Microsoft KB Archive/131658

= Use Ftedit.exe to Recover Fault Tolerant Disk Configuration =

Article ID: 131658

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Server 3.5
 * Microsoft Windows NT Server 3.51
 * Microsoft Windows NT Server 4.0 Standard Edition

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This article was previously published under Q131658



SUMMARY
If you have a computer running Windows NT Server that is


 * configured for fault tolerant (FT) partitions (such as stripe sets with parity and mirror sets)

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 * the partitions are inaccessible and appear in Disk Administrator as type Unknown

you may be able to make them accessible again by using the Ftedit utility.

This utility is available in the second update to the Microsoft Windows NT Resource Kit (for Windows NT version 3.51) or you can obtain this utility at no charge from Microsoft Technical Support (MTS).

This article explains:


 * When to Use Ftedit
 * How to Avoid Having to Use Ftedit in the Future
 * How to Install Ftedit
 * What to Verify Before Using Ftedit
 * How to Recover Fault Tolerance Sets
 * How to Recover Advanced FT Sets: Stripe Sets with Parity
 * How to Undo Changes Made with Ftedit



When to Use Ftedit
WARNING: Incorrect use of Ftedit on a computer with intact and recognized FT sets can cause loss of access to those FT sets. For additional information on using Ftedit, see the Help file that comes with Ftedit.

You can try to recover access to your hard disk(s) by using Ftedit, if you lose access to FT sets in various situations, including the following:


 * After you replace a boot disk with a new installation of Windows NT Server on it (in a computer with at least two hard disks)
 * After you have problems with stripe sets
 * After you replace a member disk of a stripe set with parity
 * After you have problems with volume sets
 * After you run the emergency repair program with an emergency repair disk that does not contain the correct hard disk configuration information

NOTE: Although Ftedit allows you to create a mirrored drive (mirror), you should always re-create a mirror in Disk Administrator (instead of Ftedit) by first breaking the mirror, then reestablishing it.

How to Avoid Having to Use Ftedit in the Future
To recover easily from these problems in the future without having to use Ftedit, save your hard disk configuration information whenever you make a change, for example, when you add fault tolerance.

To save your hard disk configuration information using Disk Administrator:


 * On the Partition menu, click Configuration, and then click Save.

You can use this saved information to restore the configuration if it is lost.

To restore the saved information using Disk Administrator:


 * On the Partition menu, click Configuration, and then click Restore.

How to Install Ftedit
The following three files come with Ftedit:

  Ftedit.exe Ftedit.hlp Ctl3d32.dll

  NOTE: For Windows NT 3.51 you also need Msvcrt.dll.

To install these files, do the following:


 * 1) Create a directory called Ftedit.
 * 2) Copy the Ftedit.exe and Ftedit.hlp files to the Ftedit directory.
 * 3) Copy the Ctl3d32.dll file to your %Systemroot%\System32 directory.

What to Verify Before Using Ftedit
Before you use Ftedit, verify that the following conditions are met:

 Your computer has a stripe set, stripe set with parity, or volume set that is physically present (that is, it was created using Disk Administrator and all the necessary drives and partitions are still recorded on the disk), but is not recognized by Windows NT. Verify that FTDISK is started in control panel\devices. FTDISK is the driver used by NT to identify and access fault tolerant drives.  The following Windows NT Registry key must exist:

     HKEY_LOCAL_MACHINE\SYSTEM\DISK NOTE: If this key does not exist, Disk Administrator creates it automatically if you start it once and then click Exit on the Partition menu to quit.

However, when Ftedit is used to re-create a volume set, it first reads this DISK key as a starting base. If this DISK key is corrupted, it may prevent Ftedit from creating a recognized volume set. In this case, save the current DISK key, and then delete it (to prevent Ftedit from trying to use it as a base). This allows the volume set to be created and recognized. This should not be the first step used. Delete the DISK key only if Ftedit cannot create the volume set due to a corrupted DISK key. 

How to Recover Fault Tolerance Sets
If you replaced a member disk in a stripe set with parity, skip to the "How to Recover Advanced FT Sets: Stripe Sets with Parity" section.

To recover access to a fault tolerance set (except mirrored disks), do the following:

 Run Ftedit.</li> On the Edit menu, click Create FT Set, or click the Make FT Set button.</li> In the FT Set Type dialog box, select the FT set type you want to recover (Stripe Set, Stripe Set With Parity, or Volume Set), then click OK.</li> Add the partitions that are members of the FT set one at a time, in their original order.

NOTE: In most cases, partitions are added in the order listed from the top down (not in order of Partition ID) in the Partitions list. If you are unsure about the order, consult your system administrator. If you are still unsure, contact Microsoft Technical Support.

To add a partition, use the following steps:

<ol style="list-style-type: lower-alpha;"> In the Disks list, click the drive that contains the partition you want to add. This causes the Partitions list to display all the partitions on the drive.</li> To add a partition as an entry to the New FT Set Information list, double-click it.</li> Repeat steps a and b for each partition that you want to add.</li></ol>

NOTE: If you select an incorrect partition or if you make an error, click Cancel. If you Cancel, start again from step 2.

</li> To add a partition, use the following steps:After you add all partitions to the New FT Set list, verify that they are the correct partitions and that they are listed in their original order. On the Edit menu, click Save FT Set or click the Save FT Set button. This adds the newly created FT set to the FT Set Information list.</li> To add a partition, use the following steps:Repeat steps 1 through 5 for each stripe set with parity that has a member that you need to regain access to.</li> To add a partition, use the following steps:When you are finished, click Save Current Disk Key on the Registry menu (or click Save Changes to System on the Edit menu). This saves the modified information to the Windows NT registry.</li> To add a partition, use the following steps:Quit Ftedit, shut down Windows NT, and reboot.</li> To add a partition, use the following steps:Run Disk Administrator. If you correctly set up the FT set description, your FT sets appear correctly in Disk Administrator and you should be able to assign a logical drive letter to each set.

