[SOLVED] AlmaLinux 10 LXC Start-Up Error

[Wolveraptor]

Hey there Proxmox Community!

Hoping to get get some assistance in diagnosing what the issue may be. It sounds like it may have something to do with this.

The below is the output of pct start 300 --debug.

INFO     confile - ../src/lxc/confile.c:set_config_idmaps:2295 - Read uid map: type u nsid 0 hostid 100000 range 65536
INFO     confile - ../src/lxc/confile.c:set_config_idmaps:2295 - Read uid map: type g nsid 0 hostid 100000 range 65536
INFO     lsm - ../src/lxc/lsm/lsm.c:lsm_init_static:38 - Initialized LSM security driver AppArmor
INFO     utils - ../src/lxc/utils.c:run_script_argv:587 - Executing script "/usr/share/lxc/hooks/lxc-pve-prestart-hook" for container "300", config section "lxc"
INFO     cgfsng - ../src/lxc/cgroups/cgfsng.c:unpriv_systemd_create_scope:1508 - Running privileged, not using a systemd unit
DEBUG    seccomp - ../src/lxc/seccomp.c:parse_config_v2:664 - Host native arch is [3221225534]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "reject_force_umount  # comment this to allow umount -f;  not recommended"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:532 - Set seccomp rule to reject force umounts
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:532 - Set seccomp rule to reject force umounts
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:532 - Set seccomp rule to reject force umounts
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "[all]"
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "kexec_load errno 1"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[246:kexec_load] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[246:kexec_load] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[246:kexec_load] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "open_by_handle_at errno 1"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[304:open_by_handle_at] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[304:open_by_handle_at] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[304:open_by_handle_at] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "init_module errno 1"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[175:init_module] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[175:init_module] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[175:init_module] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "finit_module errno 1"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[313:finit_module] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[313:finit_module] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[313:finit_module] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "delete_module errno 1"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[176:delete_module] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[176:delete_module] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[176:delete_module] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "ioctl errno 1 [1,0x9400,SCMP_CMP_MASKED_EQ,0xff00]"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:555 - arg_cmp[0]: SCMP_CMP(1, 7, 65280, 37888)
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[16:ioctl] action[327681:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:555 - arg_cmp[0]: SCMP_CMP(1, 7, 65280, 37888)
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[16:ioctl] action[327681:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:555 - arg_cmp[0]: SCMP_CMP(1, 7, 65280, 37888)
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[16:ioctl] action[327681:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "keyctl errno 38"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[250:keyctl] action[327718:errno] arch[0]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[250:keyctl] action[327718:errno] arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[250:keyctl] action[327718:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:815 - Processing "socket errno 97 [0,38,SCMP_CMP_EQ]"
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:555 - arg_cmp[0]: SCMP_CMP(0, 4, 0, 38)
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding native rule for syscall[41:socket] action[327777:errno] arch[0]
DEBUG    seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:549 - The syscall[41:socket] is not supported on compat arch[1073741827]
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:555 - arg_cmp[0]: SCMP_CMP(0, 4, 0, 38)
