lxc-start throws Segmentation fault

Tommmii

Active Member
Jun 11, 2019
61
11
28
53
Hi all,

I force-stopped a non-responsive container, and now it won't start.
Have searched for something similar, but the search-results don't apply to this case.

Code:
root@pve:~# pveversion -v
proxmox-ve: 6.1-2 (running kernel: 5.3.13-1-pve)
pve-manager: 6.1-5 (running version: 6.1-5/9bf06119)
pve-kernel-5.3: 6.1-1
pve-kernel-helper: 6.1-1
pve-kernel-5.0: 6.0-11
pve-kernel-4.15: 5.4-6
pve-kernel-5.3.13-1-pve: 5.3.13-1
pve-kernel-5.3.10-1-pve: 5.3.10-1
pve-kernel-5.0.21-5-pve: 5.0.21-10
pve-kernel-5.0.21-4-pve: 5.0.21-9
pve-kernel-4.15.18-18-pve: 4.15.18-44
ceph-fuse: 12.2.11+dfsg1-2.1+b1
corosync: 3.0.2-pve4
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: 0.8.35+pve1
ksm-control-daemon: 1.3-1
libjs-extjs: 6.0.1-10
libknet1: 1.13-pve1
libpve-access-control: 6.0-5
libpve-apiclient-perl: 3.0-2
libpve-common-perl: 6.0-9
libpve-guest-common-perl: 3.0-3
libpve-http-server-perl: 3.0-3
libpve-storage-perl: 6.1-3
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve3
lxc-pve: 3.2.1-1
lxcfs: 3.0.3-pve60
novnc-pve: 1.1.0-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.1-1
pve-cluster: 6.1-2
pve-container: 3.0-15
pve-docs: 6.1-3
pve-edk2-firmware: 2.20191127-1
pve-firewall: 4.0-9
pve-firmware: 3.0-4
pve-ha-manager: 3.0-8
pve-i18n: 2.0-3
pve-qemu-kvm: 4.1.1-2
pve-xtermjs: 3.13.2-1
qemu-server: 6.1-4
smartmontools: 7.0-pve2
spiceterm: 3.1-1
vncterm: 1.6-1
zfsutils-linux: 0.8.2-pve2
root@pve:~#

Code:
root@pve:/etc/pve/lxc# pct config 104
arch: amd64
hostname: downloads
lock: mounted
memory: 1024
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.11.1,hwaddr=B2:0D:F9:92:9E:15,ip=192.168.11.8/24,type=veth
onboot: 0
ostype: debian
rootfs: zfs-containers:subvol-104-disk-0,size=8G
startup: order=100
swap: 512
root@pve:/etc/pve/lxc#

Code:
root@pve:~# lxc-start -n 104 -F -l DEBUG -o /tmp/lxc-104.log
lxc-start: 104: conf.c: run_buffer: 352 Script exited with status 2
lxc-start: 104: start.c: lxc_init: 897 Failed to run lxc.hook.pre-start for container "104"
lxc-start: 104: start.c: __lxc_start: 2032 Failed to initialize container "104"
Segmentation fault
root@pve:~#

