How does it work if my ssd dies, where proxmox boot

If you only have 1 disk on your server (no RAID), you will have to

• buy a disk
• install in server
• reinstall Proxmox VE
• Install Proxmox BS
• have a regular backup on some other disk (e.g. USB HDD) to restore other VMs from

and the lvm for the containers is located on?

Are you talking about containers (lxc, docker) or the VM disks? You need a backup for VM disks anyway (Proxmox BS).

If you're talking about containers, I do not know how to backup those. I do use docker containers but they're all inside VMs. I like to seperate things via VMs, as a rogue container taking down it's VM (or having other negative effects on its host) is less of a headache than a rogue container taking down the whole hypervisor because it's running directly on the that.

For comparison, this is my disk setup for my server (my old PC):

# lsblk
nvme0n1     259:0    0 465.8G  0 disk
nvme1n1     259:1    0 465.8G  0 disk
sda           8:0    0   3.6T  0 disk
sdb           8:16   0   3.6T  0 disk
sdc           8:32   0   3.6T  0 disk

# zpool list
NAME        SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
data_raid  10.9T  2.40T  8.51T        -         -    26%    21%  1.00x    ONLINE  -
rpool       460G  7.31G   453G        -         -     8%     1%  1.00x    ONLINE  -

The 2 NVME-disks are used in a ZFS mirror (rpool in zpool list above) and store the Proxmox OS. The 3 SATA SSDs (see sd* in lsblk above) are housing all VM data in a ZFS RAID-Z1 called data_raid. With this hardware- and RAID-setup, one disk of each zpool could die right now and all I'd have to do is pay the currently horrendous hardware-prices and replace it. No data-loss or downtime until at least 2 disks of a single zpool die together.

All hardware dies at some point. Preperation is key.