[libvirt-users] Failed to access the console after starting the lxc container
Hello, I am starting the system container without "/" directory So that it can share the host /bin /sbin /lib and /lib64 and i have sepeartely mounted /var, /etc and /usr directory for the container Below is xml file <domain type='lxc'> <name>test6</name> <memory>102400</memory> <os> <type>exe</type> <init>/sbin/init</init> </os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <console type='pty'/> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/etc'/> <target dir='/etc'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/var'/> <target dir='/var'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/usr'/> <target dir='/usr'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/pg_data/'/> <target dir='/pg_data'/> </filesystem> <filesystem type='ram' accessmode='passthrough'> <source usage='0' units='KiB'/> <target dir='/dev/shm'/> </filesystem> <interface type='bridge'> <source bridge='br0' /> </interface> </devices> </domain> when i start the container it get start , but when i try to access console it get stuck virsh # list Id Name State ---------------------------------------------------- 18238 test4 running 20435 test6 running virsh # virsh # start test6 Domain test6 started virsh # console test6 Connected to domain test6 Escape character is ^] But when i mount the "/" in xml it works, i have also share host /bin,/sbin, /lib and /lib64. <domain type='lxc'> <name>test4</name> <memory>102400</memory> <os> <type>exe</type> <init>/sbin/init</init> </os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <console type='pty'/> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test4/'/> <target dir='/'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/bin'/> <target dir='/bin'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/sbin'/> <target dir='/sbin'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/lib'/> <target dir='/lib'/> </filesystem> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/lib64'/> <target dir='/lib64'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/pg_data/'/> <target dir='/pg_data'/> </filesystem> <filesystem type='ram' accessmode='passthrough'> <source usage='0' units='KiB'/> <target dir='/dev/shm'/> </filesystem> <interface type='bridge'> <source bridge='br0' /> </interface> </devices> </domain> as i am new , can anyone explain me why my test6 container get stuck? And in system container if we need to share host filesystem y we need to mount them explicitly? Thanks, Aarti Sawant NTTDATA OSS Center Pune
On Wed, Nov 20, 2013 at 05:28:29PM +0530, Aarti Sawant wrote:
Hello,
I am starting the system container without "/" directory So that it can share the host /bin /sbin /lib and /lib64 and i have sepeartely mounted /var, /etc and /usr directory for the container Below is xml file <domain type='lxc'> <name>test6</name> <memory>102400</memory> <os> <type>exe</type> <init>/sbin/init</init>
Ok, so you're starting a real "init" process. By default this won't respond to any input on the console. You need to make sure that your init system is setup to start a mingtty process on the console. Typically if you're trying to share the '/' diretory between the host & container though, you don't want to run a full "init" system. Instead you'd want to just run a specific application binary instead. In fact I'd go as far to recommend against running 'init' if you're sharing '/'. That said, I see you're setting up private /etc & /var so you should be mostly OK from a writable file clash POV. If you want a full OS container installed to a new location though, I've got a guide for this https://www.berrange.com/posts/2013/08/12/running-a-full-fedora-os-inside-a-...
</os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash>
<devices> <console type='pty'/> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/etc'/> <target dir='/etc'/> </filesystem>
<filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/var'/> <target dir='/var'/> </filesystem> <filesystem type='mount' accessmode='passthrough'> <source dir='/lxc/test6/usr'/> <target dir='/usr'/> </filesystem>
<filesystem type='mount' accessmode='passthrough'> <source dir='/pg_data/'/> <target dir='/pg_data'/> </filesystem>
<filesystem type='ram' accessmode='passthrough'> <source usage='0' units='KiB'/> <target dir='/dev/shm'/> </filesystem> <interface type='bridge'> <source bridge='br0' /> </interface> </devices> </domain>
when i start the container it get start , but when i try to access console it get stuck
Basically you need to see why the mingetty processes aren't being started. On F19 with systemd, it should all 'just work' from a console POV, aside from needing to edit /etc/securetty to allow root login per my blog above.
virsh # list Id Name State ---------------------------------------------------- 18238 test4 running 20435 test6 running
virsh #
virsh # start test6 Domain test6 started
virsh # console test6 Connected to domain test6 Escape character is ^]
But when i mount the "/" in xml it works, i have also share host /bin,/sbin, /lib and /lib64.
That should not make any difference, at least with a fairly recent libvirt. If you don't have any <filesystem> listed with a target of '/', then libvirt will secretly add one using source=/ and target=/. You don't mention what version of libvirt / kernel, or host OS you have here btw. That would be generally useful info for troubleshooting this. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
participants (2)
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Aarti Sawant -
Daniel P. Berrange