10 pct - Tool to manage Linux Containers (LXC) on Proxmox VE
16 include::pct.1-synopsis.adoc[]
23 Proxmox Container Toolkit
24 =========================
28 :title: Linux Container
31 Containers are a lightweight alternative to fully virtualized machines (VMs).
32 They use the kernel of the host system that they run on, instead of emulating a
33 full operating system (OS). This means that containers can access resources on
34 the host system directly.
36 The runtime costs for containers is low, usually negligible. However, there are
37 some drawbacks that need be considered:
39 * Only Linux distributions can be run in Proxmox Containers. It is not possible to run
40 other operating systems like, for example, FreeBSD or Microsoft Windows
43 * For security reasons, access to host resources needs to be restricted.
44 Therefore, containers run in their own separate namespaces. Additionally some
45 syscalls (user space requests to the Linux kernel) are not allowed within containers.
47 {pve} uses https://linuxcontainers.org/lxc/introduction/[Linux Containers (LXC)] as its underlying
48 container technology. The ``Proxmox Container Toolkit'' (`pct`) simplifies the
49 usage and management of LXC, by providing an interface that abstracts
52 Containers are tightly integrated with {pve}. This means that they are aware of
53 the cluster setup, and they can use the same network and storage resources as
54 virtual machines. You can also use the {pve} firewall, or manage containers
55 using the HA framework.
57 Our primary goal is to offer an environment that provides the benefits of using a
58 VM, but without the additional overhead. This means that Proxmox Containers can
59 be categorized as ``System Containers'', rather than ``Application Containers''.
61 NOTE: If you want to run application containers, for example, 'Docker' images, it
62 is recommended that you run them inside a Proxmox Qemu VM. This will give you
63 all the advantages of application containerization, while also providing the
64 benefits that VMs offer, such as strong isolation from the host and the ability
65 to live-migrate, which otherwise isn't possible with containers.
71 * LXC (https://linuxcontainers.org/)
73 * Integrated into {pve} graphical web user interface (GUI)
75 * Easy to use command line tool `pct`
77 * Access via {pve} REST API
79 * 'lxcfs' to provide containerized /proc file system
81 * Control groups ('cgroups') for resource isolation and limitation
83 * 'AppArmor' and 'seccomp' to improve security
85 * Modern Linux kernels
87 * Image based deployment (xref:pct_supported_distributions[templates])
89 * Uses {pve} xref:chapter_storage[storage library]
91 * Container setup from host (network, DNS, storage, etc.)
94 [[pct_supported_distributions]]
95 Supported Distributions
96 -----------------------
98 List of officially supported distributions can be found below.
100 Templates for the following distributions are available through our
101 repositories. You can use xref:pct_container_images[pveam] tool or the
102 Graphical User Interface to download them.
107 [quote, 'https://alpinelinux.org']
109 Alpine Linux is a security-oriented, lightweight Linux distribution based on
110 musl libc and busybox.
113 https://alpinelinux.org/releases/
118 [quote, 'https://archlinux.org/']
120 Arch Linux, a lightweight and flexible Linux® distribution that tries to Keep It Simple.
124 CentOS, Almalinux, Rocky Linux
125 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
127 CentOS / CentOS Stream
128 ^^^^^^^^^^^^^^^^^^^^^^
130 [quote, 'https://centos.org']
132 The CentOS Linux distribution is a stable, predictable, manageable and
133 reproducible platform derived from the sources of Red Hat Enterprise Linux
137 https://wiki.centos.org/About/Product
142 [quote, 'https://almalinux.org']
144 An Open Source, community owned and governed, forever-free enterprise Linux
145 distribution, focused on long-term stability, providing a robust
146 production-grade platform. AlmaLinux OS is 1:1 binary compatible with RHEL® and
151 https://en.wikipedia.org/wiki/AlmaLinux#Releases
156 [quote, 'https://rockylinux.org']
158 Rocky Linux is a community enterprise operating system designed to be 100%
159 bug-for-bug compatible with America's top enterprise Linux distribution now
160 that its downstream partner has shifted direction.
163 https://en.wikipedia.org/wiki/Rocky_Linux#Releases
168 [quote, 'https://www.debian.org/intro/index#software']
170 Debian is a free operating system, developed and maintained by the Debian
171 project. A free Linux distribution with thousands of applications to meet our
175 https://www.debian.org/releases/stable/releasenotes
180 [quote, 'https://www.devuan.org']
182 Devuan GNU+Linux is a fork of Debian without systemd that allows users to
183 reclaim control over their system by avoiding unnecessary entanglements and
184 ensuring Init Freedom.
