RAID Battery replacement on MD3200 Disc Shelves

Question

Hello there

I have 2 disc shelves, MD3200. I have been advised by Dell that I need to replace the RAID batteries on both units.

I wondered if anyone has ever done this or are there any Dell instructions on how to go about it.

Each disc shelf only has one RAID card in each unit as one acts as a mirror of the other via the SAN software, but I am particularly concerned about knowing that the information in the cache has been written to the discs before the units are turned off while I replace the batteries.

Any thoughts or experiences anyone has would be greatly appreciated.

Kev

kevin_cambs_uk · Accepted Answer

Thanks Sam I have new batteries so will schedule a replacement, many thanks for your replies. Cheers mate

DELL-Sam L · Answer

Hello Kev,

So since you only have a single raid controller in your MD3200 here is what you will want to do to replace the battery.

Power off any host that is attached to your MD3200.
Once the host is powered off then wait about 3-5 minutes for all of the data that is stored in the cache of your MD3200 to be written to disk, then power off your MD3200.
Once the MD3200 is powered off then pull the raid controller out the back of the system & replace the battery.
Once the battery has been replaced then insert the raid controller back into the MD3200 & power on the MD3200.
Wait about 5 minutes for the MD3200 to boot up & come to a ready state.
Once the MD3200 has booted up & is at a ready state then power on all host that are attached to your MD3200.

Please let us know if you have any other questions.

kevin_cambs_uk · Answer

Hello Sam

many thanks for your response. Its greatly appreciated.

The error I got in the event viewer on the disc shelves was

RAID Controller Module cache memory recovery failed after power cycle or reset

The problem is that neither or the disc shelves were powered off or tampered with and they are on separate power supplies and a UPS and generator. The really strange thing was that both shelves did it at the same time.

So I am hoping that changing the battery will resolve it, but the scary part was making sure the cache was clear before the removal!

DELL-Sam L · Answer

Hello Kev,

I would say that since you had both batteries give the same message that unless it was doing a battery test or learn cycle on them that it sounds like the battery might need to be replaced. Without looking at the logs to confirm the error I would say that if you haven’t had that error message before then the battery may need to be replaced.

Please let us know if you have any other questions.

tswalker4505 · Answer

Is there any kind of config backup you need to do on the controllers before you shut off power? If the batter is taken out will is lose any array configuration before you put the new battery in?

Thanks.

DELL-Sam L · Answer

Hello tswalker4505,

No there is no need for a configuration backup, as your config is also stored on the drives in your MD3200. When the controller is inserted back in it will read the config from the drives if it is needed.

DELL|EMC Storage Forum

RAID Battery replacement on MD3200 Disc Shelves

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