rp7410 cell removal

[bagek]

I have a rp7410 with 2 cell boards with 2 cpu's each running HPUX 11.23. I want to remove 1 cell board. I assume that should be cell 0. When I tried that the system would not boot. Any ideas? thanks.

[Matti_Kurkela · Accepted solution]

> I want to remove 1 cell board. I assume that should be cell 0.

Is this just an assumption or have you actually checked the hardware configuration?

Things to check before deciding which cell to remove:

• Do you have one MP CoreI/O or two? If just one, which cell board is it connected to, i.e. which MP slot is populated? If you want to run the system with only cell #1 present, the bottom MP CoreI/O slot must be populated.
• What is the hardware path of your system disk(s)? The first digit of the hardware path will identify the cell board it is connected to. Of the 4 local disk slots, the bottom ones are connected to cell 0, and the top ones to cell 1.
• If a removable media drive is installed (either a DVD disc drive or a DAT tape drive) is installed, it is always connected to cell 1. (I guess this might be your reason to choose cell 0 for removal?)
• You will also lose the use of 8 PCI slots when you remove a cell. Have you checked that your hardware configuration does not depend on some card that is controlled by the cell you wish to remove? If it does, you will have to move the card to a slot that is controlled by the other cell, or otherwise change your configuration to remove that dependency.

If the entire system is currently configured as a single nPar, the system is expecting both cells to be present and will fail self-tests unless you delete the cell from the nPar configuration. You should change the nPar configuration (using the parmodify command or the nPar commands of the MP), perform a reconfiguration reboot (shutdown -R) and make sure the system starts up using just one cell board. Only after that you are free to physically remove the other cell board.

[bagek]

I did notice that the 2 mirrored root drives are on different cell paths. 1/0/0/3/0.6 and 0/0/0/3/0.6. I'll try moving them to the same cell. Thanks.  

[bagek]

we have 2 MP's and 2 mirrored root drives address is 1/0/0/3/0.6 for the top one and 0/0/0/3/0.6. Obviously they are are spread across both cells. we built this system as a backup to our production system and to replace a rp2470. our plan was to transfer the license from the rp2470 to the new rp7410. however HP is demanding an additional $18k for the new box because it has 4 cpus instead of the 2 in the rp2470. we don't need all the processing power of the 4 cpu box since it's just a back up. we would like to avoid rebuilding the box again with just 1 cell . is there a way to keep our current config and just turnoff 2 cpus? thanks. 

[Matti_Kurkela]

The easiest way to disable 2 CPUs would probably be to remove one cell from the current (only) nPar. As a bonus, you will have the option to use the cell for something else.

By changing the nPar configuration, you can essentially make the system into two separate servers within the single chassis. Based on what you've said so far, the only thing you'd need to do before that would be to move both your current boot disks to the top slots.

(Typical procedure in a nutshell: lvreduce -m 0 to remove each LV mirror from the disk to be moved, vgreduce the disk out of vg00, rmsf the disk, move it to a different physical location, ioscan, insf, vgextend, lvextend -m 1 for each LV, then lvlnboot & setboot to change boot paths to match the new config. No need to pvcreate or install the bootloader since the disk should already have it installed. No reboot required at this point - but you probably should take the time to confirm that both the primary & alternate boot paths are bootable.)

Then you could get 2 more disks, install them, and either clone your current setup with DRD to a new set of disks, or prepare an external DVD driver or an Ignite server for OS installation to the new partition that will be built out of Cell 0.

(Remember that the built-in removable media drive is connected to Cell 1, so it will be inaccessible to Cell 0 once the cells are split to separate nPars.)

Then use parmodify to change the nPar configuration and shutdown -R. Then you can start installing the OS to your new nPar... or use the MP commands to power down the other cell if you don't need it at this time (to reduce power consumption).

[bagek]

I main objective is to avoid paying an additional $18k to HP for the licensing for the 2 cpus on cell 0. If we follow your suggestions will this accomplish this? Thanks for all your help.

[Matti_Kurkela]

It depends on exactly which licenses you're talking about.

If it's about application licenses per CPU, splitting the system into nPars might be a valid way to avoid the licensing cost of the unneeded CPUs while still getting some use out of them in some other application.

But if you're thinking about OS licenses and/or hardware support, removing the cell might indeed be the only way to minimize the licensing costs.

[bagek]

we have decided to go with the 2 cell solution. thanks for your help. now we have another problem. we were given this box by another company and when we do uname -i it returns a "summ1dr" instead of a numeric string like our live system. any ideas why? thanks. 

[PrashanthShetty]

Hi,

It appears that the serial number and product numbers are not set in your case.

MP:CM>id   ==> Check if everything is in order

Set Product (original and current) and Serial numbers correctly using ID command.
Check the UUID currently configured is same as the one in the Product label/tag.
Reset the MP using XD command.
Reboot the system and check the uname -i command output along with machinfo to see the changes have taken effect.

Best Regards,

Prashanth

HP Employee...