MacMini Mirror RAID degradated, 2nd slice failed

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VictorEspina Author

Level 1

4 points

MacMini Mirror RAID degradated, 2nd slice failed

I have a Mac Mini Server Late 2012, with the following specs:

- 2.3 GHZ I7

- 10 GB RAM (1x2 GB, 1x8 GB)

- Dual 1 TB HD 5.400 RPM

- OSX Maverick 10.9.5

- Mirror RAID

Apparently an error with OwnCloud caused the disk to get almost full. I found the problem, deleted the files and then ran disk utility and, for my surprise, I found the raid hd (serverhd) marked as "degradated" and the 2nd disk marked as "failed":

Running diskutil on terminal confirms that the 2nd slice as "failed":

My questions are:

1. Does the failed status on disk1s2 means that the disk PHYSICALLY failed or that the data in the disk doesn't match with the one in the 1st disk?

2. If this is a data failure, how can I rebuild the data in the 2nd disk? By selecting the failed disk in disk utility and hitting Rebuild?

TIA

Victor Espina

Mac mini, OS X Mavericks (10.9.5), Late 2012

Posted on Jan 20, 2015 6:50 AM

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Answer 1

VictorEspina Author

Level 1

4 points

Jan 21, 2015 4:11 AM in response to VictorEspina

I just checked the SMART status of the faulty drive and it says "VERIFIED". Does this means that the drive is physically OK ?

Victor

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Answer 2

Eric Root

Level 10

684,033 points

Jan 21, 2015 8:37 AM in response to VictorEspina

Try using Disk Utility to reformat the failed drive. Erase, then Mac OS Extended (Journaled), click Option/GUID, and then apply.

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Answer 3

VictorEspina Author

Level 1

4 points

Jan 21, 2015 9:11 AM in response to Eric Root

Eric, do you mean that I should be able to format the 2nd drive even when it is associated with an active RAID set? If so, after the drive is clean, the next step would be to select the faulty slice in the RAID set and press "Rebuild" button?

Victor

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Answer 4

VictorEspina Author

Level 1

4 points

Mar 28, 2015 6:03 PM in response to VictorEspina

I finally solved this issue:

1. Made a full copy of server's HD in a external disk using CCC

2. Changed boot drive to use the external disk. In theory, this was not needed but I prefered to boot from a different disk just in case.

3. Once booted from the external disk, when to Disk Utility and "demote" the failed disk from the RAID array.

4. Using Disk Utility, I reformated the failed disk and added again to the RAID set (to do this, select first the RAID set and then drag & drop the disk from the left panel)

5. Once the disk was added to the RAID set, I pressed Rebuild and waited until de RAID set was rebuilt.

6. Then I set the HD as the boot drive and restarted the server

Thanks all for your help on this.

Victor Espina

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