INFO     seccomp - ../src/lxc/seccomp.c:do_resolve_add_rule:572 - Adding compat rule for syscall[41:socket] action[327777:errno] arch[1073741886]
INFO     seccomp - ../src/lxc/seccomp.c:parse_config_v2:1036 - Merging compat seccomp contexts into main context
INFO     start - ../src/lxc/start.c:lxc_init:882 - Container "300" is initialized
INFO     cgfsng - ../src/lxc/cgroups/cgfsng.c:cgfsng_monitor_create:1679 - The monitor process uses "lxc.monitor/300" as cgroup
DEBUG    storage - ../src/lxc/storage/storage.c:storage_query:231 - Detected rootfs type "dir"
DEBUG    storage - ../src/lxc/storage/storage.c:storage_query:231 - Detected rootfs type "dir"
INFO     cgfsng - ../src/lxc/cgroups/cgfsng.c:cgfsng_payload_create:1787 - The container process uses "lxc/300/ns" as inner and "lxc/300" as limit cgroup
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWUSER
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWNS
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWPID
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWUTS
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWIPC
INFO     start - ../src/lxc/start.c:lxc_spawn:1781 - Cloned CLONE_NEWCGROUP
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved user namespace via fd 17 and stashed path as user:/proc/103435/fd/17
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved mnt namespace via fd 18 and stashed path as mnt:/proc/103435/fd/18
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved pid namespace via fd 19 and stashed path as pid:/proc/103435/fd/19
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved uts namespace via fd 20 and stashed path as uts:/proc/103435/fd/20
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved ipc namespace via fd 21 and stashed path as ipc:/proc/103435/fd/21
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved cgroup namespace via fd 22 and stashed path as cgroup:/proc/103435/fd/22
DEBUG    idmap_utils - ../src/lxc/idmap_utils.c:idmaptool_on_path_and_privileged:93 - The binary "/usr/bin/newuidmap" does have the setuid bit set
DEBUG    idmap_utils - ../src/lxc/idmap_utils.c:idmaptool_on_path_and_privileged:93 - The binary "/usr/bin/newgidmap" does have the setuid bit set
DEBUG    idmap_utils - ../src/lxc/idmap_utils.c:lxc_map_ids:178 - Functional newuidmap and newgidmap binary found
INFO     cgfsng - ../src/lxc/cgroups/cgfsng.c:cgfsng_setup_limits:3538 - Limits for the unified cgroup hierarchy have been setup
DEBUG    idmap_utils - ../src/lxc/idmap_utils.c:idmaptool_on_path_and_privileged:93 - The binary "/usr/bin/newuidmap" does have the setuid bit set
DEBUG    idmap_utils - ../src/lxc/idmap_utils.c:idmaptool_on_path_and_privileged:93 - The binary "/usr/bin/newgidmap" does have the setuid bit set
INFO     idmap_utils - ../src/lxc/idmap_utils.c:lxc_map_ids:176 - Caller maps host root. Writing mapping directly
NOTICE   utils - ../src/lxc/utils.c:lxc_drop_groups:1481 - Dropped supplimentary groups
INFO     start - ../src/lxc/start.c:do_start:1105 - Unshared CLONE_NEWNET
NOTICE   utils - ../src/lxc/utils.c:lxc_drop_groups:1481 - Dropped supplimentary groups
NOTICE   utils - ../src/lxc/utils.c:lxc_switch_uid_gid:1457 - Switched to gid 0
NOTICE   utils - ../src/lxc/utils.c:lxc_switch_uid_gid:1466 - Switched to uid 0
DEBUG    start - ../src/lxc/start.c:lxc_try_preserve_namespace:140 - Preserved net namespace via fd 5 and stashed path as net:/proc/103435/fd/5
INFO     utils - ../src/lxc/utils.c:run_script_argv:587 - Executing script "/usr/share/lxc/lxcnetaddbr" for container "300", config section "net"
DEBUG    network - ../src/lxc/network.c:netdev_configure_server_veth:879 - Instantiated veth tunnel "veth300i0 <--> vethYOc5C5"
DEBUG    conf - ../src/lxc/conf.c:lxc_mount_rootfs:1223 - Mounted rootfs "/var/lib/lxc/300/rootfs" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs" with options "(null)"
INFO     conf - ../src/lxc/conf.c:setup_utsname:671 - Set hostname to "sns-almalinux10lxc"
DEBUG    network - ../src/lxc/network.c:setup_hw_addr:3866 - Mac address "BC:24:11:1B:7C:CF" on "eth0" has been setup
DEBUG    network - ../src/lxc/network.c:lxc_network_setup_in_child_namespaces_common:4007 - Network device "eth0" has been setup
INFO     network - ../src/lxc/network.c:lxc_setup_network_in_child_namespaces:4064 - Finished setting up network devices with caller assigned names
INFO     conf - ../src/lxc/conf.c:mount_autodev:1006 - Preparing "/dev"
INFO     conf - ../src/lxc/conf.c:mount_autodev:1067 - Prepared "/dev"
