Disk Enclosures

HP Smart Array 6402 Controller question


HP Smart Array 6402 Controller question



I've a couple of questions related to this controller.


Can it be operated without the batteries installed ? (the idea is using it inside a workstation that's turned off daily, and for various hours.. so I suspect that putting new batteries in the controller and memory module would be just a waste and they would die quickly. At the moment I've been forced to remove the controller since the batteries are so down that the card hangs during its own diags and it prevents the system from booting).


I've seen a couple of 3 pin plugs located next to the border of the card, on the side of the memory module slot. They are not documented in the pdf I've managed to find related to this controller, as are not documented the slot like connectors present on one side of the memory module, and on the top of the controller.


Are any of these allowing to give 3.3v power directly from the psu ( I would not dislike power while being operated, to make the cache working)?

If not, what is their usage ? (especially the 2 3pin ones)



Acclaimed Contributor

Re: HP Smart Array 6402 Controller question

The controller needs a battery in order to enable the write cache.


If the power is lost, the battery holds the cache contents until the power comes back (or the battery is empty), then it continues to write the data to the disks.


So you can see, power the cache from "normal" power source will not help in such case.


However, if you do a proper shutdown, the battery is not used while the power is off, because the cache is flushed to disk and empty.

Hope this helps!

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Re: HP Smart Array 6402 Controller question

Well, I'm relatively not so worried with a power loss since 1) it's for an hobby usage 2) the disks would be under an ups (ok the psu could fail, I know) and that's why I'm wondering if there's a way around the batteries. About doing a proper shutdown = not draining the batteries, still aren't they discharging while the system is powered off ?
Johan Guldmyr
Honored Contributor

Re: HP Smart Array 6402 Controller question

I suppose the batteries will drain when server is turned off, just like any other battery.

As far as this goes it looks like they ought to last 3 days: http://h18004.www1.hp.com/products/servers/proliantstorage/options/256bbwc/

Isn't it possible to simply disconnect the battery module?

Re: HP Smart Array 6402 Controller question

They can be removed more than disconnected (there's no cable to plug them... they instead rely on surface contacts on the board and on the memory module). What I'm trying to find out is if any of the feature connectors on the board or the ram module (all not documented in the official pdfs) is used to provide power not from a battery, when the controller is being diagnosed or such. I do think that every single connector is there for a reason (since it costs money to put them), and if one can serve this purpose I would be able to turn on the cache. Sure, it would be unacceptable for a serious use (I do agree about finishing to write the data in the cache after a big mess has been solved), but I think it would be acceptable for an home hobby (and I know I should have taken the 642.. that I think is supported by hpux too, instead of the 6402... but I'm a noob and noobishly thought that it was nicer a battery backed controller, especially since both were offered at the same price)

Re: HP Smart Array 6402 Controller question

I guess I've to ask again the controller doesn't allow the C8000 to boot at all with the batteries removed, it stops even before having access to the options with 2 error leds on the c8000 diag panel, and a blinking red emergency on the front. I've no big issues if the cache is turned off, but I would be able to still use that controller WITHOUT the onboard batteries. Anyone able to help ?