Can't start VM on 4.4

I’ve been trying to test VM support but I can’t seem to get things working.

This is on a bare metal Intel server.

root@dream:~# lxd --version
4.4
root@dream:~# lxc --version
4.4

root@dream:~# lsmod | grep kvm
kvm_intel             253952  0
kvm                   655360  1 kvm_intel

root@dream:~# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.5 LTS"

root@dream:~# lxc start vm-test
Error: Failed to run: /snap/lxd/current/bin/lxd forklimits limit=memlock:unlimited:unlimited -- /snap/lxd/16889/bin/qemu-system-x86_64 -S -name vm-test -uuid ada89440-ec5e-403c-85c8-e7a4658c8563 -daemonize -cpu host -nographic -serial chardev:console -nodefaults -no-reboot -no-user-config -sandbox on,obsolete=deny,elevateprivileges=allow,spawn=deny,resourcecontrol=deny -readconfig /var/snap/lxd/common/lxd/logs/vm-test/qemu.conf -pidfile /var/snap/lxd/common/lxd/logs/vm-test/qemu.pid -D /var/snap/lxd/common/lxd/logs/vm-test/qemu.log -chroot /var/snap/lxd/common/lxd/virtual-machines/vm-test -smbios type=2,manufacturer=Canonical Ltd.,product=LXD -runas lxd: : exit status 1

Name: vm-test
Location: 1804.dev.bysh.me
Remote: unix://
Architecture: x86_64
Created: 2020/08/19 09:12 UTC
Status: Stopped
Type: virtual-machine
Profiles: default

Log:

Could not access KVM kernel module: No such file or directory
qemu-system-x86_64: failed to initialize kvm: No such file or directory

Any clue what I’m doing wrong?

Hmm, do you have a /dev/kvm device?

You may also want to do dmesg | grep kvm to see if the kernel reported anything about it. It could be that VT support is hardware disabled for example.

root@dream:~# cat /var/log/kern.log | grep kvm -i

root@dream:~# ls -la /dev/kvm
crw-rw---- 1 root kvm 10, 232 Aug 19 12:24 /dev/kvm

Not sure what /dev/kvm should look like, this ok?

Yeah, that looks correct.

Can you show ls -lh /var/snap/lxd/common/mntns/dev/?

