KVM VM (64GB) won't start with memory hotplug enabled

Jul 1, 2014
22
0
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Hello,

This had been asked several times however after extensive search there is still no real answer that would make sense or a formula that I was able to follow to assign memory - sometime it work and sometimes doesn't (guessing!)

up to 48GB works fine after adding this workaround "options vhost max_mem_regions=509" in /etc/modprobe.d/vhost.conf however other configurations shows errors

Below are examples of the errors with 64GB, 96GB, 128GB, 224GB
64GB: TASK ERROR: memory size (65536) must be aligned to 2048 for hotplugging
96GB: TASK ERROR: memory size (98304) must be aligned to 2048 for hotplugging
128GB: TASK ERROR: memory size (131072) must be aligned to 4096 for hotplugging
132GB: TASK ERROR: memory size (135168) must be aligned to 4096 for hotplugging

Tested with and without Baloon settings...

I also tried @fabian suggestion for 64GB and adding 1G extra works however I can't have a consistent way to apply other variations - for example, 58GB or 50GB, 66Gb etc..

Below are some details and thanks in advance

Reference threads :

https://forum.proxmox.com/threads/problem-with-hotplug-and-64gb-ram.73621/
https://forum.proxmox.com/threads/vm-windows-cannot-start-with-ram-more-48gb.76617/


Bugs reported:
https://bugzilla.proxmox.com/show_bug.cgi?id=3446
https://bugzilla.proxmox.com/show_bug.cgi?id=1426


Server details:

1622387447052.png
1622388578909.png

pveversion -v
proxmox-ve: 6.4-1 (running kernel: 5.4.114-1-pve)
pve-manager: 6.4-6 (running version: 6.4-6/be2fa32c)
pve-kernel-5.4: 6.4-2
pve-kernel-helper: 6.4-2
pve-kernel-5.4.114-1-pve: 5.4.114-1
pve-kernel-5.4.106-1-pve: 5.4.106-1
ceph: 15.2.11-pve1
ceph-fuse: 15.2.11-pve1
corosync: 3.1.2-pve1
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: residual config
ifupdown2: 3.0.0-1+pve3
ksmtuned: 4.20150325+b1
libjs-extjs: 6.0.1-10
libknet1: 1.20-pve1
libproxmox-acme-perl: 1.1.0
libproxmox-backup-qemu0: 1.0.3-1
libpve-access-control: 6.4-1
libpve-apiclient-perl: 3.1-3
libpve-common-perl: 6.4-3
libpve-guest-common-perl: 3.1-5
libpve-http-server-perl: 3.2-2
libpve-network-perl: 0.6.0
libpve-storage-perl: 6.4-1
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve4
lxc-pve: 4.0.6-2
lxcfs: 4.0.6-pve1
novnc-pve: 1.1.0-1
proxmox-backup-client: 1.1.6-2
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.5-5
pve-cluster: 6.4-1
pve-container: 3.3-5
pve-docs: 6.4-2
pve-edk2-firmware: 2.20200531-1
pve-firewall: 4.1-3
pve-firmware: 3.2-3
pve-ha-manager: 3.1-1
pve-i18n: 2.3-1
pve-qemu-kvm: 5.2.0-6
pve-xtermjs: 4.7.0-3
qemu-server: 6.4-2
smartmontools: 7.2-pve2
spiceterm: 3.1-1
vncterm: 1.6-2
zfsutils-linux: 2.0.4-pve1
 

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