| Unfortunately, hard disks can and do fail. This alone is a very solid reason for ensuring that you have a well thought-out and practiced disaster recovery plan in place (see Chapter 5 for more information on using the Windows Backup utility). If your data was on a basic storage disk or a simple, spanned , or striped dynamic volume, you will have no other choice but to replace the disk and restore the data from the last backup. If you experience failure of a disk in a mirrored volume or a RAID-5 array, fault tolerance is in place and you will be able to recover your data. Recovering a Failed Mirrored Drive Should one of the drives in a mirrored set happen to fail, you will be provided with a graphical indication in Disk Management. The process to repair the mirror depends on whether or not the disk that failed was part of a mirrored set that contained the system or boot partition. If the failed disk did not contain the system or boot partition (only data), you can restore the mirror by following these steps: -
From within Disk Management, right-click the failed mirrored volume and select Remove Mirror from the shortcut menu. -
In the Remove Mirror dialog box, select the disk that is to be removed and click Remove Mirror. -
Confirm that you want to remove the mirror by clicking OK when prompted with a dialog box. -
Power down the computer, replace the hard disk, and restart the computer. -
Create a new mirrored volume using the previous mirrored disk and the replacement disk. If the failed disk contained the system or boot partition, then you can restore the mirror by following these steps: -
Determine which mirrored disk failed. If the secondary disk failed (the disk that contains the mirrored data), you can replace it as outlined previously. If the primary disk failed (the disk that contains the original data), you must proceed with these steps. -
Create a Windows 2000 boot floppy that contains a copy of the boot.ini file pointing to the secondary disk in the mirrored set. -
If you have another Windows 2000 computer available, copy the ntldr, ntdetect.com, and boot.ini files from it to a blank, formatted 3-1/2 inch floppy disk. You need to edit the boot.ini file as shown in Step 5 to reflect the location of your secondary drive. -
If you do not have another Windows 2000 computer available, copy the ntdetect.com file from the I386 folder on a Windows 2000 Setup CD-ROM to a blank, formatted 3-1/2 inch floppy. You also need to expand the NTLDR file from this same location by entering the following command from the command line: expand Ntldr._ Ntldr . -
Finally, create a boot.ini that looks something like this that points to the secondary drive in your broken mirror (for more help on working with ARC paths, see http://support.microsoft.com/default.aspx?scid=kb;en-us;Q102873): [boot loader] timeout=30 default=multi(0)disk(0)rdisk(0)partition(1)\WINNT [operating systems] multi(0)disk(0)rdisk(0)partition(1) \WINNT="Microsoft Windows 2000 Server" /fastdetect -
Use your boot disk to start your Windows 2000 computer. -
Remove and re-create the mirror as discussed in the previous procedure. Recovering a Failed RAID-5 Drive Recovering from a disk failure in a RAID-5 array is a fairly simple process thanks to the fault tolerance provided by the array. Remember that RAID-5 arrays can only provide fault tolerance for one failed disk, so be sure to replace the failed disk as soon as possible. While the disk is failed and not replaced , you will still be able to use the RAID-5 array; however, I/O performance will be severely degraded as the missing data will have to be re-created from the parity information. Again, you should replace a failed disk in a RAID-5 array as soon as you can by performing the following steps: -
Power down the server, if necessary. Replace the failed disk. Restart the server, if necessary. If the disk is hot swappable, rescan the disks. -
In Disk Management, right-click the failed RAID-5 set (it will be marked as Failed Redundancy) and select Repair Volume from the shortcut menu. -
When prompted, select the new disk you installed and click OK to begin the rebuilding process. |