root@dream:~# ls -lh /var/snap/lxd/common/mntns/dev/
total 0
crw-r–r-- 1 root root 10, 235 Aug 19 12:24 autofs
drwxr-xr-x 2 root root 740 Aug 19 12:25 block
drwxr-xr-x 2 root root 240 Aug 19 12:24 bsg
crw-rw---- 1 root disk 10, 234 Aug 19 12:24 btrfs-control
drwxr-xr-x 3 root root 60 Aug 19 12:24 bus
drwxr-xr-x 2 root root 3.8K Aug 19 12:25 char
crw------- 1 root root 5, 1 Aug 19 12:25 console
lrwxrwxrwx 1 root root 11 Aug 19 12:24 core -> /proc/kcore
drwxr-xr-x 2 root root 60 Aug 19 12:24 cpu
crw------- 1 root root 10, 59 Aug 19 12:24 cpu_dma_latency
crw------- 1 root root 10, 203 Aug 19 12:24 cuse
drwxr-xr-x 7 root root 140 Aug 19 12:24 disk
brw-rw---- 1 root disk 253, 0 Aug 19 12:24 dm-0
drwxr-xr-x 3 root root 80 Aug 19 12:24 dri
crw------- 1 root root 10, 62 Aug 19 12:24 ecryptfs
crw-rw---- 1 root video 29, 0 Aug 19 12:24 fb0
lrwxrwxrwx 1 root root 13 Aug 19 12:24 fd -> /proc/self/fd
crw-rw-rw- 1 root root 1, 7 Aug 19 12:24 full
crw-rw-rw- 1 root root 10, 229 Aug 19 12:25 fuse
crw------- 1 root root 241, 0 Aug 19 12:24 hidraw0
crw------- 1 root root 241, 1 Aug 19 12:24 hidraw1
crw------- 1 root root 10, 228 Aug 19 12:24 hpet
drwxr-xr-x 2 root root 0 Aug 19 12:24 hugepages
crw------- 1 root root 10, 183 Aug 19 12:24 hwrng
crw------- 1 root root 89, 0 Aug 19 12:24 i2c-0
lrwxrwxrwx 1 root root 25 Aug 19 12:24 initctl -> /run/systemd/initctl/fifo
drwxr-xr-x 4 root root 180 Aug 19 12:24 input
crw------- 1 root root 239, 0 Aug 19 12:24 ipmi0
crw-r–r-- 1 root root 1, 11 Aug 19 12:24 kmsg
crw-rw---- 1 root kvm 10, 232 Aug 19 12:24 kvm
drwxr-xr-x 2 root root 60 Aug 19 12:24 lightnvm
lrwxrwxrwx 1 root root 28 Aug 19 12:24 log -> /run/systemd/journal/dev-log
crw-rw---- 1 root disk 10, 237 Aug 19 12:24 loop-control
brw-rw---- 1 root disk 7, 0 Aug 19 12:24 loop0
brw-rw---- 1 root disk 7, 1 Aug 19 12:24 loop1
brw-rw---- 1 root disk 7, 2 Aug 19 12:24 loop2
brw-rw---- 1 root disk 7, 3 Aug 19 12:24 loop3
brw-rw---- 1 root disk 7, 4 Aug 19 12:24 loop4
brw-rw---- 1 root disk 7, 5 Aug 19 12:24 loop5
brw-rw---- 1 root disk 7, 6 Aug 19 12:24 loop6
brw-rw---- 1 root disk 7, 7 Aug 19 12:24 loop7
brw-rw---- 1 root disk 7, 8 Aug 19 12:24 loop8
brw-rw---- 1 root disk 7, 9 Aug 19 12:24 loop9
drwxr-xr-x 2 root root 80 Aug 19 12:24 mapper
crw------- 1 root root 10, 227 Aug 19 12:24 mcelog
brw-rw---- 1 root disk 9, 0 Aug 19 12:24 md0
crw-r----- 1 root kmem 1, 1 Aug 19 12:24 mem
drwxrwxrwt 2 root root 40 Aug 19 12:24 mqueue
drwxr-xr-x 2 root root 60 Aug 19 12:24 net
crw-rw-rw- 1 root root 1, 3 Aug 19 12:24 null
crw------- 1 root root 10, 144 Aug 19 12:24 nvram
crw-r----- 1 root kmem 1, 4 Aug 19 12:24 port
crw------- 1 root root 108, 0 Aug 19 12:24 ppp
crw------- 1 root root 10, 1 Aug 19 12:24 psaux
crw-rw-rw- 1 root root 5, 2 Aug 19 12:24 ptmx
crw------- 1 root root 246, 0 Aug 19 12:24 ptp0
