technical guide-recovering an array with raidrepair

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TECHNICAL GUIDE

Topic: Recovering an array with raidrepair.asp

Product: ATABoy / ATABeast / SATABlade / SATABoy / SATABeast / E18 / E60

Distribution: Public

Version: 2.0, created 5 September 2011

Nexsan RAID Repair Instructions

In the event of a RAID array failing due to multiple drive failures, the following procedure may be used to attempt recovery.

Please note that the success of the repair will depend on the health of the drives in the array and the ability to bring them back online and successfully read data from the drives. If you are in any doubt as to how to use this guide, please contact Nexsan Technical Support for assistance.

CAUTION: Raidrepair.asp should only be used under the guidance of Nexsan technical support. Incorrect usage may lead to data loss or corruption.

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Preparing for Raid Repair

1. Save a copy of your system event log Before attempting any repair, we recommend taking a copy of your system event log.

a. Navigate to System Information Event Log.

b. Click the link Download log/config dump as text.

c. Save the resulting log.dat file.

2. Do NOT replace any failed drives To recover an array, Raidrepair.asp needs access to as many original drives as possible. Removing drives can reduce the repair options and cause data loss or corruption.

3. Ensure that your firmware supports Raidrepair.asp Raid repair is only available with newer firmware versions. If you are running an earlier firmware build, please download the latest firmware for your product from our website: http://www.nexsan.com/support/latest‐firmware.aspx

To check your firmware version:

a. Navigate to System Information.

b. Check the Firmware revision or Build revision of your firmware.

i. If the firmware version is displayed as two groups of four characters separated by a period (xxxx.xxxx), it support Raidrepair.asp

ii. If the firmware version is displayed as two letters followed by two numbers (XXnn), the two numbers must be 41 or higher. If they are 40 or lower you MUST update your firmware.

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Running Raid Repair

1. Reboot the system We strongly recommend rebooting prior to the repair. If rebooting is undesirable, provided steps 2 and 3 are successful, you may be able to recover the array without a reboot.

a. Navigate to System Admin Reboot.

b. Select System Reboot, check the confirmation box, and click Execute NOW.

2. Attempt to bring failed drives back online

a. Navigate to Configure RAID Delete Spare.

b. Check the boxes to select all failed drives.

c. Click Delete Hot Spare.

d. At the prompt “Failed disk(s) deleted, disk(s) now unassigned”, click Back.

3. Check that all drives are online

a. Click Home and verify that all drives are now online.

4. Navigate to raidrepair.asp This is a hidden page, and must be loaded manually:

a. In your browser, edit the URL to read: http://<system‐ip‐address>/admin/raidrepair.asp

CAUTION: If any drives are still offline, they show as Missing, and the RAID Repair page displays a warning in red stating failed disks detected. If this occurs, contact Nexsan Technical Support before proceeding.

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5. Repair the array(s) The main RAID Repair screen is shown, detailing all RAID sets at the top of the screen, with recovery options for all repairable arrays shown below.

For each array you wish to repair:

a. RAID Repair will select the optimal set of drives to use in recovering the array. We do not recommend changing the selection unless you are directed to do so by Nexsan Technical Support.

CAUTION: Do NOT use any Incomplete drives except under specific instruction by Nexsan Technical Support. Use of these drives WILL result in data loss or data corruption and should only be used as a last resort. If any Incomplete drives are automatically selected, contact Nexsan Technical Support before proceeding.

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b. Check the Check to confirm box.

c. Click Repair Array.

d. At the “RAID repair in progress” screen, click Return To GUI.

6. Save another copy of the system event log After the array has been repaired, save your event log so the you have a record of the results.




7. Reboot the system After the raid repair has been completed, we recommend rebooting your system.

a. Navigate to System Admin Reboot.

b. Select System Reboot, check the confirmation box, and click Execute NOW.

8. Array now online Your array is now online and, if you have a hot spare available, is likely rebuilding onto that drive.

CAUTION: Do not assign any remaining drives as hot spares until your array has rebuilt and is again fault tolerant. If you do not have any spare drives, and your array is in a critical state, please contact Nexsan Technical Support for advice.

9. Verify LUN mappings and permissions In very rare cases (usually where LUN mappings have been changed since the first disk failure), old details may be loaded. This should be verified as follows:

a. Navigate to RAID Information Volumes and verify that LUN mappings are still correct for all volumes on the affected array.

b. Click the Next arrow for each volume on this array and verify that the appropriate host access permissions have been retained.

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Verify Data Integrity

1. Run host side data integrity tools as required Although your array is now online and usable, we recommend running file‐system and application data integrity checks to verify your data. Please refer to your operating system or application manuals for the tools to use.

2. Wait for array to return to a fault‐tolerant state Your array will most likely need to repair itself onto a hot spare drive. Depending on the size of your array and the load on your system, this may take anywhere from a few hours to several days to complete.

To monitor the progress of the rebuild:

a. Navigate to RAID Information Progress.

b. Wait for the “Rebuild” process to complete and for the Utility entry to read “‐“.

3. Run a Parity Scrub Once the array has rebuilt, or if a rebuild was not required, you will need to check the parity data on your array:

a. Navigate to RAID Information – RAID Array.

b. Confirm that your “Array status / health” now reads “RAID array is fault tolerant”.

c. Start a parity scrub:

i. Navigate to System Admin Verify Config.

ii. Select Parity Scrub and press Save Settings.

iii. Navigate back to System Admin Verify Config.

iv. Click Execute Verify Utility NOW.

v. Navigate again to System Admin Verify Config.

vi. Select Surface scan and press Save Settings.

d. To monitor the progress of the parity scrub:

i. Navigate to RAID Information Progress.

ii. Wait for the “Parity scrub” process to complete and for the Utility entry to read “‐“. Again, depending on the array, this may take anywhere from a few hours to several days to complete.

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4. Send System Event Log to support for verification With the repair complete, we recommend sending your system event log to Nexsan Support to verify that the process is complete.




d. Email this file plus the other event logs you downloaded to [email protected], quoting any case ID number you may have been given.

technical guide-recovering an array with raidrepair

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