191 [quote, 'https://getfedora.org']
193 Fedora creates an innovative, free, and open source platform for hardware,
194 clouds, and containers that enables software developers and community members
195 to build tailored solutions for their users.
198 https://fedoraproject.org/wiki/Releases
203 [quote, 'https://www.gentoo.org']
205 a highly flexible, source-based Linux distribution.
211 [quote, 'https://www.opensuse.org']
213 The makers' choice for sysadmins, developers and desktop users.
216 https://get.opensuse.org/leap/
221 [quote, 'https://ubuntu.com/']
223 Ubuntu is the modern, open source operating system on Linux for the enterprise
224 server, desktop, cloud, and IoT.
227 https://wiki.ubuntu.com/Releases
229 [[pct_container_images]]
233 Container images, sometimes also referred to as ``templates'' or
234 ``appliances'', are `tar` archives which contain everything to run a container.
236 {pve} itself provides a variety of basic templates for the
237 xref:pct_supported_distributions[most common Linux distributions]. They can be
238 downloaded using the GUI or the `pveam` (short for {pve} Appliance Manager)
239 command line utility. Additionally, https://www.turnkeylinux.org/[TurnKey
240 Linux] container templates are also available to download.
242 The list of available templates is updated daily through the 'pve-daily-update'
243 timer. You can also trigger an update manually by executing:
249 To view the list of available images run:
255 You can restrict this large list by specifying the `section` you are
256 interested in, for example basic `system` images:
258 .List available system images
260 # pveam available --section system
261 system alpine-3.12-default_20200823_amd64.tar.xz
262 system alpine-3.13-default_20210419_amd64.tar.xz
263 system alpine-3.14-default_20210623_amd64.tar.xz
264 system archlinux-base_20210420-1_amd64.tar.gz
265 system centos-7-default_20190926_amd64.tar.xz
266 system centos-8-default_20201210_amd64.tar.xz
267 system debian-9.0-standard_9.7-1_amd64.tar.gz
268 system debian-10-standard_10.7-1_amd64.tar.gz
269 system devuan-3.0-standard_3.0_amd64.tar.gz
270 system fedora-33-default_20201115_amd64.tar.xz
271 system fedora-34-default_20210427_amd64.tar.xz
272 system gentoo-current-default_20200310_amd64.tar.xz
273 system opensuse-15.2-default_20200824_amd64.tar.xz
274 system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz
275 system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz
276 system ubuntu-20.04-standard_20.04-1_amd64.tar.gz
277 system ubuntu-20.10-standard_20.10-1_amd64.tar.gz
278 system ubuntu-21.04-standard_21.04-1_amd64.tar.gz
281 Before you can use such a template, you need to download them into one of your
282 storages. If you're unsure to which one, you can simply use the `local` named
283 storage for that purpose. For clustered installations, it is preferred to use a
284 shared storage so that all nodes can access those images.
287 # pveam download local debian-10.0-standard_10.0-1_amd64.tar.gz
290 You are now ready to create containers using that image, and you can list all
291 downloaded images on storage `local` with:
295 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz 219.95MB
298 TIP: You can also use the {pve} web interface GUI to download, list and delete
301 `pct` uses them to create a new container, for example:
304 # pct create 999 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
307 The above command shows you the full {pve} volume identifiers. They include the
308 storage name, and most other {pve} commands can use them. For example you can
309 delete that image later with:
312 # pveam remove local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
324 [thumbnail="screenshot/gui-create-ct-general.png"]
326 General settings of a container include
328 * the *Node* : the physical server on which the container will run
329 * the *CT ID*: a unique number in this {pve} installation used to identify your
331 * *Hostname*: the hostname of the container
332 * *Resource Pool*: a logical group of containers and VMs
333 * *Password*: the root password of the container
334 * *SSH Public Key*: a public key for connecting to the root account over SSH
335 * *Unprivileged container*: this option allows to choose at creation time
336 if you want to create a privileged or unprivileged container.