crw------- 1 root root 246, 1 Aug 19 12:24 ptp1
drwxr-xr-x 2 root root 0 Aug 19 12:24 pts
crw-rw-rw- 1 root root 1, 8 Aug 19 12:24 random
drwxr-xr-x 3 root root 60 Aug 19 12:25 rbd
brw-rw---- 1 root disk 252, 0 Aug 19 12:25 rbd0
crw-rw-r-- 1 root root 10, 242 Aug 19 12:24 rfkill
lrwxrwxrwx 1 root root 4 Aug 19 12:24 rtc -> rtc0
crw------- 1 root root 249, 0 Aug 19 12:24 rtc0
brw-rw---- 1 root disk 8, 0 Aug 19 12:24 sda
brw-rw---- 1 root disk 8, 1 Aug 19 12:24 sda1
brw-rw---- 1 root disk 8, 16 Aug 19 12:24 sdb
brw-rw---- 1 root disk 8, 17 Aug 19 12:24 sdb1
brw-rw---- 1 root disk 8, 32 Aug 19 12:24 sdc
brw-rw---- 1 root disk 8, 33 Aug 19 12:24 sdc1
brw-rw---- 1 root disk 8, 48 Aug 19 12:24 sdd
brw-rw---- 1 root disk 8, 49 Aug 19 12:24 sdd1
brw-rw---- 1 root disk 8, 64 Aug 19 12:24 sde
brw-rw---- 1 root disk 8, 65 Aug 19 12:24 sde1
brw-rw---- 1 root disk 8, 80 Aug 19 12:24 sdf
brw-rw---- 1 root disk 8, 81 Aug 19 12:24 sdf1
brw-rw---- 1 root disk 8, 96 Aug 19 12:24 sdg
brw-rw---- 1 root disk 8, 97 Aug 19 12:24 sdg1
brw-rw---- 1 root disk 8, 98 Aug 19 12:24 sdg2
brw-rw---- 1 root disk 8, 99 Aug 19 12:24 sdg3
brw-rw---- 1 root disk 8, 112 Aug 19 12:24 sdh
brw-rw---- 1 root disk 8, 113 Aug 19 12:24 sdh1
brw-rw---- 1 root disk 8, 128 Aug 19 12:24 sdi
brw-rw---- 1 root disk 8, 129 Aug 19 12:24 sdi1
brw-rw---- 1 root disk 8, 144 Aug 19 12:24 sdj
brw-rw---- 1 root disk 8, 145 Aug 19 12:24 sdj1
crw-rw---- 1 root disk 21, 0 Aug 19 12:24 sg0
crw-rw---- 1 root disk 21, 1 Aug 19 12:24 sg1
crw-rw---- 1 root disk 21, 2 Aug 19 12:24 sg2
crw-rw---- 1 root disk 21, 3 Aug 19 12:24 sg3
crw-rw---- 1 root disk 21, 4 Aug 19 12:24 sg4
crw-rw---- 1 root disk 21, 5 Aug 19 12:24 sg5
crw-rw---- 1 root disk 21, 6 Aug 19 12:24 sg6
crw-rw---- 1 root disk 21, 7 Aug 19 12:24 sg7
crw-rw---- 1 root disk 21, 8 Aug 19 12:24 sg8
crw-rw---- 1 root disk 21, 9 Aug 19 12:24 sg9
drwxrwxrwt 2 root root 40 Aug 19 12:24 shm
crw------- 1 root root 10, 231 Aug 19 12:24 snapshot
drwxr-xr-x 2 root root 80 Aug 19 12:24 snd
lrwxrwxrwx 1 root root 15 Aug 19 12:24 stderr -> /proc/self/fd/2
lrwxrwxrwx 1 root root 15 Aug 19 12:24 stdin -> /proc/self/fd/0
lrwxrwxrwx 1 root root 15 Aug 19 12:24 stdout -> /proc/self/fd/1
crw-rw-rw- 1 root tty 5, 0 Aug 19 12:24 tty
crw–w---- 1 root tty 4, 0 Aug 19 12:24 tty0
crw–w---- 1 root tty 4, 1 Aug 19 12:25 tty1
crw–w---- 1 root tty 4, 10 Aug 19 12:24 tty10
crw–w---- 1 root tty 4, 11 Aug 19 12:24 tty11
crw–w---- 1 root tty 4, 12 Aug 19 12:24 tty12
crw–w---- 1 root tty 4, 13 Aug 19 12:24 tty13
crw–w---- 1 root tty 4, 14 Aug 19 12:24 tty14
crw–w---- 1 root tty 4, 15 Aug 19 12:24 tty15
crw–w---- 1 root tty 4, 16 Aug 19 12:24 tty16
crw–w---- 1 root tty 4, 17 Aug 19 12:24 tty17
crw–w---- 1 root tty 4, 18 Aug 19 12:24 tty18
