Memory hot plug: increase the number of slots from '32' to '256' (Documentation)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Ubuntu Server Guide |
Won't Fix
|
Undecided
|
Unassigned |
Bug Description
IBM would like to have the following documented wherever appropriate:
---Problem Description---
In Ubuntu 17.04, when trying to increase the number of memory slots from 32 to 256, only 63 slots were available even though 256 slots was specified in the guest xml.
Machine Type = POWER8
Even though 256 slots are supported in QEMU 2.8, distributed with Ubuntu 17.04, there is an implicit limit coming from the vhost backend, limiting the number of max memory slots that are supported.
The work around is to increase the vhost mem slots by reloading the vhost module in the guest:
[root@localhost ~]# modprobe -r vhost
[root@localhost ~]# modprobe vhost max_mem_regions=512
[root@localhost ~]# cat /sys/module/
512
tags: | added: architecture-ppc64le bugnameltc-151531 severity-medium targetmilestone-inin1704 |
Changed in ubuntu: | |
assignee: | nobody → Taco Screen team (taco-screen-team) |
affects: | ubuntu → ubuntu-docs (Ubuntu) |
Hi!
You filed this bug report against the ubuntu-docs package, which is a basic user documentation for the Ubuntu desktop. To be honest, what you talk about is far above my head, but I doubt that the topic is suitable for ubuntu-docs.
Can you please provide some further information, so we can figure out which kind of docs (if any) might be affected.