Raising Max SFM Volume Size Reported to System 7.5 Mac Users (120739)

SUMMARY

A registry flag controls the maximum volume size and free space reported by the Services for Macintosh (SFM) file server. Since System 7.5 now allows Macintoshes to support volumes up to 4GB-1 (0xFFFFFFFF), administrators may want to use this flag to help Macintosh clients if all clients are running System 7.5 and the SFM volume resides on a disk partition greater than 2018MB.

MORE INFORMATION

Pre-System 7.5 Macintoshes support volume sizes up to 2GB-1 (although tests have shown the actual limit to be around 2018MB). Because of this, SFM restricts the values it reports for total and free space on SFM volumes to 2018MB, when the actual size of the SFM volume's disk partition is larger.

System 7.5 can handle volumes up to 4GB-1, and you may find it useful to raise the maximum values reported for SFM volumes to this new limit.

WARNING: ALL Macs connected to the volume must be System 7.5; reporting a volume size greater than 2GB-1 to a pre-System 7.5 Macintosh crashes Macintosh Finder.

You can raise the maximum reported size for SFM volumes to 4GB-256 (0xFFFFFF00) by creating the SFM volume, then editing the registry entry:

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

Properties=xxxxx

by adding 262144 (0x00040000) to the number xxxxx.

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Stop and restart Macfile to make this change take effect on the SFM volume.

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