crw–w---- 1 root tty 4, 19 Aug 19 12:24 tty19
crw–w---- 1 root tty 4, 2 Aug 19 12:24 tty2
crw–w---- 1 root tty 4, 20 Aug 19 12:24 tty20
crw–w---- 1 root tty 4, 21 Aug 19 12:24 tty21
crw–w---- 1 root tty 4, 22 Aug 19 12:24 tty22
crw–w---- 1 root tty 4, 23 Aug 19 12:24 tty23
crw–w---- 1 root tty 4, 24 Aug 19 12:24 tty24
crw–w---- 1 root tty 4, 25 Aug 19 12:24 tty25
crw–w---- 1 root tty 4, 26 Aug 19 12:24 tty26
crw–w---- 1 root tty 4, 27 Aug 19 12:24 tty27
crw–w---- 1 root tty 4, 28 Aug 19 12:24 tty28
crw–w---- 1 root tty 4, 29 Aug 19 12:24 tty29
crw–w---- 1 root tty 4, 3 Aug 19 12:24 tty3
crw–w---- 1 root tty 4, 30 Aug 19 12:24 tty30
crw–w---- 1 root tty 4, 31 Aug 19 12:24 tty31
crw–w---- 1 root tty 4, 32 Aug 19 12:24 tty32
crw–w---- 1 root tty 4, 33 Aug 19 12:24 tty33
crw–w---- 1 root tty 4, 34 Aug 19 12:24 tty34
crw–w---- 1 root tty 4, 35 Aug 19 12:24 tty35
crw–w---- 1 root tty 4, 36 Aug 19 12:24 tty36
crw–w---- 1 root tty 4, 37 Aug 19 12:24 tty37
crw–w---- 1 root tty 4, 38 Aug 19 12:24 tty38
crw–w---- 1 root tty 4, 39 Aug 19 12:24 tty39
crw–w---- 1 root tty 4, 4 Aug 19 12:24 tty4
crw–w---- 1 root tty 4, 40 Aug 19 12:24 tty40
crw–w---- 1 root tty 4, 41 Aug 19 12:24 tty41
crw–w---- 1 root tty 4, 42 Aug 19 12:24 tty42
crw–w---- 1 root tty 4, 43 Aug 19 12:24 tty43
crw–w---- 1 root tty 4, 44 Aug 19 12:24 tty44
crw–w---- 1 root tty 4, 45 Aug 19 12:24 tty45
crw–w---- 1 root tty 4, 46 Aug 19 12:24 tty46
crw–w---- 1 root tty 4, 47 Aug 19 12:24 tty47
crw–w---- 1 root tty 4, 48 Aug 19 12:24 tty48
crw–w---- 1 root tty 4, 49 Aug 19 12:24 tty49
crw–w---- 1 root tty 4, 5 Aug 19 12:24 tty5
crw–w---- 1 root tty 4, 50 Aug 19 12:24 tty50
crw–w---- 1 root tty 4, 51 Aug 19 12:24 tty51
crw–w---- 1 root tty 4, 52 Aug 19 12:24 tty52
crw–w---- 1 root tty 4, 53 Aug 19 12:24 tty53
crw–w---- 1 root tty 4, 54 Aug 19 12:24 tty54
crw–w---- 1 root tty 4, 55 Aug 19 12:24 tty55
crw–w---- 1 root tty 4, 56 Aug 19 12:24 tty56
crw–w---- 1 root tty 4, 57 Aug 19 12:24 tty57
crw–w---- 1 root tty 4, 58 Aug 19 12:24 tty58
crw–w---- 1 root tty 4, 59 Aug 19 12:24 tty59
crw–w---- 1 root tty 4, 6 Aug 19 12:24 tty6
crw–w---- 1 root tty 4, 60 Aug 19 12:24 tty60
crw–w---- 1 root tty 4, 61 Aug 19 12:24 tty61
crw–w---- 1 root tty 4, 62 Aug 19 12:24 tty62
crw–w---- 1 root tty 4, 63 Aug 19 12:24 tty63
crw–w---- 1 root tty 4, 7 Aug 19 12:24 tty7
crw–w---- 1 root tty 4, 8 Aug 19 12:24 tty8
crw–w---- 1 root tty 4, 9 Aug 19 12:24 tty9
crw-rw---- 1 root dialout 4, 64 Aug 19 12:24 ttyS0
crw-rw---- 1 root dialout 4, 65 Aug 19 12:24 ttyS1
crw-rw---- 1 root dialout 4, 74 Aug 19 12:24 ttyS10
crw-rw---- 1 root dialout 4, 75 Aug 19 12:24 ttyS11
crw-rw---- 1 root dialout 4, 76 Aug 19 12:24 ttyS12
crw-rw---- 1 root dialout 4, 77 Aug 19 12:24 ttyS13
crw-rw---- 1 root dialout 4, 78 Aug 19 12:24 ttyS14
crw-rw---- 1 root dialout 4, 79 Aug 19 12:24 ttyS15
