Bug 49843 – Add settings to allow UCS dealing with hot-added memory and cpus by default

Bug 49843 - Add settings to allow UCS dealing with hot-added memory and cpus by default


Summary:	Add settings to allow UCS dealing with hot-added memory and cpus by default

Status:	NEW

Product:	UCS
Classification:	Unclassified
Component:	System setup
Version:	UCS 4.4
Hardware:	Other Linux

Importance:	P5 normal (vote)
Target Milestone:	UCS 5.0-0-errata
Assigned To:	UCS maintainers
QA Contact:	UCS maintainers

URL:	https://help.univention.com/t/how-to-...
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2019-07-12 16:04 CEST by Christian Völker
Modified:	2021-04-28 10:16 CEST (History)
CC List:	2 users (show)

See Also:
What kind of report is it?:	Feature Request
What type of bug is this?:	4: Minor Usability: Impairs usability in secondary scenarios
Who will be affected by this bug?:	2: Will only affect a few installed domains
How will those affected feel about the bug?:	2: A Pain – users won’t like this once they notice it
User Pain:	0.091
Enterprise Customer affected?:	Yes
School Customer affected?:
ISV affected?:
Waiting Support:
Flags outvoted (downgraded) after PO Review:
Ticket number:	2019070921001128, 2020061121000025
Bug group (optional):
Max CVSS v3 score:

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Description Christian Völker

2019-07-12 16:04:59 CEST

In default settings UCS does not allow hot-adding CPUs or memory (RAM) even when allowed and done by the hypervisor (ESXi, Proxmoxx).

You can configure UCS to activate added resource automatically.
Create a file named “94-hotplug-cpu-mem.rules” in the folder /etc/udev/rules.d with the following content:

ACTION=="add", SUBSYSTEM=="cpu", ATTR{online}=="0", ATTR{online}="1"

ACTION=="add", SUBSYSTEM=="memory", ATTR{state}=="offline", ATTR{state}="online"

Then reboot your VM. After reboot all hot-added cpus or memory will automatically detected and activated.

We should possibly include this file in UCS by default so no configuration has to be done by customer to enable this feature.

Many customers prefer to *not* reboot their server just for adding CPUs or memory.

Especially this would be helpful if a server is at high load and needs more memory or cpus.