338 Unprivileged Containers
339 ^^^^^^^^^^^^^^^^^^^^^^^
341 Unprivileged containers use a new kernel feature called user namespaces.
342 The root UID 0 inside the container is mapped to an unprivileged user outside
343 the container. This means that most security issues (container escape, resource
344 abuse, etc.) in these containers will affect a random unprivileged user, and
345 would be a generic kernel security bug rather than an LXC issue. The LXC team
346 thinks unprivileged containers are safe by design.
348 This is the default option when creating a new container.
350 NOTE: If the container uses systemd as an init system, please be aware the
351 systemd version running inside the container should be equal to or greater than
355 Privileged Containers
356 ^^^^^^^^^^^^^^^^^^^^^
358 Security in containers is achieved by using mandatory access control 'AppArmor'
359 restrictions, 'seccomp' filters and Linux kernel namespaces. The LXC team
360 considers this kind of container as unsafe, and they will not consider new
361 container escape exploits to be security issues worthy of a CVE and quick fix.
362 That's why privileged containers should only be used in trusted environments.
369 [thumbnail="screenshot/gui-create-ct-cpu.png"]
371 You can restrict the number of visible CPUs inside the container using the
372 `cores` option. This is implemented using the Linux 'cpuset' cgroup
373 (**c**ontrol *group*).
374 A special task inside `pvestatd` tries to distribute running containers among
375 available CPUs periodically.
376 To view the assigned CPUs run the following command:
380 ---------------------
384 ---------------------
387 Containers use the host kernel directly. All tasks inside a container are
388 handled by the host CPU scheduler. {pve} uses the Linux 'CFS' (**C**ompletely
389 **F**air **S**cheduler) scheduler by default, which has additional bandwidth
394 `cpulimit`: :: You can use this option to further limit assigned CPU time.
395 Please note that this is a floating point number, so it is perfectly valid to
396 assign two cores to a container, but restrict overall CPU consumption to half a
404 `cpuunits`: :: This is a relative weight passed to the kernel scheduler. The
405 larger the number is, the more CPU time this container gets. Number is relative
406 to the weights of all the other running containers. The default is 1024. You
407 can use this setting to prioritize some containers.
414 [thumbnail="screenshot/gui-create-ct-memory.png"]
416 Container memory is controlled using the cgroup memory controller.
420 `memory`: :: Limit overall memory usage. This corresponds to the
421 `memory.limit_in_bytes` cgroup setting.
423 `swap`: :: Allows the container to use additional swap memory from the host
424 swap space. This corresponds to the `memory.memsw.limit_in_bytes` cgroup
425 setting, which is set to the sum of both value (`memory + swap`).
432 [thumbnail="screenshot/gui-create-ct-root-disk.png"]
434 The root mount point is configured with the `rootfs` property. You can
435 configure up to 256 additional mount points. The corresponding options are
436 called `mp0` to `mp255`. They can contain the following settings:
438 include::pct-mountpoint-opts.adoc[]
440 Currently there are three types of mount points: storage backed mount points,
441 bind mounts, and device mounts.
443 .Typical container `rootfs` configuration
445 rootfs: thin1:base-100-disk-1,size=8G
449 Storage Backed Mount Points
450 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
452 Storage backed mount points are managed by the {pve} storage subsystem and come
453 in three different flavors:
455 - Image based: these are raw images containing a single ext4 formatted file
457 - ZFS subvolumes: these are technically bind mounts, but with managed storage,
458 and thus allow resizing and snapshotting.
459 - Directories: passing `size=0` triggers a special case where instead of a raw
460 image a directory is created.
462 NOTE: The special option syntax `STORAGE_ID:SIZE_IN_GB` for storage backed
463 mount point volumes will automatically allocate a volume of the specified size
464 on the specified storage. For example, calling
467 pct set 100 -mp0 thin1:10,mp=/path/in/container
470 will allocate a 10GB volume on the storage `thin1` and replace the volume ID
471 place holder `10` with the allocated volume ID, and setup the moutpoint in the
472 container at `/path/in/container`
478 Bind mounts allow you to access arbitrary directories from your Proxmox VE host
479 inside a container. Some potential use cases are:
481 - Accessing your home directory in the guest
482 - Accessing an USB device directory in the guest
483 - Accessing an NFS mount from the host in the guest
485 Bind mounts are considered to not be managed by the storage subsystem, so you
486 cannot make snapshots or deal with quotas from inside the container. With
487 unprivileged containers you might run into permission problems caused by the
488 user mapping and cannot use ACLs.