crw-rw---- 1 root dialout 4, 80 Aug 19 12:24 ttyS16
crw-rw---- 1 root dialout 4, 81 Aug 19 12:24 ttyS17
crw-rw---- 1 root dialout 4, 82 Aug 19 12:24 ttyS18
crw-rw---- 1 root dialout 4, 83 Aug 19 12:24 ttyS19
crw-rw---- 1 root dialout 4, 66 Aug 19 12:24 ttyS2
crw-rw---- 1 root dialout 4, 84 Aug 19 12:24 ttyS20
crw-rw---- 1 root dialout 4, 85 Aug 19 12:24 ttyS21
crw-rw---- 1 root dialout 4, 86 Aug 19 12:24 ttyS22
crw-rw---- 1 root dialout 4, 87 Aug 19 12:24 ttyS23
crw-rw---- 1 root dialout 4, 88 Aug 19 12:24 ttyS24
crw-rw---- 1 root dialout 4, 89 Aug 19 12:24 ttyS25
crw-rw---- 1 root dialout 4, 90 Aug 19 12:24 ttyS26
crw-rw---- 1 root dialout 4, 91 Aug 19 12:24 ttyS27
crw-rw---- 1 root dialout 4, 92 Aug 19 12:24 ttyS28
crw-rw---- 1 root dialout 4, 93 Aug 19 12:24 ttyS29
crw-rw---- 1 root dialout 4, 67 Aug 19 12:24 ttyS3
crw-rw---- 1 root dialout 4, 94 Aug 19 12:24 ttyS30
crw-rw---- 1 root dialout 4, 95 Aug 19 12:24 ttyS31
crw-rw---- 1 root dialout 4, 68 Aug 19 12:24 ttyS4
crw-rw---- 1 root dialout 4, 69 Aug 19 12:24 ttyS5
crw-rw---- 1 root dialout 4, 70 Aug 19 12:24 ttyS6
crw-rw---- 1 root dialout 4, 71 Aug 19 12:24 ttyS7
crw-rw---- 1 root dialout 4, 72 Aug 19 12:24 ttyS8
crw-rw---- 1 root dialout 4, 73 Aug 19 12:24 ttyS9
crw------- 1 root root 5, 3 Aug 19 12:24 ttyprintk
crw------- 1 root root 10, 60 Aug 19 12:24 udmabuf
crw------- 1 root root 10, 223 Aug 19 12:24 uinput
crw-rw-rw- 1 root root 1, 9 Aug 19 12:24 urandom
crw-rw---- 1 root tty 7, 0 Aug 19 12:24 vcs
crw-rw---- 1 root tty 7, 1 Aug 19 12:24 vcs1
crw-rw---- 1 root tty 7, 2 Aug 19 12:24 vcs2
crw-rw---- 1 root tty 7, 3 Aug 19 12:24 vcs3
crw-rw---- 1 root tty 7, 4 Aug 19 12:24 vcs4
crw-rw---- 1 root tty 7, 5 Aug 19 12:24 vcs5
crw-rw---- 1 root tty 7, 6 Aug 19 12:24 vcs6
crw-rw---- 1 root tty 7, 128 Aug 19 12:24 vcsa
crw-rw---- 1 root tty 7, 129 Aug 19 12:24 vcsa1
crw-rw---- 1 root tty 7, 130 Aug 19 12:24 vcsa2
crw-rw---- 1 root tty 7, 131 Aug 19 12:24 vcsa3
crw-rw---- 1 root tty 7, 132 Aug 19 12:24 vcsa4
crw-rw---- 1 root tty 7, 133 Aug 19 12:24 vcsa5
crw-rw---- 1 root tty 7, 134 Aug 19 12:24 vcsa6
crw-rw---- 1 root tty 7, 64 Aug 19 12:24 vcsu
crw-rw---- 1 root tty 7, 65 Aug 19 12:24 vcsu1
crw-rw---- 1 root tty 7, 66 Aug 19 12:24 vcsu2
crw-rw---- 1 root tty 7, 67 Aug 19 12:24 vcsu3
crw-rw---- 1 root tty 7, 68 Aug 19 12:24 vcsu4
crw-rw---- 1 root tty 7, 69 Aug 19 12:24 vcsu5
crw-rw---- 1 root tty 7, 70 Aug 19 12:24 vcsu6
drwxr-xr-x 2 root root 60 Aug 19 12:24 vfio
drwxr-xr-x 2 root root 60 Aug 19 12:24 vg0
crw------- 1 root root 10, 63 Aug 19 12:24 vga_arbiter
crw------- 1 root root 10, 238 Aug 19 12:24 vhost-net
crw------- 1 root root 10, 241 Aug 19 12:24 vhost-vsock
crw-rw-rw- 1 root root 1, 5 Aug 19 12:24 zero
crw------- 1 root root 10, 249 Aug 19 12:25 zfs

