Proxmox VE

Proxmox Virtual Environment is a complete, open-source server management platform for enterprise virtualization. It tightly integrates the KVM hypervisor and Linux Containers (LXC), software-defined storage and networking functionality, on a single platform. With the integrated web-based user interface you can manage VMs and containers, high availability for clusters, or the integrated disaster recovery tools with ease.

See more: https://www.proxmox.com/en/proxmox-virtual-environment/overview

Download: https://www.proxmox.com/en/downloads/proxmox-virtual-environment

Post-install configuration:

Virtual machines

VM config location: /etc/pve/qemu-server/<ID>.conf

Create a VM via CLI

Proxmox VE qm command manual

See example: create-ubuntu-server-vm.sh

Kernel Samepage Merging (KSM)

KSM is a memory-saving de-duplication feature. See more: https://docs.kernel.org/admin-guide/mm/ksm.html

Check KSM statistics: watch cat /sys/kernel/mm/ksm/pages_sharing
Note: a page is 4096 bytes.

Proxmox VM Watchdogs

Proxmox VM Watchdogs

Force stop a VM

If Proxmox is stuck terminating a VM, as last resort, the kvm process can be forcefully terminated.

# Get the PID of the `kvm` process of the VM:
ps -auwx | grep <VMID>

# Force kill the `kvm` process:
kill -9 <KVM_PID>

Scheduled VM start/shutdown

To schedule starting and stopping a VM in Proxmox VE, create a file in /etc/cron.d e.g.:

sudo nano /etc/cron.d/vm-scheduler

Setup the scheduling, like:

# Start VM 100 at 8:00 AM
0 8 * * * root /usr/sbin/qm start <VMID>

# Stop VM 100 at 8:00 PM
0 20 * * * root /usr/sbin/qm stop <VMID>

LXC Containers

Connect to terminal: pct enter <CTID>

Create a container

proxmox_lxc_pct_provisioner.sh https://gist.github.com/tinoji/7e066d61a84d98374b08d2414d9524f2 pct create <id> /var/lib/vz/template/cache/centos-7-default_20170504_amd64.tar.xz ...

CLI examples (TODO cleanup):

pct create <id> /data/template/cache/debian-11-standard_11.3-1_amd64.tar.zst \
 -ostype <debian|centos|etc> \ \
 -hostname <hostname> \
 -cores <cores>  \
 -memory <memory(MB)> \
 -swap <swap(MB)> \
 -rootfs volume=main:<sizeInGB> \
 -net0 name=eth0,bridge=<bridge>,ip=dhcp,hwaddr=<macaddr format 00:00:00:00:00:00> \
 -ssh-public-keys ~/.ssh/authorized_keys

pct start <id>
pct create <id> /var/lib/vz/template/cache/centos-7-default_20170504_amd64.tar.xz \
    -arch amd64 \
    -ostype <centos|ubuntu|etc> \
    -hostname <hostname> \
    -cores <cores> \
    -memory <memory(MB)> \
    -swap <swap(MB)> \
    -storage local-lvm \
    -password \
    -net0 name=eth0,bridge=<bridge>,gw=<gateway>,ip=<cidr>,type=veth  &&\
pct start <id> &&\
sleep 10 &&\
pct resize <id> rootfs <storage(ex: +4G)> &&\
pct exec <id> -- bash -c "yum update -y &&\
    yum install -y openssh-server &&\
    systemctl start sshd &&\
    useradd -mU hogeuser &&\
    echo "password" | passwd --stdin hogeuser"

Issue: Cannot mount a SMB share

mount error(1): Operation not permitted
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs) and kernel log messages (dmesg)

You can’t mount any SMB/NFS share inside a unprivileged LXC. Thats only possible with the unsecure privileged LXCs after enabling the CIFS or NFS features under your LXC -> Options -> Features. If you want to use shares with a unprivileged LXC you need to mount the shares on your host and then use bind-mounts to bring the mounted share from your host into your LXC.