On Mon, Jun 10, 2013 at 09:07:08AM +0800, Gao feng wrote:

...

On 06/09/2013 08:14 PM, pr.G wrote:

...

Hello.

Is it possible to start container via libvirt_lxc without mounting /sys inside container?

When I start container via lxc-start and do not add mount point to config, then /sys inside container is empty.

When I do it via virsh -c lxc:// container.xml, then /sys contains sysfs of the host and /sys on host becomes remounting read-only.

how can it be true? Can you post your /proc/mounts on host and container?

...

Am I doing something wrong or is this feature of libvirt_lxc?

Absolutely it's not a feature.

Thanks!

Thanks for the quick reply. I was surprised too. I didn't post /proc/mounts to container.

On Mon, Jun 10, 2013 at 09:29:32AM +0400, свящ. Георгий Гольцов wrote: libvirt_lxc did it for me. I read http://libvirt.org/drvlxc.html about Filesystem mounts: " In the absence of any explicit configuration, the container will inherit the host OS filesystem mounts. A number of mount points will be made read only, or re-mounted with new instances to provide container specific data. The following special mounts are setup by libvirt * /dev a new "tmpfs" pre-populated with authorized device nodes * /dev/pts a new private "devpts" instance for console devices * /sys the host "sysfs" instance remounted read-only * /proc a new instance of the "proc" filesystem * /proc/sys the host "/proc/sys" bind-mounted read-only * /sys/fs/selinux the host "selinux" instance remounted read-only * /sys/fs/cgroup/NNNN the host cgroups controllers bind-mounted to * only expose the sub-tree associated with the container * /proc/meminfo a FUSE backed file reflecting memory limits of the * container " Can I disable this behavior? How do I specify an explicit configuration? Thanks. my container.xml: (The entire xml file is shown in the my original post)

... <devices> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/var/lxc/ns1/rootfs'/> <target dir='/'/> </filesystem> ... </device> ...

...

...

Thanks.

root@host:~# uname -a Linux host 3.2.0-4-amd64 #1 SMP Debian 3.2.41-2+deb7u2 x86_64 GNU/Linux

root@host:~# cat /etc/os-release PRETTY_NAME="Debian GNU/Linux 7.0 (wheezy)" ...

root@host:~# dpkg -l | grep libvirt ii libvirt-bin 0.9.12-11 amd64 programs for the libvirt library ii libvirt0 0.9.12-11 amd64 library for interfacing with different virtualization systems

container.xml: <domain type='lxc'> <name>ns1</name> <memory>524288</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> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/var/lxc/ns1/rootfs'/> <target dir='/'/> </filesystem> <interface type='bridge'> <source bridge='br0'/> <mac address='52:54:00:de:74:06'/> </interface> <console type='pty' /> </devices> </domain>

_______________________________________________ libvirt-users mailing list libvirt-users@redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users

On Mon, Jun 10, 2013 at 01:58:29PM +0800, Gao feng wrote:

On 06/10/2013 01:41 PM, pr.G wrote:

...

On Mon, Jun 10, 2013 at 09:29:32AM +0400, свящ. Георгий Гольцов wrote:

...

On Mon, Jun 10, 2013 at 09:07:08AM +0800, Gao feng wrote:

...

On 06/09/2013 08:14 PM, pr.G wrote:

...

Hello.

Is it possible to start container via libvirt_lxc without mounting /sys inside container?

When I start container via lxc-start and do not add mount point to config, then /sys inside container is empty.

When I do it via virsh -c lxc:// container.xml, then /sys contains sysfs of the host and /sys on host becomes remounting read-only.

how can it be true? Can you post your /proc/mounts on host and container?

...

Am I doing something wrong or is this feature of libvirt_lxc?

Absolutely it's not a feature.

Thanks!

Thanks for the quick reply. I was surprised too. I didn't post /proc/mounts to container.

I mean show the /proc/mounts of container and host

in container: cat /proc/mounts

[root@Donkey /]# cat /proc/mounts rootfs / rootfs rw 0 0 devpts /dev/pts devpts rw,nosuid,relatime,gid=5,mode=620,ptmxmode=666 0 0 devfs /dev tmpfs rw,nosuid,relatime,size=64k,mode=755 0 0 /dev/sdb2 / ext4 rw,relatime,data=ordered 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 proc /proc/sys proc ro,relatime 0 0 sysfs /sys sysfs ro,relatime 0 0 libvirt /proc/meminfo fuse rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other 0 0 tmpfs /sys/fs/cgroup tmpfs rw,nosuid,nodev,noexec,relatime,size=64k,mode=755,uid=1000,gid=1000 0 0 cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpuacct,cpu 0 0 cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0 cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory 0 0 cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0 cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0 cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0 cgroup /sys/fs/cgroup/net_cls cgroup rw,nosuid,nodev,noexec,relatime,net_cls 0 0 cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event 0 0 devpts /dev/ptmx devpts rw,nosuid,relatime,gid=5,mode=620,ptmxmode=666 0 0