Ok, so the device is definitely there… not sure what it’s complaining about then.

The relevant code in qemu is:

    s->fd = qemu_open("/dev/kvm", O_RDWR);
    if (s->fd == -1) {
        fprintf(stderr, "Could not access KVM kernel module: %m\n");
        ret = -errno;
        goto err;
    }

So I’m pretty confused as to why this fails for you given the device exists…

Can you try:

nsenter -t $(cat /var/snap/lxd/common/lxd.pid) -m ls -lh /dev/kvm
nsenter -t $(cat /var/snap/lxd/common/lxd.pid) -m cat /dev/kvm

Sure thing, that latter does not look promising.

root@dream:~# nsenter -t $(cat /var/snap/lxd/common/lxd.pid) -m ls -lh /dev/kvm
crw-rw---- 1 root kvm 10, 232 Aug 19 12:24 /dev/kvm
root@dream:~# nsenter -t $(cat /var/snap/lxd/common/lxd.pid) -m cat /dev/kvm
cat: /dev/kvm: Invalid argument

Ok, so that’s behaving normally. /dev/kvm can only be interacted with through ioctl, so it’s normal that cat fails, I wanted to make sure it fails the expected way :slight_smile:

I take it you’ve confirmed that you are still getting the start error now?

Just did a lxc start vm-test again and it fails still.

That’s so weird…

Anything useful in dmesg?

I cleared dmesg yesterday morning on this server. Right now all that’s in there is.

[56420.608552] kauditd_printk_skb: 7 callbacks suppressed
[56420.608556] audit: type=1400 audit(1597889103.621:85): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/core/9804/usr/lib/snapd/snap-confine" pid=21923 comm="apparmor_parser"
[56420.608564] audit: type=1400 audit(1597889103.621:86): apparmor="STATUS" operation="profile_replace" info="same as current profile, skipping" profile="unconfined" name="/snap/core/9804/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=21923 comm="apparmor_parser"
[56420.719949] audit: type=1400 audit(1597889103.733:87): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.hook.install" pid=21931 comm="apparmor_parser"
[56420.733151] audit: type=1400 audit(1597889103.745:88): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.buginfo" pid=21927 comm="apparmor_parser"
[56420.733841] audit: type=1400 audit(1597889103.749:89): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.benchmark" pid=21926 comm="apparmor_parser"
[56420.735690] audit: type=1400 audit(1597889103.749:90): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.activate" pid=21925 comm="apparmor_parser"
[56420.736100] audit: type=1400 audit(1597889103.749:91): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.lxd" pid=21935 comm="apparmor_parser"
[56420.736713] audit: type=1400 audit(1597889103.749:92): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.lxc-to-lxd" pid=21934 comm="apparmor_parser"
[56420.737027] audit: type=1400 audit(1597889103.749:93): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.hook.remove" pid=21932 comm="apparmor_parser"
[56420.737426] audit: type=1400 audit(1597889103.753:94): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="snap.lxd.check-kernel" pid=21928 comm="apparmor_parser"
[64826.049769] new mount options do not match the existing superblock, will be ignored

Calling start again does not make new lines show up :frowning:

Ok, that looks normal.

