Raid Recovery Tips

Overview:

This Knowledge Base article describes a specific RAID reconfiguration; it describes how to re-configure the arrays using a Mylex Spanning feature to create a single 1.45 TB user volume spanned across Arrays 0 and 1 without a performance reduction. This procedure is data destructive for both user volumes. This procedure does not require the use of any special service tools. This procedure does not require system downtime, but the performance of the system will be affected significantly for about 10 minutes. System performance will also be slightly reduced for about 30 hours during the “background” creation of the redundant data on the arrays.

The standard configuration for a NAS 6000 base unit includes two user volumes, one with 723 GB and the second one with 768 GB. These volumes are on separate arrays. The NAS 6000 base unit has twelve 160 GB hard disks. This table describes the standard factory configuration.

In the procedure outlined below, an array spanning feature of the Mylex RAID controller is used to span the disk space for drives E: and F: into a large single E: drive. Spanning is limited to two arrays so the biggest possible user volume is 1.5 Terabytes. Alternative procedures have significant side effects (such as using the LDM to span volumes).

Procedure

This procedure is written for base unit configurations only and does not consider the use of previously connected expansion units.

Protect the User Data

This procedure assumes:

• The NAS 6000 is installed and running with Terminal Services access to the Server Desktop.
• This procedure assumes that the two user volumes on the base unit, (E: and F:) will be reconfigured.
• This procedure destroys all user data on drives E: and F:.

Procedure:

1. Logon to the NAS 6000 via Terminal Services. Enter the Administrator username and password when prompted.
2. On the server desktop, select “Start” → “Run” and enter the name of the hidden backup batch file C:\BackupMaxAttach6000.bat. Click on “OK”. This process takes about 10 minutes.
3. Backup all user data stored on drives E: and F: using an appropriate backup system. Run the Logical Disk Manager to Decommission the Existing User Volumes
4. On the server desktop, right click on “My Computer” and select “Manage” from the menu.
5. In the Computer Management window that appears, double click on the “Disk Management” Item under Storage. This starts the Logical Disk Manager (LDM) with three windows, the Console Tree, the Volumes List and the Disks window (in the lower right of the window)
6. In the Disks window, locate Disk2. Right click on the blue bar over the disk information area and select "Delete Partition" from the menu. Click on "Yes" when prompted.
7. In the Disks window, locate Disk3. Right click on the blue bar over the disk information area and select "Delete Partition" from the menu. Click on "Yes" when prompted.
8. Close the Logical Disk Manager and all other applications.
9. Search and modify the file gam2cl.ini located in the C:\Program Files\Mylex\Global Array Manager Client\ directory. Change setting for the line:
   ENABLE_SYSTEM_DRIVE_SPAN=0 to ENABLE_SYSTEM_DRIVE_SPAN=1
10. Start Mylex Global Array Manager Client application from Start > Programs menu.
11. Double click on the localhost item and login into Mylex controller administration window as Username: gamroot, no password.
12. Select the “Administration” Tab → “RAID Assist” → “Manual Configuration” → “New Configuration”.
13. Click and drag with the mouse Unused Disk Drives 0-0, 0-1, 0-2, 2-1, 2-2, 2-3 icons, one by one, and drop each into the most left empty place on the top row on the Disk Array A0.
    NOTE: the sequence and the position of the drives in the array is critical!
14. Click the “Add Array” button to create array A1.
15. Click and drag  with the mouse Unused Disk Drives 0-3, 1-0, 1-1, 1-2, 1-3, 2-0 icons, one by one, and drop each into the most left empty place on the top row on the Disk Array A1.
    NOTE: the sequence and the position of the drives in the array is critical!
16. Select “3”. Logical Drives tab.
17. Create Primary OS logical volume:
    Under RAID Level select “RAID 0+1”,
    Under Capacity, Logical type “7152”,
    Click the “Write Cache” radio button.
    Click the “Add Drive” button at the bottom left of the window.
18. Create Backup OS logical volume:
    Under RAID Level select “RAID 0+1”,
    Under Capacity, Logical type “14304”,
    Click the “Write Cache” radio button.
    Click the “Add Drive” button at the bottom left of the window.
19. Create User logical volume:
    Under RAID Level select "RAID 5",
    Under Capacity, Logical accept default size of “1527360”,
    Click the “Write Cache” radio button.
    Click the “Add Drive” button at the bottom left of the window.
20. Click the “Apply” button at the bottom right of the window.
21. Select “Yes” at the next window to proceed.
22. Type ”Yes” in the space provided and click the “OK” button. At this moment the Mylex RAID controller is being re-configured. The screen will seem to “freeze”, the MS Windows Clock icon will appear and all the drives in the enclosure will start blinking. That event may take few minutes.
23. Close and exit “Global Array Manager Client” application. When the Microsoft Windows Clock icon disappears, the system is ready to be used and user volumes can be created with the Logical Disk Manager (LDM). When in it, the empty space for volume creation will span all free space of the two arrays A0 and A1.

Run the Logical Disk Manager to Create a Big User Volume

1. On the server desktop, right click on “My Computer” and select “Manage” from the menu.
2. In the Computer Management window that appears, double click on the “Disk Management” Item under Storage. This starts the Logical Disk Manager (LDM) with three windows, the Console Tree, the Volumes List and the Disks window (in the lower right of the window)
3. In the Disks window, locate “Disk2”. Right click on the blue bar over the disk information area and select “Create Partition” from the menu. A Create Disk Partition Wizard will appear.
4. In the Create Disk Partition Wizard,
   • Use all of the space available on Disk2
   • Select "Quick Format"
   • Name the volume as desired
   • Use drive letter E:
   • Use the NTFS file system
   • Use the default block size

   • The volume creation and quick formatting will require about 10 minutes.

Special Considerations

1. The new volume will not be visible or usable (after the creation and formatting are complete) until the current Terminal Services session and Administrator login session has been ended. Close the LDM and logout user Administrator from the MaxAttach NAS 6000 server desktop. This action will also end the Terminal Services session. In the next Terminal Services session, the new volume will appear under My Computer and in the LDM.
2. At this time, the new large volume E: is available for use and it has a 1.45 Terabyte capacity. The RAID controller will initialize (create parity data) the arrays in less than 30 hours. During this background initialization, there is an impact on system response times and there will be visible disk activity even when no users are connected.