A foreign drive doesn't happen due to a drive failure, but instead is caused by the Virtual Disk configuration information is different between the drive and the controllers. The controller and drives both contain information regarding the Virtual Disk configuration and one of those has changed. Now with clearing, you are telling the controller to Clear the VD config information from the drive and go with the controllers config information. Importing the foreign is doing the opposite, it is telling the controller to use the drives VD config information instead of its own. Now normally the rule of thumb is if the VD is still booting then you would clear the foreign, because if it is booting the information used is correct. If the VD isn't booting then the config data isn't correct on the controller and you would need to import the drives config information. Now with either of these it doesn't effect the data, just the configuration information. Now if these fail then you can still try retagging the VD which is deleting the VD then recreating it exactly the same without initializing the VD (which would delete the data), doing this will replace the VD configuration information on both controller and drives.
Thanks for the well-thought-out reply. I will try the clear since the import doesn't change the status of the disk. I did get a flurry of alerts at the same time from the iDRAC earlier this week:
An unrecoverable disk media error occurred on Disk 0 in Backplane 1 of RAID Controller in Slot 3.
Bad block medium error is detected at block 0x46651654 on Virtual Disk 3 on RAID Controller in Slot 3.
Bad block medium error is detected at block 0x46651e52 on Virtual Disk 3 on RAID Controller in Slot 3.
Disk 14 in Backplane 1 of RAID Controller in Slot 3 is not functioning correctly.
Virtual Disk 3 on RAID Controller in Slot 3 has failed.
Does that change the course of action that I should take, short of replacing the drive? I do have a spare SAS drive that I could send out to that location.
Since VD3 has failed and as far as I can see VD3 is RAID 0 level. I recommend you to make Chris's suggestions for Foreign drive. Because RAID 0 has no tolerance for data loss and will not be able to rebuild once a new drive installed. However, if you can access VD3 with the steps above. I recommend, you can take a backup of VD3 then you can consider using a new drive instead of disk 14. (it may have predictive failure)
Thanks, Erman. So after running the Clear operation, the list of foreign disks was gone but the bad disk still has the caution symbol on the status and it says ready. If I go to create a new virtual disk, disk 14 is not available. Only physical disk 15. There wasn't anything important on the RAID disk. It was more of a temporary file partition to help speed up the backup program I'm using. I might send out a replacement SAS which should fix the problem. Thank you very much for your input. Much appreciated! Bruce
DELL-Chris H
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July 24th, 2020 13:00
Humphs,
A foreign drive doesn't happen due to a drive failure, but instead is caused by the Virtual Disk configuration information is different between the drive and the controllers. The controller and drives both contain information regarding the Virtual Disk configuration and one of those has changed. Now with clearing, you are telling the controller to Clear the VD config information from the drive and go with the controllers config information. Importing the foreign is doing the opposite, it is telling the controller to use the drives VD config information instead of its own. Now normally the rule of thumb is if the VD is still booting then you would clear the foreign, because if it is booting the information used is correct. If the VD isn't booting then the config data isn't correct on the controller and you would need to import the drives config information. Now with either of these it doesn't effect the data, just the configuration information. Now if these fail then you can still try retagging the VD which is deleting the VD then recreating it exactly the same without initializing the VD (which would delete the data), doing this will replace the VD configuration information on both controller and drives.
Let me know if this helps.
Humphs
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July 25th, 2020 08:00
Hi Chris,
Thanks for the well-thought-out reply. I will try the clear since the import doesn't change the status of the disk. I did get a flurry of alerts at the same time from the iDRAC earlier this week:
Does that change the course of action that I should take, short of replacing the drive? I do have a spare SAS drive that I could send out to that location.
Cheers,
Bruce
DELL-Erman O
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3K Posts
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July 27th, 2020 00:00
Hello,
Since VD3 has failed and as far as I can see VD3 is RAID 0 level. I recommend you to make Chris's suggestions for Foreign drive. Because RAID 0 has no tolerance for data loss and will not be able to rebuild once a new drive installed. However, if you can access VD3 with the steps above. I recommend, you can take a backup of VD3 then you can consider using a new drive instead of disk 14. (it may have predictive failure)
Humphs
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July 27th, 2020 17:00