Code:
root@pve:~# cat /tmp/lxc-104.log
lxc-start 104 20200103125938.277 INFO     lsm - lsm/lsm.c:lsm_init:50 - LSM security driver AppArmor
lxc-start 104 20200103125938.277 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "reject_force_umount  # comment this to allow umount -f;  not recommended"
lxc-start 104 20200103125938.277 INFO     seccomp - seccomp.c:do_resolve_add_rule:535 - Set seccomp rule to reject force umounts
lxc-start 104 20200103125938.277 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for reject_force_umount action 0(kill)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:do_resolve_add_rule:535 - Set seccomp rule to reject force umounts
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for reject_force_umount action 0(kill)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:do_resolve_add_rule:535 - Set seccomp rule to reject force umounts
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for reject_force_umount action 0(kill)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:do_resolve_add_rule:535 - Set seccomp rule to reject force umounts
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for reject_force_umount action 0(kill)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "[all]"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "kexec_load errno 1"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for kexec_load action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for kexec_load action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for kexec_load action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for kexec_load action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "open_by_handle_at errno 1"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for open_by_handle_at action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for open_by_handle_at action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for open_by_handle_at action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for open_by_handle_at action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "init_module errno 1"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for init_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for init_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for init_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for init_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "finit_module errno 1"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for finit_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for finit_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for finit_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for finit_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:789 - Processing "delete_module errno 1"
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:975 - Added native rule for arch 0 for delete_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:984 - Added compat rule for arch 1073741827 for delete_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:994 - Added compat rule for arch 1073741886 for delete_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1004 - Added native rule for arch -1073741762 for delete_module action 327681(errno)
lxc-start 104 20200103125938.278 INFO     seccomp - seccomp.c:parse_config_v2:1008 - Merging compat seccomp contexts into main context
lxc-start 104 20200103125938.278 INFO     conf - conf.c:run_script_argv:372 - Executing script "/usr/share/lxc/hooks/lxc-pve-prestart-hook" for container "104", config section "lxc"
lxc-start 104 20200103125939.402 DEBUG    conf - conf.c:run_buffer:340 - Script exec /usr/share/lxc/hooks/lxc-pve-prestart-hook 104 lxc pre-start produced output: unable to detect OS distribution

lxc-start 104 20200103125939.536 ERROR    conf - conf.c:run_buffer:352 - Script exited with status 2
lxc-start 104 20200103125939.537 ERROR    start - start.c:lxc_init:897 - Failed to run lxc.hook.pre-start for container "104"
lxc-start 104 20200103125939.538 ERROR    start - start.c:__lxc_start:2032 - Failed to initialize container "104"
root@pve:~#

Code:
root@pve:~# pct mount 104
mounted CT 104 in '/var/lib/lxc/104/rootfs'
root@pve:~# cat /var/lib/lxc/104/rootfs/etc/debian_version
9.11
root@pve:~#

Code:
root@pve:/etc/pve/lxc# cat /etc/pve/storage.cfg
dir: local
        path /var/lib/vz
        content iso,rootdir
        maxfiles 0
        shared 0

lvmthin: local-lvm
        thinpool data
        vgname pve
        content images,rootdir

zfspool: zfs-containers
        pool zfs-pool
        content rootdir
        sparse 0

zfspool: vm-disks
        pool zfs-pool/vm-disks
        content images
        sparse 1

dir: usb-backup
        path /mnt/usb-backup
        content backup
        maxfiles 3
        shared 0

dir: zfs-iso
        path /zfs-pool/iso
        content iso,vztmpl
        shared 0

root@pve:/etc/pve/lxc#

Any input greatly appreciated !!
 
hi,

firstly i'd like to thank you for providing all this information while asking the question :) it should be taken as an example

Script exec /usr/share/lxc/hooks/lxc-pve-prestart-hook 104 lxc pre-start produced output: unable to detect OS distribution

probably your zfs subvol isn't/wasn't mounted during the start. otherwise the log looks normal. is your zfs mounted?

lock: mounted

was this already there, or did the lock appear after you did pct mount?

since you can mount the container manually, i guess lxc is having some trouble mounting it.
 
i'd like to thank you for providing all this information
Thank you for thanking :p ... aka thankception.

is your zfs mounted?
Yes, it certainly was. Because I was able to cat /zfs-pool/subvol-104-disk-0/etc/debian_version. That would otherwise have thrown an error methinks?

did the lock appear after you did pct mount?
I can not be 100% certain, I think it appeared after. Because I did cp /etc/pve/lxc/104.conf /etc/pve/lxc/104.conf.bak at the beginning of all this, and the copy does not show anything about the lock...unsure if the lock would appear in the conf file anyway ?

So searching through the docs ( wiki Locks ), i tried pct unlock 104.
The damn thing started after this.

Now, I don't even ...

edited : etv ---> etc
 
glad your problem disappeared.

probably the lock was holding it from start... but pct would have reported that, and i think containers are still supposed to start even with a mount lock. (pct start ignores the mount lock)

if you reproduce this again, please let me know.
 
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