DEBUG    conf - ../src/lxc/conf.c:lxc_mount_auto_mounts:531 - Invalid argument - Tried to ensure procfs is unmounted
DEBUG    conf - ../src/lxc/conf.c:lxc_mount_auto_mounts:554 - Invalid argument - Tried to ensure sysfs is unmounted
DEBUG    conf - ../src/lxc/conf.c:mount_entry:2208 - Remounting "/sys/fs/fuse/connections" on "/usr/lib/x86_64-linux-gnu/lxc/rootfs/sys/fs/fuse/connections" to respect bind or remount options
DEBUG    conf - ../src/lxc/conf.c:mount_entry:2227 - Flags for "/sys/fs/fuse/connections" were 4110, required extra flags are 14
DEBUG    conf - ../src/lxc/conf.c:mount_entry:2271 - Mounted "/sys/fs/fuse/connections" on "/usr/lib/x86_64-linux-gnu/lxc/rootfs/sys/fs/fuse/connections" with filesystem type "none"
DEBUG    conf - ../src/lxc/conf.c:mount_entry:2271 - Mounted "proc" on "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/.lxc/proc" with filesystem type "proc"
DEBUG    conf - ../src/lxc/conf.c:mount_entry:2271 - Mounted "sys" on "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/.lxc/sys" with filesystem type "sysfs"
DEBUG    cgfsng - ../src/lxc/cgroups/cgfsng.c:__cgroupfs_mount:2197 - Mounted cgroup filesystem cgroup2 onto 19((null))
INFO     utils - ../src/lxc/utils.c:run_script_argv:587 - Executing script "/usr/share/lxcfs/lxc.mount.hook" for container "300", config section "lxc"
INFO     utils - ../src/lxc/utils.c:run_script_argv:587 - Executing script "/usr/share/lxc/hooks/lxc-pve-autodev-hook" for container "300", config section "lxc"
INFO     conf - ../src/lxc/conf.c:lxc_fill_autodev:1104 - Populating "/dev"
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/full) to 18(full)
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/null) to 18(null)
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/random) to 18(random)
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/tty) to 18(tty)
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/urandom) to 18(urandom)
DEBUG    conf - ../src/lxc/conf.c:lxc_fill_autodev:1188 - Bind mounted host device 16(dev/zero) to 18(zero)
INFO     conf - ../src/lxc/conf.c:lxc_fill_autodev:1192 - Populated "/dev"
INFO     conf - ../src/lxc/conf.c:lxc_transient_proc:3302 - Caller's PID is 1; /proc/self points to 1
DEBUG    conf - ../src/lxc/conf.c:lxc_setup_devpts_child:1537 - Attached detached devpts mount 20 to 18/pts
DEBUG    conf - ../src/lxc/conf.c:lxc_setup_devpts_child:1623 - Created "/dev/ptmx" file as bind mount target
DEBUG    conf - ../src/lxc/conf.c:lxc_setup_devpts_child:1630 - Bind mounted "/dev/pts/ptmx" to "/dev/ptmx"
DEBUG    conf - ../src/lxc/conf.c:lxc_allocate_ttys:900 - Created tty with ptx fd 22 and pty fd 23 and index 1
DEBUG    conf - ../src/lxc/conf.c:lxc_allocate_ttys:900 - Created tty with ptx fd 24 and pty fd 25 and index 2
INFO     conf - ../src/lxc/conf.c:lxc_allocate_ttys:905 - Finished creating 2 tty devices
DEBUG    conf - ../src/lxc/conf.c:lxc_setup_ttys:861 - Bind mounted "pts/1" onto "tty1"
DEBUG    conf - ../src/lxc/conf.c:lxc_setup_ttys:861 - Bind mounted "pts/2" onto "tty2"
INFO     conf - ../src/lxc/conf.c:lxc_setup_ttys:868 - Finished setting up 2 /dev/tty<N> device(s)
INFO     conf - ../src/lxc/conf.c:setup_personality:1703 - Set personality to "0lx0"
DEBUG    conf - ../src/lxc/conf.c:capabilities_deny:2999 - Capabilities have been setup
NOTICE   conf - ../src/lxc/conf.c:lxc_setup:4009 - The container "300" is set up
INFO     apparmor - ../src/lxc/lsm/apparmor.c:apparmor_process_label_set_at:1188 - Set AppArmor label to "lxc-300_</var/lib/lxc>//&:lxc-300_<-var-lib-lxc>:"
INFO     apparmor - ../src/lxc/lsm/apparmor.c:apparmor_process_label_set:1233 - Changed AppArmor profile to lxc-300_</var/lib/lxc>//&:lxc-300_<-var-lib-lxc>:
DEBUG    terminal - ../src/lxc/terminal.c:lxc_terminal_peer_default:704 - No such device - The process does not have a controlling terminal
NOTICE   start - ../src/lxc/start.c:start:2213 - Exec'ing "/sbin/init"
NOTICE   start - ../src/lxc/start.c:post_start:2224 - Started "/sbin/init" with pid "103476"
NOTICE   start - ../src/lxc/start.c:signal_handler:447 - Received 17 from pid 103472 instead of container init 103476
INFO     error - ../src/lxc/error.c:lxc_error_set_and_log:31 - Child <103476> ended on error (127)
lxc-info: 300: ../src/lxc/af_unix.c: lxc_abstract_unix_recv_fds_iov: 218 Connection reset by peer - Failed to receive response
lxc-info: 300: ../src/lxc/commands.c: lxc_cmd_rsp_recv_fds: 128 Failed to receive file descriptors for command "get_init_pid"
unable to get PID for CT 300 (not running?)