So I guess time for the big hammer to figure it out…
In a separate terminal, run sudo strace -f -o trace -p $(cat /var/snap/lxd/common/lxd.pid)
Then run a lxc start in a separate terminal.
Then ctrl+c the strace

That should leave you with a rather large trace file that hopefully will show us what’s going on.

I’ve uploaded the trace here.

Edit: tried to look for clues but came up dry. :frowning:

Yeah, that’s a bit of a weird one as I don’t see it even trying to run qemu…
Can you show lxc info on that system?

lxc info
config:
  cluster.https_address: X:8443
  core.https_address: X:8443
  core.trust_password: true
  images.auto_update_interval: "0"
api_extensions:
- storage_zfs_remove_snapshots
- container_host_shutdown_timeout
- container_stop_priority
- container_syscall_filtering
- auth_pki
- container_last_used_at
- etag
- patch
- usb_devices
- https_allowed_credentials
- image_compression_algorithm
- directory_manipulation
- container_cpu_time
- storage_zfs_use_refquota
- storage_lvm_mount_options
- network
- profile_usedby
- container_push
- container_exec_recording
- certificate_update
- container_exec_signal_handling
- gpu_devices
- container_image_properties
- migration_progress
- id_map
- network_firewall_filtering
- network_routes
- storage
- file_delete
- file_append
- network_dhcp_expiry
- storage_lvm_vg_rename
- storage_lvm_thinpool_rename
- network_vlan
- image_create_aliases
- container_stateless_copy
- container_only_migration
- storage_zfs_clone_copy
- unix_device_rename
- storage_lvm_use_thinpool
- storage_rsync_bwlimit
- network_vxlan_interface
- storage_btrfs_mount_options
- entity_description
- image_force_refresh
- storage_lvm_lv_resizing
- id_map_base
- file_symlinks
- container_push_target
- network_vlan_physical
- storage_images_delete
- container_edit_metadata
- container_snapshot_stateful_migration
- storage_driver_ceph
- storage_ceph_user_name
- resource_limits
- storage_volatile_initial_source
- storage_ceph_force_osd_reuse
- storage_block_filesystem_btrfs
- resources
- kernel_limits
- storage_api_volume_rename
- macaroon_authentication
- network_sriov
- console
- restrict_devlxd
- migration_pre_copy
- infiniband
- maas_network
- devlxd_events
- proxy
- network_dhcp_gateway
- file_get_symlink
- network_leases
- unix_device_hotplug
- storage_api_local_volume_handling
- operation_description
- clustering
- event_lifecycle
- storage_api_remote_volume_handling
- nvidia_runtime
- container_mount_propagation
- container_backup
- devlxd_images
- container_local_cross_pool_handling
- proxy_unix
- proxy_udp
- clustering_join
- proxy_tcp_udp_multi_port_handling
- network_state
- proxy_unix_dac_properties
- container_protection_delete
- unix_priv_drop
- pprof_http
- proxy_haproxy_protocol
- network_hwaddr
- proxy_nat
- network_nat_order
- container_full
- candid_authentication
- backup_compression
- candid_config
- nvidia_runtime_config
- storage_api_volume_snapshots
- storage_unmapped
- projects
- candid_config_key
- network_vxlan_ttl
- container_incremental_copy
- usb_optional_vendorid
- snapshot_scheduling
- container_copy_project
- clustering_server_address
- clustering_image_replication
- container_protection_shift
- snapshot_expiry
- container_backup_override_pool
- snapshot_expiry_creation
- network_leases_location
- resources_cpu_socket
- resources_gpu
- resources_numa
- kernel_features
- id_map_current
- event_location
- storage_api_remote_volume_snapshots
- network_nat_address
- container_nic_routes
- rbac
- cluster_internal_copy
- seccomp_notify
