====== On existing Debian ======

Install Proxmox on ready Debian system. 
Benefits:
  * unusual disk setup (i.e. not using ZFS for raid, only generic MD or LVM raid)
  * for lazy people: running system with remote access only


===== Setup repositories =====

[[https://pve.proxmox.com/pve-docs/pve-admin-guide.html#sysadmin_package_repositories|Package Repositories]]
Detailed step-by-step instuciton [[https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_Buster|wiki]]

It is very important (to SSL key generation), that hostname is resolved do IP address of device:
<code bash>
hostname --ip-address
192.168.15.77 # should return your IP address here
</code>

<code bash>
echo 'deb http://download.proxmox.com/debian/pve buster pve-no-subscription' > /etc/apt/sources.list.d/pve-no-sub.list</code>
wget http://download.proxmox.com/debian/proxmox-ve-release-6.x.gpg -O /etc/apt/trusted.gpg.d/proxmox-ve-release-6.x.gpg
apt-get update
apt-get remove network-manager
apt-get install ifupdown2 open-iscsi ksmtuned
apt-get remove ntp
systemctl enable --now systemd-timesyncd
apt-get install proxmox-ve
apt-get install pve-headers
</code>

To avoid GFX issues disable ''modeset'':
<file | /etc/default/grub>
GRUB_CMDLINE_LINUX_DEFAULT="mitigations=off panic=30 nomodeset"
</file>

Reboot system.
System will boot with default Debian kernel, because Buster Backports kernel is newer than Proxmox one.
With dfault Debian kernel there is no ZFS support, and also Docker engine cannot work because of some apparmor issues.

To try to boor PVE kernel once:
<file | /etc/default/grub>
GRUB_DEFAULT=saved
# Comment or disable:
# GRUB_SAVEDEFAULT=true
</file>

<code bash>
update-grub
# get menu ids:
egrep -i "menuentry '|submenu '" /boot/grub/grub.cfg
# Set grub env using chosen ids. For submenu use '>'
grub-set-default 'gnulinux-simple-21b9a8a1-48e8-4c4d-8420-6c97870f2702'
grub-reboot 'gnulinux-advanced-21b9a8a1-48e8-4c4d-8420-6c97870f2702>gnulinux-5.3.18-3-pve-advanced-21b9a8a1-48e8-4c4d-8420-6c97870f2702'
</code>

If everything works well, remove Debian kernel.
<code bash>
apt remove linux-image-amd64 'linux-image-4.19*' 'linux-image-5.4*'
update-grub
grub-set-default 0
</code>




===== issues =====

==== pveproxy: failed to load local private key  ====

Proxmox was installed with incorrect /etc/hosts configuration. After fixing it still shows errors in journal:
<code>
pveproxy[26742]: /etc/pve/local/pve-ssl.key: failed to load local private key (key_file or key) at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1727.
pveproxy[26743]: /etc/pve/local/pve-ssl.key: failed to load local private key (key_file or key) at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1727.
</code>

<code bash>
journalctl -u pve-cluster

systemd[1]: Stopped The Proxmox VE cluster filesystem.
systemd[1]: Starting The Proxmox VE cluster filesystem...
pmxcfs[2398]: [main] crit: Unable to get local IP address
pmxcfs[2398]: [main] crit: Unable to get local IP address
systemd[1]: pve-cluster.service: Control process exited, code=exited, status=255/EXCEPTION
systemd[1]: pve-cluster.service: Failed with result 'exit-code'.
systemd[1]: Failed to start The Proxmox VE cluster filesystem.
</code>

Reason cluster FS on ''/etc/pve'' was not started, symlinks to nodes points to nowhere:
<code>
/etc/pve# tree
.
├── local -> nodes/host281
├── lxc -> nodes/host281/lxc
├── openvz -> nodes/host281/openvz
└── qemu-server -> nodes/host281/qemu-server

</code>

Reboot device

==== local-zfs  ====

Missing ''local-zfs''.