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3.50 3.51
WINDOWS
kbother
The information in this article applies to:
- Microsoft Windows NT Workstation versions 3.5, 3.51, and 4.0
- Microsoft Windows NT Server versions 3.5, 3.51, and 4.0
SUMMARY
FTedit.exe is a Windows NT utility developed by Microsoft Product Support
and included with the recent release of the Windows NT resource kit; it
can also be obtained directly from Microsoft Product Support. The utility
was designed to aid in the recovery of software RAID sets under Windows NT
in certain circumstances. This article discusses how FTedit.exe works and
how it can help you solve certain kinds of FT problems.
MORE INFORMATION
Windows NT stores information pertaining to disks, drive-letter
assignments, and RAID sets in the registry. The information is located in
the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\DISKS
In this key are one or more \Device\CdRomX values which hold information
on CD-ROM drive-letter assignments, as well as an Information value, which
is a REG_BINARY value, meaning it is data stored in a binary (rather than
ASCII) format. The information stored in this registry value can be
divided into data pertaining to hard drives and data pertaining to FT
sets.
For each hard drive on the system, Windows NT stores the following
information in the registry value mentioned earlier:
For each FT set on the system, Windows NT stores:
- The type of FT set (mirror, stripe, volume set, etc.)
- How many members the set has
- A pointer showing the location of each partition in the set
All of the information in the registry is put there by Disk Administrator.
All the information pertaining to drives and partitions is based upon
drive information that Disk Administrator obtained by making system calls;
this information is updated each time Disk Administrator is executed, so
when new drives are added, the DISK key will be updated. All information
pertaining to FT sets is put in when the FT set is created in Disk
Administrator or when the FT set is updated.
What FTedit.exe does is load the Information value from the DISK key,
interpret it, and then allow you to manipulate that value and write it
back to the registry. This is the ONLY thing that FTedit does; the utility
never touches or affects drive configuration. This fact puts limitations
on what FTedit.exe can do, including the following:
- FTedit cannot create FT sets. FTedit can manipulate the FT set
definition in the registry, but this is only part of what is involved
in creating a new FT set.
- FTedit cannot add definitions for real drives. The utility will allow
you to add dummy definitions that map to nonexistent drives, but only
Disk Administrator can add the definition of a real drive (this task
requires hardware information that FTedit does not have).
- FTedit has no effect on hardware RAID. This is because
hardware RAID sets are configured by a RAID controller and are
perceived by Windows NT as a single physical drive.
However, FTedit can help you in the following situations:
- Disk Administrator no longer recognizes your FT sets (perhaps because
you reinstalled Windows NT or ran emergency repair). FTedit can be used
to rebuild the FT set definition and allow the operating system to
access the already existing FT set.
- When you run Disk Administrator, you get error messages stating that
your disk configuration has changed (for example, as a result of
removing or swapping out drives on an existing system). FTedit can be
used to remove the descriptions of the nonexistent drives from the
registry, thus stopping the error message.
For additional information, please see the following article in the
Microsoft Knowledge Base:
Article-ID: Q131658
TITLE : Use FTedit.EXE to Recover Lost Fault Tolerant Disk
Configuration
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