Differences

This shows you the differences between two versions of the page.

--- zvm-linux_notes_on_running_linux_under_z_vm [2020/12/21 17:29]
prppedro [CPU's]
+++ — (current)
@@ Line 1: / Line 1: @@
-====== Some notes on running Linux under z/VM ======
-There's nothing much to say besides what the tutorial''[1]'' tells us. Nevertheless, there are quite a few notes I took just not to let me completely forget about them, later.
-===== CPU's =====
-I won't lie to you: it's insufferably slow. And for a good reason: you are virtualising twice, and the first level (Hercules) has zero paravirt. as s390x is a completely different architecture. But, maybe -- I said //maybe// -- you can suffer less, giving the VM more CPU's. So, here's how it's done:
-When creating the profile, you probably specified 4 max CPU's (''MACHINE ESA 4''). But that's it, when the machine is actually IPL'd, it goes up with only one.
-So, you take ''vmcp'', a neat little application which let you issue CP/CMS commands from inside Linux and do as follows [1]:
-<code>
-vmcp define cpu 02 type cp
-</code>
-There are other types of CPU other than CP[2], like:
-<code>
-CP
-    indicates the central processor.
-IFL
-    indicates the IBM® Integrated Facility for Linux.
-ZAAP
-    indicates the IBM zEnterprise® Application Assist Processor.
-ZIIP
-    indicates the IBM z Integrated Information Processor.
-ICF
-    indicates the Internal Coupling Facility.
-</code>
-But CP is the general kind. And I don't think we should bother much about IFL or others when running z/VM inside an emulated mainframe.
-Well, now your VM got a new CPU. It's offline, though:
-<code>
-vmcp q v cpus
-CPU 01  ID  FF0288F728288000 CP   CPUAFF ON
-CPU 02  ID  FF0288F728288000 STOPPED CP   CPUAFF ON
-[...]
-</code>
-Tell the guest to rescan for CPU's, by issuing ''chcpu -r''. If they don't come online (i.e. still ofline in ''lscpu -ae''), do this: ''chcpu -e 02''. And it'll probably come online.
-===== References =====
-  - {{ :zvm_install_guide.pdf |}}
-  - [[https://www.ibm.com/support/pages/dynamically-adding-or-removing-cpus-linux-zvm-guest|Dynamically adding or removing CPU's on Linux z/VM guests]]
-  - [[https://www.ibm.com/support/knowledgecenter/SSB27U_6.4.0/com.ibm.zvm.v640.hcpb7/defincpu.htm|DEFINE CPU]]

Tadeu's Wiki

User Tools

Site Tools

Differences

Page Tools