2gb limit
>to the size volume it can address. Upgrading to Sys 7.5 or better should
>fix this.

Unfortunately it won't fix the fact that NT 4.0 still thinks that the
Mac can only read volumes 1.9G or smaller.

The problem is actually relatively cosmetic in nature -- 1.9G will
appear as the ammount left until there really is less than that ammount
left on the server.

However, if you're particular about the number being accurate, and
you're willing to futz around with the Registry, I'd recommend referring to
http://www.macwindows.com/servtips.html#MacNTtips . I quote
this particular subject below in its entirety (I believe MacWindows is
largely quoting from a Microsoft support page on the same topic):

-------------------
Microsoft Windows NT Server 3.5, 3.51, and 4.0 --
   Macs can only see 2 GB of bigger Services for Macintosh volumes.

Services for Macintosh volumes residing on the NT server that are
2 GB-4 GB in size can sometimes only be seen by Macs as 2 GBs in
size. Though not actually a bug, the problem is caused by the way
Microsoft configured Services for Macintosh; Prior to system 7.5,
Mac OS did not support volumes bigger than 2018 MB (just under 2 GB,
which is 2048 MG). Some versions of Services for Macintosh defaults
at restricting the values it reports for total and free space on
SFM volumes to 2018 MB, when the actual size of the SFM volume's
disk partition is larger.

System 7.5 raised the maximum volume limit to 4 GB, and System 7.5.2
raised it to 2 terabytes. However, 4 GB is the biggest volume size
for which the AFP network protocol will report correct total and
free space of a network volume. However, Macs can mount larger
network volumes &emdash; the just won't see the correct totoal and
free space figures. So, you can mount a 30 GB volume, but the Finder
might report "4 GB volume, 4 GB used, 4 GB free space."

To increase the 2 GB volume limit in NT Server, the NT Services
registry flag must be edited to raise the default 2018 MB maximum
volume size. You'll need to update Mac clients with very old System
software to at least System 7.5, or the Finder will crash when trying
to mount the SFM volume.

A registry flag controls the maximum volume size and free space
reported by the SFM file server. You can raise the maximum reported
size for SFM volumes to 4 GB-256 (a flag value of 0xFFFFFF00) by
creating the SFM volume, then editing the registry entry.

1. Use the Registry Editor (Regedt32.exe) to access the registry
entry at:

HKEY_LOCAL_MACHINES\System\CurrentControlSet\Services\MacFile\Parameters\Volumes
\<VolumeName>

Properties=xxxxx

2. Add 262144 (0x00040000) to the number xxxxx.

3. Stop and restart MacFile to make this change take effect on the
Services for Macintosh volume.

In Windows NT 3.51, you can change this value globally to enable all
volumes to be 4 GB (or more). To do this, add bit 0x10 to the
following section of the registry and every
volume will be 4 GB enabled:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MacFile\Parameters

ServerOptions: REG_DWORD: 0x13

NOTE: The ServerOptions value has a default value of 0x03. After
adding 0x10 to 0x03, the result becomes 0x13. After making this change
every volume will be 4 GB enabled.

Users registered at the Microsoft's tech support site can access a
similar article on this topic, Knowledge base article number Q120739.

Todd Parkhill points out that Thursby System's DAVE client correctly
displays the free space of mounted volumes (50 GB of free space is the
largest he's seen.) DAVE implements the Microsoft SMB file sharing client
on Mac OS. It does not use the AppleShare client (AFP), and does not
access Services for Macintosh, but accesses the Windows file server
on NT.

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This archive was generated by hypermail 2.0b2 on Mon Nov 23 1998 - 06:00:58 PST