Corrupt Partition M...
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Corrupt Partition Map

Active Member Customer

I am using SoftRAID 5.5.5 on a Thunderbay with four drives configured as RAID 5. This volume holds my user directories connected to an iMac.

I have Drive Genius 4 and use Drive Pulse to run regular checks on all my volumes and this has been fine until today when it reported an a problem with the Partition Map. The volume has been working without issue for some time but Disk Utility also reported a serious partition map problem so I immediately made a back up, reinitialised all the drives with SoftRAID and recreated the volume. Disk Utility still reported the problem even though this was newly created.

Am I correct in assuming that applications such as Disk Utility should correctly report the status of the Partition Map or does using SoftRAID cause the problem. Running a Volume Structures Test in Drive Genius reports no issues with the volume itself.

I should add that even Disk Utility reported no problems with the Partition Maps on the individual drives.

Any thoughts on this will be gratefully received.


Topic starter Posted : 26/11/2016 1:21 pm
Member Admin

If you are running 10.12, this is a known bug with Disk Utility.

Here is a note we wrote about this:

It seems that the next Sierra update should fix this bug.

BTW: In our experience, the best tool to manage directory damage is Disk Warrior, which does not try to repair them, it recreates the directory and replaces it. We have seen no other tool as effective.

Posted : 28/11/2016 10:35 am
Active Member Customer

Thanks, I found the article shortly after I posted. As it happens I did run DiskWarrior and was rather puzzled to that Disk Utility still reported an error. I wonder how Drive Genius checks the partition map is it was Drive Genius that initially flagged a problem.

May I add a word of advice to everyone, just in case they don't already do this. Prior to reinitialising my drive I performed a full backup with carbon Copy Cloner. During the process of restoring, CCC had read errors on a block of files that happened to be some photographs. Fortunately I also backup using Qrecall to a Drobo and with Arq to Amazon Cloud Drive so it was easy to get those files back. The moral is NEVER rely on a single backup. Always have at least two backups preferably using different software/drives etc

Topic starter Posted : 28/11/2016 3:19 pm