I can restore the backup with the tar command but I lack the .conf file from the original Proxmox server it comes from. I restore the backup on a Debian 10 server.
Can I create the .conf file on the fly without copying it from the original Proxmox server ? If the answer is yes, how can I avoid pitfalls like the following one (occurs after I tried starting the container with a .conf file copied from Proxmox and adapted to the local Debian host) :
lxc-start 100 20210515073414.296 ERROR utils - utils.c:safe_mount:1179 - No such file or directory - Failed to mount "/dev/pts/5" onto "/dev/console"
lxc-start 100 20210515073414.296 ERROR conf - conf.c:lxc_setup_dev_console:1767 - Failed to mount "/dev/pts/5" on "/dev/console"
lxc-start 100 20210515073414.296 ERROR conf - conf.c:lxc_setup:3649 - Failed to setup console
lxc-start 100 20210515073414.296 ERROR start - start.c:do_start:1275 - Failed to setup container "100"
lxc-start 100 20210515073414.297 ERROR sync - sync.c:__sync_wait:62 - An error occurred in another process (expected sequence number 5)
lxc-start 100 20210515073414.297 ERROR start - start.c:__lxc_start:1951 - Failed to spawn container "100"
lxc-start 100 20210515073414.332 ERROR lxc_start - tools/lxc_start.c:main:330 - The container failed to start
If I try to start the container as privileged, I get the following log :
lxc-start 100 20210515080033.778 INFO lsm - lsm/lsm.c:lsm_init:50 - LSM security driver AppArmor
lxc-start 100 20210515080033.779 DEBUG terminal - terminal.c:lxc_terminal_peer_default:714 - Using terminal "/dev/tty" as proxy
lxc-start 100 20210515080033.779 DEBUG terminal - terminal.c:lxc_terminal_signal_init:192 - Created signal fd 9
lxc-start 100 20210515080033.779 DEBUG terminal - terminal.c:lxc_terminal_winsz:90 - Set window size to 175 columns and 51 rows
lxc-start 100 20210515080033.780 INFO start - start.c:lxc_init:904 - Container "100" is initialized
lxc-start 100 20210515080033.781 ERROR start - start.c:lxc_spawn:1693 - Operation not permitted - Failed to clone a new set of namespaces
lxc-start 100 20210515080033.781 DEBUG network - network.c:lxc_delete_network_unpriv:2362 - Cannot not guarantee safe deletion of network devices. Manual cleanup maybe needed
lxc-start 100 20210515080033.781 DEBUG network - network.c:lxc_delete_network:3178 - Failed to delete network devices
lxc-start 100 20210515080033.781 ERROR start - start.c:__lxc_start:1951 - Failed to spawn container "100"
lxc-start 100 20210515080033.782 ERROR lxc_start - tools/lxc_start.c:main:330 - The container failed to start
lxc-start 100 20210515080033.782 ERROR lxc_start - tools/lxc_start.c:main:336 - Additional information can be obtained by setting the --logfile and --logpriority options