NOTE: If the FT sets are listed as type Unknown in Disk Administrator, start Control Panel, double-click the Devices icon, and make sure that Ftdisk (not Ftedit) is set to start on boot. If Ftdisk is started and the FT sets are still not identified, you may have missed a partition, added one out of order, or added an incorrect partition. To correct this problem, follow the steps in the "How to Undo Changes Made with Ftedit" section. Then repeat the steps in this section.</li></ol>

How to Recover Advanced FT Sets: Stripe Sets with Parity
WARNING: Follow the steps in this section only if the following two conditions are true for your computer:


 * A stripe set with parity is missing one member disk.

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 * Windows NT no longer recognizes the set.

To recover access to the set, perform the following steps:

<ol> Run Ftedit.</li> On the Edit menu, click Add Drive, or click the Add Drive button. Read the warnings and click OK to continue, if appropriate.</li> Double-click one of the partitions that is not missing from the stripe set with parity to select it. This adds a new disk entry to the Disks list that contains a single partition that is identical to the other partitions in the stripe set.</li> On the Edit menu, click Create FT Set, or click the Make FT Set button.</li> In the FT Set Type dialog box, select the FT set type you want to recover (Stripe Set, Stripe Set with Parity, or Volume Set), and then click OK.</li> <li>Add the partitions that are members of the FT set one at a time, in their original order. When it is time to add the partition from the missing drive, add the partition from the newly created drive instead.

NOTE: In most cases, partitions are added in the order listed from the top down (not in order of Partition ID) in the Partitions list. If you are unsure about the order, consult your system administrator. If you are still unsure, contact Microsoft Technical Support.

To add a partition to the stripe set with parity:

<ol style="list-style-type: lower-alpha;"> <li>Select the drive that contains the partition you want to add in the Disks list. This causes the Partitions list to display all the partitions on the drive.</li> <li>Double-click the partition you want to add. This adds an entry to the New FT Set Information list.</li> <li>Repeat this for each partition that you need to be add.</li></ol>

NOTE: If you select an incorrect partition or if you make an error, click Cancel. If you Cancel, start again with step 4 in this section.</li> <li>After you add all partitions to the New FT Set list, verify that they are the correct partitions and that they are listed in the correct order. On the Edit menu, click Save FT Set or click the Save FT Set button. This adds the newly created FT set to the FT Set Information list.</li> <li>Repeat steps 1 through 7 for each stripe set with parity that has a member that you need to regain access to. When you are finished, click Save Current Disk Key on the Registry menu. This saves the changed information to the Windows NT registry.</li> <li>Quit Ftedit, shut down Windows NT, and reboot.</li> <li>After you reboot, run Disk Administrator. If you correctly set up the stripe sets with parity description, your stripe sets with parity appear and are identified correctly in Disk Administrator and you should be able to assign a logical drive letter to each set.

NOTE: If the stripe sets with parity show up as type Unknown in Disk Administrator, you should run Control Panel, choose Devices, and make sure Ftdisk (not Ftedit) is set to start on boot. If Ftdisk is started and the stripe sets with parity are still not identified, you may have missed a partition, added one out of order, or added an incorrect partition. To correct this problem, follow the steps in the "How to Undo Changes Made with Ftedit" section. Then repeat the steps in this section.</li></ol>

This allows Windows NT to recognize the stripe set with parity. Windows NT then goes through the steps that are normally required when replacing a missing drive from a stripe set with parity. For additional information, see pages 551-552 in the "Fixing Mirror Sets and Stripe Sets with Parity" section in the Microsoft Windows NT 3.5 "Server System Guide," or refer to the chapter titled "Recovering Disk Configuration Information" on page 443 in the Microsoft Windows NT 3.5 "Workstation System Guide."

How to Undo Changes Made with Ftedit
Use the recovery method appropriate to your situation:

Method 1: Changes Not Saved to the Registry:

If you created any FT sets, added extra drives, or made other changes with Ftedit, these changes are not written to the registry until you click Save Current Disk Key on the Registry menu. Therefore, you can prevent the changes from being written to the registry if you do not save your changes and do either of the following:

- On the Registry menu, click Reload Current Disk Key. This abandons your changes and reloads all FT information from the registry.

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- Quit Ftedit.

Method 2: Changes Saved to the Registry:

In this case, the previous (old) configuration information can be recovered and used to replace the current information by doing the following:

WARNING: Using the 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 the Registry Editor can be solved. Use this tool at your own risk.

<ol> <li> Run RegEdit32 (Regedt32.exe) and locate the following key:

<pre class="fixed_text">        HKEY_LOCAL_MACHINE\SYSTEM\OLDDISK1 NOTE: If you run Ftedit more than once, there may be more than one OLDDISKx key. You generally should select the key with the lowest number in place of "x" in "OLDDISKx", as this will be the backup key created the first time you run Ftedit. </li> <li>On the Registry menu, click Save Key to save this key to a file.</li> <li>Select the key SYSTEM\DISK.</li> <li>On the Registry menu, click Restore to restore the previously saved key.</li> <li>Shut down your computer and restart Windows NT.</li></ol>

Additional query words: prodnt raid raid5 ntfaqset

Keywords: kbhardware kbhw kbtool KB131658

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