in container: root@container:~# cat /proc/mounts rootfs / rootfs rw 0 0 devpts /dev/pts devpts rw,seclabel,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=666 0 0 /dev/mapper/vg0-var / ext4 rw,seclabel,relatime,user_xattr,barrier=1,data=ordered 0 0 devpts /dev/pts devpts rw,seclabel,nosuid,relatime,gid=5,mode=620,ptmxmode=666 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 proc /proc/sys proc ro,relatime 0 0 sysfs /sys sysfs ro,seclabel,relatime 0 0 devfs /dev tmpfs rw,seclabel,nosuid,relatime,size=64k,mode=755 0 0 devpts /dev/ptmx devpts rw,seclabel,nosuid,relatime,gid=5,mode=620,ptmxmode=666 0 0 selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0 tmpfs /run tmpfs rw,rootcontext=system_u:object_r:var_t:s0,seclabel,nosuid,noexec,relatime,size=6609200k,mode=755 0 0 tmpfs /run/lock tmpfs rw,rootcontext=system_u:object_r:var_t:s0,seclabel,nosuid,nodev,noexec,relatime,size=5120k 0 0 tmpfs /run/shm tmpfs rw,rootcontext=system_u:object_r:var_t:s0,seclabel,nosuid,nodev,noexec,relatime,size=32748940k 0 0

and in host [root@Donkey libvirt]# cat /proc/mounts rootfs / rootfs rw 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 devtmpfs /dev devtmpfs rw,nosuid,size=5081344k,nr_inodes=1270336,mode=755 0 0 securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0 tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0 devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 tmpfs /run tmpfs rw,nosuid,nodev,mode=755 0 0 tmpfs /sys/fs/cgroup tmpfs rw,nosuid,nodev,noexec,mode=755 0 0 cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd 0 0 pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0 cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0 cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpuacct,cpu 0 0 cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory 0 0 cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0 cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0 cgroup /sys/fs/cgroup/net_cls cgroup rw,nosuid,nodev,noexec,relatime,net_cls 0 0 cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0 cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event 0 0 cgroup /sys/fs/cgroup/hugetlb cgroup rw,nosuid,nodev,noexec,relatime,hugetlb 0 0 ....

in host root@host:~# cat /proc/mounts rootfs / rootfs rw 0 0 sysfs /sys sysfs rw,seclabel,nosuid,nodev,noexec,relatime 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 udev /dev devtmpfs rw,seclabel,relatime,size=10240k,nr_inodes=8251651,mode=755 0 0 devpts /dev/pts devpts rw,seclabel,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 tmpfs /run tmpfs rw,seclabel,nosuid,noexec,relatime,size=6609200k,mode=755 0 0 /dev/disk/by-uuid/14601dd5-89c4-46c9-aa88-dbfbfb1f092a / ext4 rw,seclabel,noatime,errors=remount-ro,user_xattr,barrier=1,data=ordered 0 0 selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0 tmpfs /run/lock tmpfs rw,rootcontext=system_u:object_r:var_lock_t:s0,seclabel,nosuid,nodev,noexec,relatime,size=5120k 0 0 tmpfs /run/shm tmpfs rw,rootcontext=system_u:object_r:tmpfs_t:s0,seclabel,nosuid,nodev,noexec,relatime,size=13218380k 0 0 ... /dev/mapper/vg0-var /var ext4 rw,seclabel,noatime,user_xattr,barrier=1,data=ordered 0 0 cgroup /sys/fs/cgroup cgroup rw,relatime,perf_event,blkio,net_cls,freezer,devices,memory,cpuacct,cpu,cpuset,clone_children 0 0 rpc_pipefs /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0

...

libvirt_lxc did it for me. I read http://libvirt.org/drvlxc.html about Filesystem mounts: " In the absence of any explicit configuration, the container will inherit the host OS filesystem mounts. A number of mount points will be made read only, or re-mounted with new instances to provide container specific data. The following special mounts are setup by libvirt

* /dev a new "tmpfs" pre-populated with authorized device nodes * /dev/pts a new private "devpts" instance for console devices * /sys the host "sysfs" instance remounted read-only * /proc a new instance of the "proc" filesystem * /proc/sys the host "/proc/sys" bind-mounted read-only * /sys/fs/selinux the host "selinux" instance remounted read-only * /sys/fs/cgroup/NNNN the host cgroups controllers bind-mounted to * only expose the sub-tree associated with the container * /proc/meminfo a FUSE backed file reflecting memory limits of the * container " Can I disable this behavior? How do I specify an explicit configuration?

This can't be disabled and it's no need to disable this.

...

my container.xml: (The entire xml file is shown in the my original post)

...

... <devices> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/var/lxc/ns1/rootfs'/> <target dir='/'/> </filesystem> ... </device> ...

Your configuration looks good, In container,the sysfs is mounted as read-only default. Since we don't want user in container to change some sysfs-configuration of host.

My problem was after first start lxc containet by virsh (after reboot host), the host /sys fs becomes ro. After I remount it rw manually and start container again, all OK: /sys in host - rw, in container - ro. Thanks, Gao. This problem was solved for me.

Thanks Gao.

...

...

...

...

Thanks.

root@host:~# uname -a Linux host 3.2.0-4-amd64 #1 SMP Debian 3.2.41-2+deb7u2 x86_64 GNU/Linux

root@host:~# cat /etc/os-release PRETTY_NAME="Debian GNU/Linux 7.0 (wheezy)" ...

root@host:~# dpkg -l | grep libvirt ii libvirt-bin 0.9.12-11 amd64 programs for the libvirt library ii libvirt0 0.9.12-11 amd64 library for interfacing with different virtualization systems

container.xml: <domain type='lxc'> <name>ns1</name> <memory>524288</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> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/var/lxc/ns1/rootfs'/> <target dir='/'/> </filesystem> <interface type='bridge'> <source bridge='br0'/> <mac address='52:54:00:de:74:06'/> </interface> <console type='pty' /> </devices> </domain>

_______________________________________________ libvirt-users mailing list libvirt-users@redhat.com https://www.redhat.com/mailman/listinfo/libvirt-users