XP256 shutdown

[Andre Braganca]

If I need to cut off the power supply of my datacenter how do I switch off my XP256 disk array ? Suppose I've already switched off the server which is using the disks.

[Dave Wherry]

Andre,
GOOD LUCK!!!
I have fought this battle with HP over the past few months. Their official position is that the XP should not be turned off and never, ever, ever, ever turned off by a customer. On the rare occasion that it needs to be turned off, a CE must do it.
In the XP256 Familiarization Guide there is a power down procedure. It is incorrect and could cause data corruption. HP is supposed to changing the documentation to say a customer can not power down.
I agree with them that the 48 hour battery backup for the cache should be adequate. They have told me that if a power outage extends beyond the 48 hours they can have a CE on-site, changing the batteries. They did not tell me where they keep charged batteries. One of my points is that if I have a major power outage and all of my hosts are safely shutdown, why do I need those disks spinning and drawing power from my UPS batteries. I'd rather save that power for my phone switch so we can keep in touch with customers. HP doesn't see it that way.
To make a very long story short, HP strung me along for about 3 months and then basically slammed the door shut on me. No power down procedure and don't try it yourself.

[Andre Braganca]

I must admit that I posted this message AFTER talking to HP support ! Their arguments just don't make any sense. It looks like they have some engineering problem with those disk arrays and the easiest solution is to keep the disks spining ...

In my humble opinion, the customer shouldn't have to call in a HP expert just to shut the power supply down. Look at EMC ! Great disks, great support, no mumbo jumbo. They have 2 "off" buttons: a red panic button and a green one which slowly shuts down everything.

Thanks for sharing your frustration with me, Dave. I wonder if you could elaborate on that 48 hour battery backup. Does that mean that the customer can cut off power during a short time ?

[Dave Wherry]

Andre,
You may or may not be able to shut off the power to your datacenter safely. Do you have a UPS or generator? Obviously the drives will continue to spin until those power sources are depleted. Then the drives stop and you need a CE on-site to restart the XP.
The on-board batteries will maintain the data in cache for up to 48 hours. If you had written data to the cache just prior to the drives stopping, that data may not have been destaged to the disks. Then the cache has to be maintained by those batteries. The 48 hours is just a guideline. I would not count on it.
If you are going to have a scheduled power outage schedule a CE to be on-site. They can "safely" shut it down while a customer would not be smart enough to do that.

[Patrick Gorman]

I don't believe that HP is calling for an 'expert' to shutdown the XP because it is a complicated manuever. I think what they are trying to do is limit liability over what could be possible data corruption if done incorrectly.

[Dave Wherry]

Patrick,
Yes that is the company line they gave me. I somewhat agree with them that it might be best to just let it shutdown when the batteries run out. However, they did publish a procedure in early versions of the XP256 Familiarization Guide that is incorrect. I believe that is where their true liability lies. I understand they have changed the guide. They have not sent me a new one though so I think they are still exposed.
Coincidentally, we had a power failure this past Monday. Power was out long enough that the batteries ran down and the XP shut down. Actually that was OK. Nothing was damaged. The real issue is that we, the customer, are not supposed to power it up either. When power was restored we still had to wait over an hour to get a CE on-site. He flipped 2 breakers in R1 and 2 toggle switches in the DKC. That's all it took to bring it up. Meanwhile our company was shutdown for 1.5 to 2 additional hours waiting for this. That is not acceptable. We'll be discussing it with HP shortly.

[Mark van Silfhout]

You can find the latest manuals at: http://www.hp.com/cposupport/manindex/hpsurestor19161_eng_man.html
In the latest Fam. Guide it has been corrected. It tells you "for planned power outage you should have a trained HP engineer on-site".
Regards,

Mark