- lxc_features
- container_nic_ipvlan
- network_vlan_sriov
- storage_cephfs
- container_nic_ipfilter
- resources_v2
- container_exec_user_group_cwd
- container_syscall_intercept
- container_disk_shift
- storage_shifted
- resources_infiniband
- daemon_storage
- instances
- image_types
- resources_disk_sata
- clustering_roles
- images_expiry
- resources_network_firmware
- backup_compression_algorithm
- ceph_data_pool_name
- container_syscall_intercept_mount
- compression_squashfs
- container_raw_mount
- container_nic_routed
- container_syscall_intercept_mount_fuse
- container_disk_ceph
- virtual-machines
- image_profiles
- clustering_architecture
- resources_disk_id
- storage_lvm_stripes
- vm_boot_priority
- unix_hotplug_devices
- api_filtering
- instance_nic_network
- clustering_sizing
- firewall_driver
- projects_limits
- container_syscall_intercept_hugetlbfs
- limits_hugepages
- container_nic_routed_gateway
- projects_restrictions
- custom_volume_snapshot_expiry
- volume_snapshot_scheduling
- trust_ca_certificates
- snapshot_disk_usage
- clustering_edit_roles
- container_nic_routed_host_address
- container_nic_ipvlan_gateway
- resources_usb_pci
- resources_cpu_threads_numa
- resources_cpu_core_die
- api_os
- container_nic_routed_host_table
- container_nic_ipvlan_host_table
- container_nic_ipvlan_mode
- resources_system
- images_push_relay
- network_dns_search
- container_nic_routed_limits
- instance_nic_bridged_vlan
- network_state_bond_bridge
- usedby_consistency
- custom_block_volumes
- clustering_failure_domains
- resources_gpu_mdev
- console_vga_type
- projects_limits_disk
- network_type_macvlan
- network_type_sriov
api_status: stable
api_version: "1.0"
auth: trusted
public: false
auth_methods:
- tls
environment:
  addresses:
  - X:8443
  architectures:
  - x86_64
  - i686
  certificate: |
    -----BEGIN CERTIFICATE-----
    omitted
    -----END CERTIFICATE-----
  certificate_fingerprint: 57e6d38c216b0a4c8790940f5b7450a45aa4f68b450c2609c103476c2ac06e32
  driver: lxc
  driver_version: 4.0.4
  firewall: xtables
  kernel: Linux
  kernel_architecture: x86_64
  kernel_features:
    netnsid_getifaddrs: "true"
    seccomp_listener: "true"
    seccomp_listener_continue: "true"
    shiftfs: "false"
    uevent_injection: "true"
    unpriv_fscaps: "true"
  kernel_version: 5.4.0-42-generic
  lxc_features:
    cgroup2: "true"
    devpts_fd: "false"
    mount_injection_file: "true"
    network_gateway_device_route: "true"
    network_ipvlan: "true"
    network_l2proxy: "true"
    network_phys_macvlan_mtu: "true"
    network_veth_router: "true"
    pidfd: "true"
    seccomp_allow_deny_syntax: "true"
    seccomp_notify: "true"
    seccomp_proxy_send_notify_fd: "false"
  os_name: Ubuntu
  os_version: "18.04"
  project: default
  server: lxd
  server_clustered: true
  server_name: dream
  server_pid: 22262
  server_version: "4.4"
  storage: ceph
  storage_version: ceph version 12.2.13 (584a20eb0237c657dc0567da126be145106aa47e) luminous (stable)

This pops out to me

driver: lxc
driver_version: 4.0.4

Shouldn’t that also be 4.4?

root@dream:~# lxc version
Client version: 4.4
Server version: 4.4

No, that’s okay.
What pops at me instead is that you’re using a cluster :slight_smile:
How many systems do you have in that cluster?

LXD automatically balances new instances, so what you’re seeing could be simply explained by whatever server is actually selected not supporting VMs.

You could try to launch a new VM passing --target dream to lxc launch to ensure it’s on the system you’ve validated.