01-07-2014 10:24 PM
Hello expert Admins,
Is there any option to add/remove CPUs at OS level on BL870 Blade. I see an option at EFI shell.
cpuconfig [cpu #] [on/off] ............ We are looking for an option at OS itself without rebooing the server.
01-09-2014 01:49 AM
I don't think there is an exact equivalent to the cpuconfig tool available at EFI, but you can use the psrset command to assign CPU cores to a seperate PSET. If you then don't actually schedule any processes to run in that new PSET, the CPU is pretty much "off". There are probably some low level differences in how this works compared to cpuconfig especially for cores on a single socket and how they use cache, but I would imagine the upshot is broadly the same.
See man page for psrset for more details.
On Superdome and the older partitionable servers that support iCAP you could also use the icapmodify command to acheive this, but not on BL870.
01-09-2014 01:51 AM
I would also ask why you want to do this - if for licensing purposes, you have to be careful as it may not be recognised as a mechanism to restrict licensing by the ISV (e.g. Oracle don't recognise using PSETs on their own as a mechanism for managing per-core licensing, but they _do_ recognise it when PSETs are used in conjunction with Secure Resource Partitions - SRPs)