Below is the configuration of the Linux Container

arch: amd64
features: nesting=1
hostname: test-almalinux10lxc
memory: 4096
nameserver: <REDACTED>
net0: name=eth0,bridge=vmbr1,firewall=1,hwaddr=BC:24:11:C8:8F:78,ip=dhcp,ip6=auto,tag=10,type=veth
ostype: centos
rootfs: local-raid5:vm-300-disk-0,mountoptions=discard,size=5G
searchdomain: <REDACTED>
swap: 1024
unprivileged: 1

Second post required that contains additional information as this post exceeds character limit.

 

[Wolveraptor]

I also tried making a privileged LXC but it is the same error. I do recall that RHEL 10 as a VM also does not work and the LXC behavior seems similar to this post about RHEL, AlmaLinux, and Rocky Linux 10 in this post. Unfortunately, since I desire to run AlmaLinux in an LXC I am not aware of a way to change/emulate a different CPU. This post may also be related and this reply in particular?

Interestingly, the almalinux-9-default_20240911_amd64.tar.xz LXC image does NOT fail to start, it works.

I have also tested the Proxmox downloadable almalinux-10-default_20250930_amd64.tar.xz LXC image in addition to those available on the https://images.linuxcontainers.org website but those do not work either.



I am not sure where else/what else to troubleshoot.

Information about my host:

CPU(s): 40 x Intel(R) Xeon(R) CPU E5-2670 v2 @ 2.50GHz (2 Sockets)
Kernel Version: Linux 7.0.2-2-pve (2026-05-08T06:08Z)
Boot Mode: EFI
Manager Version: pve-manager/9.1.9/ee7bad0a3d1546c9

List of packages and versions installed on my host:

proxmox-ve: 9.1.0 (running kernel: 7.0.2-2-pve)
pve-manager: 9.1.9 (running version: 9.1.9/ee7bad0a3d1546c9)
proxmox-kernel-helper: 9.0.4
proxmox-kernel-7.0: 7.0.2-2
proxmox-kernel-7.0.2-2-pve-signed: 7.0.2-2
proxmox-kernel-7.0.0-3-pve-signed: 7.0.0-3
proxmox-kernel-6.17.13-7-pve-signed: 6.17.13-7
proxmox-kernel-6.17: 6.17.13-7
proxmox-kernel-6.17.13-6-pve-signed: 6.17.13-6
proxmox-kernel-6.17.13-3-pve-signed: 6.17.13-3
proxmox-kernel-6.8.12-13-pve-signed: 6.8.12-13
proxmox-kernel-6.8: 6.8.12-13
proxmox-kernel-6.8.4-2-pve-signed: 6.8.4-2
ceph-fuse: 19.2.3-pve1
corosync: 3.1.10-pve2
criu: 4.1.1-1
frr-pythontools: 10.4.1-1+pve1
ifupdown2: 3.3.0-1+pmx12
intel-microcode: 3.20251111.1~deb13u1
ksm-control-daemon: 1.5-1
libjs-extjs: 7.0.0-5
libproxmox-acme-perl: 1.7.1
libproxmox-backup-qemu0: 2.0.2
libproxmox-rs-perl: 0.4.1
libpve-access-control: 9.0.7
libpve-apiclient-perl: 3.4.2
libpve-cluster-api-perl: 9.1.2
libpve-cluster-perl: 9.1.2
libpve-common-perl: 9.1.11
libpve-guest-common-perl: 6.0.2
libpve-http-server-perl: 6.0.5
libpve-network-perl: 1.3.0
libpve-notify-perl: 9.1.2
libpve-rs-perl: 0.13.0
libpve-storage-perl: 9.1.2
libspice-server1: 0.15.2-1+b1
lvm2: 2.03.31-2+pmx1
lxc-pve: 6.0.5-4
lxcfs: 6.0.4-pve1
novnc-pve: 1.6.0-4
proxmox-backup-client: 4.2.0-1
proxmox-backup-file-restore: 4.2.0-1
proxmox-backup-restore-image: 1.0.0
proxmox-firewall: 1.2.2
proxmox-kernel-helper: 9.0.4
proxmox-mail-forward: 1.0.3
proxmox-mini-journalreader: 1.6
proxmox-offline-mirror-helper: 0.7.3
proxmox-widget-toolkit: 5.1.9
pve-cluster: 9.1.2
pve-container: 6.1.5
pve-docs: 9.1.2
pve-edk2-firmware: 4.2025.05-2
pve-esxi-import-tools: 1.0.1
pve-firewall: 6.0.4
pve-firmware: 3.18-3
pve-ha-manager: 5.2.0
pve-i18n: 3.7.1
pve-qemu-kvm: 10.1.2-7
pve-xtermjs: 5.5.0-3
qemu-server: 9.1.9
smartmontools: 7.4-pve1
spiceterm: 3.4.2
swtpm: 0.8.0+pve3
vncterm: 1.9.2
zfsutils-linux: 2.4.1-pve1