490 NOTE: The contents of bind mount points are not backed up when using `vzdump`.
492 WARNING: For security reasons, bind mounts should only be established using
493 source directories especially reserved for this purpose, e.g., a directory
494 hierarchy under `/mnt/bindmounts`. Never bind mount system directories like
495 `/`, `/var` or `/etc` into a container - this poses a great security risk.
497 NOTE: The bind mount source path must not contain any symlinks.
499 For example, to make the directory `/mnt/bindmounts/shared` accessible in the
500 container with ID `100` under the path `/shared`, use a configuration line like
501 `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`.
502 Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to
503 achieve the same result.
509 Device mount points allow to mount block devices of the host directly into the
510 container. Similar to bind mounts, device mounts are not managed by {PVE}'s
511 storage subsystem, but the `quota` and `acl` options will be honored.
513 NOTE: Device mount points should only be used under special circumstances. In
514 most cases a storage backed mount point offers the same performance and a lot
517 NOTE: The contents of device mount points are not backed up when using
521 [[pct_container_network]]
525 [thumbnail="screenshot/gui-create-ct-network.png"]
527 You can configure up to 10 network interfaces for a single container.
528 The corresponding options are called `net0` to `net9`, and they can contain the
531 include::pct-network-opts.adoc[]
534 [[pct_startup_and_shutdown]]
535 Automatic Start and Shutdown of Containers
536 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
538 To automatically start a container when the host system boots, select the
539 option 'Start at boot' in the 'Options' panel of the container in the web
540 interface or run the following command:
543 # pct set CTID -onboot 1
546 .Start and Shutdown Order
547 // use the screenshot from qemu - its the same
548 [thumbnail="screenshot/gui-qemu-edit-start-order.png"]
550 If you want to fine tune the boot order of your containers, you can use the
551 following parameters:
553 * *Start/Shutdown order*: Defines the start order priority. For example, set it
554 to 1 if you want the CT to be the first to be started. (We use the reverse
555 startup order for shutdown, so a container with a start order of 1 would be
556 the last to be shut down)
557 * *Startup delay*: Defines the interval between this container start and
558 subsequent containers starts. For example, set it to 240 if you want to wait
559 240 seconds before starting other containers.
560 * *Shutdown timeout*: Defines the duration in seconds {pve} should wait
561 for the container to be offline after issuing a shutdown command.
562 By default this value is set to 60, which means that {pve} will issue a
563 shutdown request, wait 60s for the machine to be offline, and if after 60s
564 the machine is still online will notify that the shutdown action failed.
566 Please note that containers without a Start/Shutdown order parameter will
567 always start after those where the parameter is set, and this parameter only
568 makes sense between the machines running locally on a host, and not
571 If you require a delay between the host boot and the booting of the first
572 container, see the section on
573 xref:first_guest_boot_delay[Proxmox VE Node Management].
579 You can add a hook script to CTs with the config property `hookscript`.
582 # pct set 100 -hookscript local:snippets/hookscript.pl
585 It will be called during various phases of the guests lifetime. For an example
586 and documentation see the example script under
587 `/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
589 Security Considerations
590 -----------------------
592 Containers use the kernel of the host system. This exposes an attack surface
593 for malicious users. In general, full virtual machines provide better
594 isolation. This should be considered if containers are provided to unknown or
597 To reduce the attack surface, LXC uses many security features like AppArmor,
598 CGroups and kernel namespaces.
603 AppArmor profiles are used to restrict access to possibly dangerous actions.
604 Some system calls, i.e. `mount`, are prohibited from execution.
606 To trace AppArmor activity, use:
609 # dmesg | grep apparmor
612 Although it is not recommended, AppArmor can be disabled for a container. This
613 brings security risks with it. Some syscalls can lead to privilege escalation
614 when executed within a container if the system is misconfigured or if a LXC or
615 Linux Kernel vulnerability exists.
617 To disable AppArmor for a container, add the following line to the container
618 configuration file located at `/etc/pve/lxc/CTID.conf`:
621 lxc.apparmor.profile = unconfined
624 WARNING: Please note that this is not recommended for production use.
628 Control Groups ('cgroup')
629 ~~~~~~~~~~~~~~~~~~~~~~~~~
632 mechanism used to hierarchically organize processes and distribute system
635 The main resources controlled via 'cgroups' are CPU time, memory and swap
636 limits, and access to device nodes. 'cgroups' are also used to "freeze" a
637 container before taking snapshots.
