Using the excellent check_pve.rb script I have setup comprehensive monitoring for proxmox servers, both locally and remotely.

In case the script disappears, here are some useful bits

pveum useradd monitoring@pve -comment "Monitoring User"
pveum passwd monitoring@pve
pveum roleadd PVE_monitoring -privs "Datastore.Audit,Sys.Audit,Sys.Modify,VM.Audit"
pveum aclmod / -user monitoring@pve -role PVE_monitoring

Usage:

check_pve v0.2.5 [https://gitlab.com/6uellerBpanda/check_pve]

This plugin checks various parameters of Proxmox Virtual Environment via API(v2)

Mode:
  Cluster:
    cluster         Checks quorum of cluster
  Node:
    smart           Checks SMART health of disks
    updates         Checks for available updates
    subscription    Checks for valid subscription
    services        Checks if services are running
    storage         Checks storage usage in percentage
    cpu             Checks CPU usage in percentage
    memory          Checks Memory usage in gigabytes
    io_wait         Checks IO wait in percentage
    net_in          Checks inbound network usage in kilobytes
    net_out         Checks outbound network usage in kilobytes
    ksm             Checks KSM sharing usage in megabytes
  VM:
    vm_cpu          Checks CPU usage in percentage
    vm_disk_read    Checks how many kb last 60s was read (timeframe: hour)
    vm_disk_write   Checks how many kb last 60s was written (timeframe: hour)
    vm_net_in       Checks incoming kb from last 60s (timeframe: hour)
    vm_net_out      Checks outgoing kb from last 60s (timeframe: hour)

Usage: check_pve.rb [options]

Options:
    -s, -H, --address ADDRESS        PVE host address
    -k, --insecure                   No SSL verification
    -m, --mode MODE                  Mode to check
    -n, --node NODE                  PVE Node name
    -u, --username USERNAME          Username with auth realm e.g. monitoring@pve
    -p, --password PASSWORD          Password
    -w, --warning WARNING            Warning threshold
    -c, --critical CRITICAL          Critical threshold
        --name NAME                  Name for storage
    -i, --vmid VMID                  Vmid of lxc,qemu
    -t, --type TYPE                  VM type lxc or qemu
    -x, --exclude EXCLUDE            Exclude (regex)
        --timeframe TIMEFRAME        Timeframe for vm checks: hour,day,week,month or year
        --cf CONSOLIDATION_FUNCTION  RRD cf: average or max
    -v, --version                    Print version information
    -h, --help                       Show this help message