HPE EVA Storage

chache batteries failed

 
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michel legra
Occasional Contributor

chache batteries failed

Yesterday the cache batteries of my EVA 4000 failed and that's why I do not see any Vdisk and all my database services began to faile too, after I replaced the batterie I can see the Vdisk but I has some questions:

Why the crash of the cache batteries can affect the entire work of the EVA.

If I don't have other batteries, Is there some solituon to solve the problem.

7 REPLIES 7
Rob Leadbeater
Honored Contributor
Solution

Re: chache batteries failed

Hi,

Without cache batteries, there's potential for data loss in the event of a power cut - data in the cache would not be written to disk.

Someone at HP decided that it would be better to prevent data loss than to allow data access.

There is no solution to this as far as I'm aware.

Cheers,

Rob
michel legra
Occasional Contributor

Re: chache batteries failed

Thank you so much for you help, I have to by another batteries. I think they should let us decide what is most important, the cache data or the data in disk. The above depend on the particular bussines.
Bulent ILIMAN
Trusted Contributor

Re: chache batteries failed

actually the cache data is more important than your access to your data, cache holds the data which is acknowledged to host as written to disk but NOT WRITTEN yet, as you can understand only controllers know where the data in thecacheshould be written

having no cache batteries and facing an unexpected power off to EVA makez you lose all your data.

so do you prefer not to access your data for a while knowing you will be able to access whenever batteries are replaced or lose your data and need a backup to restore if you have?
Uwe Zessin
Honored Contributor

Re: chache batteries failed

Why not let the customer decide what is more important ?

Very often, storage arrays are also backed by an UPS in order to allow time for a clean shutdown.
He should at least be able to get at the data and move it somewhere else.
.
HenkW
Advisor

Re: chache batteries failed

Michel,

eva 4000 is a dual controller solution. In a case where a controller fails because of cache battery the remaing controller takes over and multipathing software should fail over to the remaining controller.

Regards
Uwe Zessin
Honored Contributor

Re: chache batteries failed

HenkW,

Michel's problem was that the batteries in *both* controller modules had failed.
.
Rob Leadbeater
Honored Contributor

Re: chache batteries failed

> having no cache batteries and facing an
> unexpected power off to EVA makez you lose
> all your data.

No, it makes you lose data in the write cache - not ALL your data !

As has been mentioned in these forums numerous times over the years, having both/all batteries fail is not uncommon, and it is not unusual for it to take a long time to get good replacements, particularly for the EVA3/5000.

This can be crippling for many businesses. As Uwe says, having the choice to operate without batteries would be nice...

Regards,

Rob