Users Guide

1. Back up the degraded virtual disk onto a fresh (unused) tape drive.
• If the backup is successful — If the backup completes successfully, then the user data on the virtual disk has not been damaged.
In this case, you can continue with step 2.
• If the backup encounters errors — If the backup encounters errors then the user data has been damaged and cannot be
recovered from the virtual disk. In this case, the only possibility for recovery is to restore from a previous backup of the virtual disk.
2. Perform a Check Consistency on the virtual disk that you have backed up onto a tape drive.
3. Restore the virtual disk from the tape drive onto healthy physical disks.
Cannot Create A Virtual Disk
You may be attempting a RAID configuration that is not supported by the controller. Check the following:
• How many virtual disks already exist on the controller? Each controller supports a maximum number of virtual disks.
• Is there adequate available space on the disk? The physical disks that you have selected for creating the virtual disk must have an
adequate amount of free space available.
• The controller may be performing other tasks, such rebuilding a physical disk, that must run to completion before the controller can
create the new virtual disk.
Related concepts
Number Of Virtual Disks Per Controller
A Virtual Disk Of Minimum Size Is Not Visible To Windows
Disk Management
If you create a virtual disk using the minimum allowable size in Storage Management, the virtual disk may not be visible to Windows Disk
Management even after initialization. This occurs because Windows Disk Management is only able to recognize extremely small virtual
disks if they are dynamic. It is advisable to create virtual disks of larger size when using Storage Management.
Virtual Disk Errors On Systems Running Linux
On some versions of the Linux operating system, the virtual disk size is limited to 1TB. If you create a virtual disk that exceeds the 1TB
limitation, your system may experience the following behavior:
• I/O errors to the virtual disk or logical drive.
• Inaccessible virtual disk or logical drive.
• Virtual disk or logical drive size is smaller than expected.
If you have created a virtual disk that exceeds the 1TB limitation, you must:
1. Back up your data.
2. Delete the virtual disk.
3. Create one or more virtual disks that are smaller than 1TB.
4. Restore your data from backup.
Irrespective of whether your Linux operating system limits the virtual disk size to 1TB, the virtual disk size depends on the version of
the operating system and any updates or modifications that you have implemented. For more information on operating system, see
your operating system documentation.
Problems Associated With Using The Same Physical Disks
For Both Redundant And Non-Redundant Virtual Disks
When creating virtual disks, you should avoid using the same physical disks for both redundant and nonredundant virtual disks. This applies
to all controllers. Using the same physical disks for both redundant and nonredundant virtual disks can result in unexpected behavior
including data loss.
NOTE:
SAS controllers do not allow you to create redundant and nonredundant virtual disks on the same set of physical
disks.
154 Troubleshooting