has anyone ever run into a dirty cache issue with a Equallogic SAN. Even after replacement of the controller cards in the Equallogic Storage Array fails offline with a dirty cache.

I have listed steps here on my blog to bring the SAN online again, however this is not the best solution as it continues to fail.


If you have any info on this please share.




If the steps you listed do not clear up the issue, you can also try "raidtool -P" (purges caches).

This type of issue is fairly rare, but is usually indicative of controller/hardware problems when the issue continues to return like this.

I really wouldn't recommend facing this issue on your own without assistance from Equallogic support, but seeing as this unit is EOL, it may be tough to get support on it. Are you trying to migrate data off of the system so that you can retire it?

  • Thanks for the feedback. I was able to use the steps in the link to turn the storage unit up again to offload the data. After changes the 2 controller cards this issue still persists. I am wondering at this point is it worth the time/money to replace all drives in this system and chance that the current ones are the problem. Or do we go the next step and seek a back-plane. Aug 19 '14 at 15:38
  • It's very unlikely that the hard drives are the source of the problem. I can entertain the idea of the metadata on the RAID LUN being corrupted to some degree (though I've never seen it, let alone in regards to this issue). If it's possible to create a full backup of the data, you may want to try performing a reset of the array before you go replacing more hardware. If you still see the same issue with a "fresh" RAID set and there are no hard drive failures, the problem is likely with the backplane (assuming you didn't manage to get a replacement controller with the same problem as before).
    – JimNim
    Aug 19 '14 at 19:45

update, after replacing both controllers, power supplies, (waste of money - all HDD's) it failed again and we replaced the back-plane with another and it has not failed

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