topic EVA battery backup in MSA Storage

EVA battery backup

muruggan — Tue, 16 Mar 2010 17:01:57 GMT

We have EVA6k at the remote site. Suddenly there was some unplanned power outage. All the servers were shutdown including the SMA. i am not able to access the storage now, no batteries in the UPS too. Will there be battery backup in the EVA.

If so do we need to shutdown the EVA through OCP(incase if the storage is up with the battery backup)
please guide me

Re: EVA battery backup

Uwe Zessin — Tue, 16 Mar 2010 19:34:49 GMT

The EVA uses rechargeable batteries to protect unwritten data in its writeback cache memory, but those batteries are way too small to keep an entire EVA running.

If you do a planned power down it it recommended to shut down the servers first. This will close all databases and files. Then shut down the EVA from Command View EVA. This makes sure that that data in the writeback cache is sent to disk before the EVA shuts down.
In most cases the EVA also turns off the batteries so that they don't get drained without a need.

Re: EVA battery backup

Sheldon Smith — Wed, 17 Mar 2010 10:48:28 GMT

So, being an unplanned power outage, I presume everything was active at the time, therefore there would be data in the EVA cache waiting to be written to the disks. And, being an unplanned power outage, I presume power would be restored within a couple days.
Assuming they were charged properly prior to the outage, the EVA cache batteries are doing there job; data will finish being written once power is back up. Be sure to have all SAN-attached servers wait for the EVA and fibre switches to fully start before allowing them to start.

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