There is a lot of good descriptions how to set it up, however – as Pi-diet does not use classic sshd but `dropbear` `pvecm qdevice setup` does not work:

# pvecm qdevice setup 192.168.1.202 -f
/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed

/bin/ssh-copy-id: WARNING: All keys were skipped because they already exist on the remote system.
		(if you think this is a mistake, you may want to use -f option)


INFO: initializing qnetd server
Certificate database (/etc/corosync/qnetd/nssdb) already exists. Delete it to initialize new db

INFO: copying CA cert and initializing on all nodes
bash: line 1: /usr/lib/sftp-server: No such file or directory
scp: Connection closed
command 'scp -o 'BatchMode=yes' 'root@[192.168.1.202]:/etc/corosync/qnetd/nssdb/qnetd-cacert.crt' /etc/pve/qnetd-cacert.crt' failed: exit code 255

Solution

Use a lightweight sftp server and fool pve that it is `/usr/lib/sftp-server`

# apt install gesftpserver
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  gesftpserver
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 28.5 kB of archives.
After this operation, 75.8 kB of additional disk space will be used.
Get:1 http://raspbian.raspberrypi.com/raspbian bullseye/main armhf gesftpserver armhf 1~ds-3 [28.5 kB]
Fetched 28.5 kB in 2s (13.1 kB/s)
debconf: delaying package configuration, since apt-utils is not installed
Selecting previously unselected package gesftpserver.
(Reading database ... 24944 files and directories currently installed.)
Preparing to unpack .../gesftpserver_1~ds-3_armhf.deb ...
Unpacking gesftpserver (1~ds-3) ...
Setting up gesftpserver (1~ds-3) ...

# ln -s /usr/libexec/gesftpserver /usr/lib/sftp-server

References

• https://florianmuller.com/setup-a-proxmox-two-node-high-availability-cluster-with-a-raspberrypi-as-a-third-quorum-vote-device-qdevice