I may have answered my own question, AlmaLinux 10.1, since it follows RHEL, is dropping support for the V2 architecture which is what my host cpu is. AlmaLinux article here so, I'd have to build a V2 LXC image that supports my CPU. Basically, I think I'm hitting the point where my CPU is too old and as operating systems progress, they're dropping support for older hardware which makes sense. Since this is an LXC, I cannot emulate a different CPU with a different instruction set so unless V2 LXC images get built, which would explain why AlmaLinux 8 and 9 LXCs work (because they support V2), running Alma Linux 10 as an LXC will not work with my older hardware.

I think that is indeed my problem, my CPU is too old and does not support the x86-64-v3 microarchitecture.

Output of /lib64/ld-linux-x86-64.so.2 --help:

Subdirectories of glibc-hwcaps directories, in priority order:
  x86-64-v4
  x86-64-v3
  x86-64-v2 (supported, searched)

Is my above deduction correct?

 

[fschauer]

Is my above deduction correct?

Yes. Starting with RHEL 10 / AlmaLinux 10, at least the x86-64-v3 microarchitecture is required. Your Intel Xeon E5-2670 only satisfies x86-64-v2 requirements.

Verifying in a VM with a virtual x86-64-v2 processor running Proxmox VE:

# pct mount 101
mounted CT 101 in '/var/lib/lxc/101/rootfs'
# chroot /var/lib/lxc/101/rootfs
Fatal glibc error: CPU does not support x86-64-v3

Looking at your debug logs, the container startup fails with:

INFO error - ../src/lxc/error.c:lxc_error_set_and_log:31 - Child <103476> ended on error (127)

lxc-info: 300: ../src/lxc/commands.c: lxc_cmd_rsp_recv_fds: 128 Failed to receive file descriptors for command "get_init_pid"

This happens because the container's init process and by extension LXC exit immediately before Proxmox VE has a chance to grab its PID. But I agree that this error could probably be conveyed a little better to the user.

 

[Wolveraptor]

Yes. Starting with RHEL 10 / AlmaLinux 10, at least the x86-64-v3 microarchitecture is required. Your Intel Xeon E5-2670 only satisfies x86-64-v2 requirements.

Verifying in a VM with a virtual x86-64-v2 processor running Proxmox VE:

# pct mount 101
mounted CT 101 in '/var/lib/lxc/101/rootfs'
# chroot /var/lib/lxc/101/rootfs
Fatal glibc error: CPU does not support x86-64-v3

Looking at your debug logs, the container startup fails with:


This happens because the container's init process and by extension LXC exit immediately before Proxmox VE has a chance to grab its PID. But I agree that this error could probably be conveyed a little better to the user.

Hey @fschauer , this makes sense and I appreciate you taking the time to confirm and explain the behavior to me; thank you!

I will be marking this post as [SOLVED].