Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Programming
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Databases
Mail Systems
openSolaris
Eclipse Documentation
Techotopia.com
Virtuatopia.com
Answertopia.com

How To Guides
Virtualization
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Windows
Problem Solutions
Privacy Policy

  




 

 

Solaris Volume Manager Administration Guide
Previous Next

Overview of Checking Status of RAID-5 Volumes

You can check the status of RAID-5 volumes by looking at the volume states and the slice states for the volume. The slice state provides the most specific information when you are troubleshooting RAID-5 volume errors. The RAID-5 volume state only provides general status information, such as “Okay” or “Maintenance.”

If the RAID-5 volume state reports a “Maintenance” state, refer to the slice state. The slice state specifically reports if the slice is in the “Maintenance” state or the “Last Erred” state. You take a different recovery action depending on if the the slice is in the “Maintenance” state or the “Last Erred” state. If you only have a slice in the “Maintenance” state, it can be repaired without loss of data. If you have a slice in the “Maintenance” state and a slice in the “Last Erred” state, data has probably been corrupted. You must fix the slice in the “Maintenance” state first, then fix the “Last Erred” slice.

The following table explains RAID-5 volume states.

Table 14-1 RAID-5 Volume States

State

Meaning

Initializing

Slices are in the process of having all disk blocks zeroed. This process is necessary due to the nature of RAID-5 volumes with respect to data and parity interlace striping.

Once the state changes to “Okay,” the initialization process is complete and you are able to open the device. Until then, applications receive error messages.

Okay

The device is ready for use and is currently free from errors.

Maintenance

A slice has been marked as failed due to I/O or open errors. These errors were encountered during a read or write operation.

The following table explains the slice states for a RAID-5 volume and possible actions to take.

Table 14-2 RAID-5 Slice States

State

Meaning

Action

Initializing

Slices are in the process of having all disk blocks zeroed. This process is necessary due to the nature of RAID-5 volumes with respect to data and parity interlace striping.

Normally, none. If an I/O error occurs during this process, the device goes into the “Maintenance” state. If the initialization fails, the volume is in the “Initialization Failed” state, and the slice is in the “Maintenance” state. If this happens, clear the volume and recreate it.

Okay

The device is ready for use and is currently free from errors.

None. Slices can be added or replaced, if necessary.

Resyncing

The slice is actively being resynchronized. An error has occurred and been corrected, a slice has been enabled, or a slice has been added.

If desired, monitor the RAID-5 volume status until the resynchronization is done.

Maintenance

A single slice has been marked as failed due to I/O or open errors. These errors were encountered during a read or write operation.

Enable or replace the failed slice. See How to Enable a Component in a RAID-5 Volume, or How to Replace a Component in a RAID-5 Volume. The metastat command will show an invoke recovery message with the appropriate action to take with the metareplace command.

Maintenance/Last Erred

Multiple slices have encountered errors. The state of the failed slices is either “Maintenance” or “Last Erred.” In this state, no I/O is attempted on the slice that is in the “Maintenance” state. However, I/O is attempted on the slice marked “Last Erred” with the outcome being the overall status of the I/O request.

Enable or replace the failed slices. See How to Enable a Component in a RAID-5 Volume, or How to Replace a Component in a RAID-5 Volume. The metastat command will show an invoke recovery message with the appropriate action to take with the metareplace command. This command must be run with the -f flag. This state indicates that data might be fabricated due to multiple failed slices.

Previous Next

 
 
  Published under the terms fo the Public Documentation License Version 1.01. Design by Interspire