639 There are 2 versions of 'cgroups' currently available,
640 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v1/index.html[legacy]
642 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v2.html['cgroupv2'].
644 Since {pve} 7.0, the default is a pure 'cgroupv2' environment. Previously a
645 "hybrid" setup was used, where resource control was mainly done in 'cgroupv1'
646 with an additional 'cgroupv2' controller which could take over some subsystems
647 via the 'cgroup_no_v1' kernel command line parameter. (See the
648 https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html[kernel
649 parameter documentation] for details.)
651 [[pct_cgroup_compat]]
652 CGroup Version Compatibility
653 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
654 The main difference between pure 'cgroupv2' and the old hybrid environments
655 regarding {pve} is that with 'cgroupv2' memory and swap are now controlled
656 independently. The memory and swap settings for containers can map directly to
657 these values, whereas previously only the memory limit and the limit of the
658 *sum* of memory and swap could be limited.
660 Another important difference is that the 'devices' controller is configured in a
661 completely different way. Because of this, file system quotas are currently not
662 supported in a pure 'cgroupv2' environment.
664 'cgroupv2' support by the container's OS is needed to run in a pure 'cgroupv2'
665 environment. Containers running 'systemd' version 231 or newer support
666 'cgroupv2' footnote:[this includes all newest major versions of container
667 templates shipped by {pve}], as do containers not using 'systemd' as init
668 system footnote:[for example Alpine Linux].
672 CentOS 7 and Ubuntu 16.10 are two prominent Linux distributions releases,
673 which have a 'systemd' version that is too old to run in a 'cgroupv2'
674 environment, you can either
676 * Upgrade the whole distribution to a newer release. For the examples above, that
677 could be Ubuntu 18.04 or 20.04, and CentOS 8 (or RHEL/CentOS derivatives like
678 AlmaLinux or Rocky Linux). This has the benefit to get the newest bug and
679 security fixes, often also new features, and moving the EOL date in the future.
681 * Upgrade the Containers systemd version. If the distribution provides a
682 backports repository this can be an easy and quick stop-gap measurement.
684 * Move the container, or its services, to a Virtual Machine. Virtual Machines
685 have a much less interaction with the host, that's why one can install
686 decades old OS versions just fine there.
688 * Switch back to the legacy 'cgroup' controller. Note that while it can be a
689 valid solution, it's not a permanent one. There's a high likelihood that a
690 future {pve} major release, for example 8.0, cannot support the legacy
694 [[pct_cgroup_change_version]]
695 Changing CGroup Version
696 ^^^^^^^^^^^^^^^^^^^^^^^
698 TIP: If file system quotas are not required and all containers support 'cgroupv2',
699 it is recommended to stick to the new default.
701 To switch back to the previous version the following kernel command line
702 parameter can be used:
705 systemd.unified_cgroup_hierarchy=0
708 See xref:sysboot_edit_kernel_cmdline[this section] on editing the kernel boot
709 command line on where to add the parameter.
711 // TODO: seccomp a bit more.
712 // TODO: pve-lxc-syscalld
715 Guest Operating System Configuration
716 ------------------------------------
718 {pve} tries to detect the Linux distribution in the container, and modifies
719 some files. Here is a short list of things done at container startup:
721 set /etc/hostname:: to set the container name
723 modify /etc/hosts:: to allow lookup of the local hostname
725 network setup:: pass the complete network setup to the container
727 configure DNS:: pass information about DNS servers
729 adapt the init system:: for example, fix the number of spawned getty processes
731 set the root password:: when creating a new container
733 rewrite ssh_host_keys:: so that each container has unique keys
735 randomize crontab:: so that cron does not start at the same time on all containers
737 Changes made by {PVE} are enclosed by comment markers:
745 Those markers will be inserted at a reasonable location in the file. If such a
746 section already exists, it will be updated in place and will not be moved.
748 Modification of a file can be prevented by adding a `.pve-ignore.` file for it.
749 For instance, if the file `/etc/.pve-ignore.hosts` exists then the `/etc/hosts`
750 file will not be touched. This can be a simple empty file created via:
753 # touch /etc/.pve-ignore.hosts
756 Most modifications are OS dependent, so they differ between different
757 distributions and versions. You can completely disable modifications by
758 manually setting the `ostype` to `unmanaged`.
760 OS type detection is done by testing for certain files inside the
761 container. {pve} first checks the `/etc/os-release` file
762 footnote:[/etc/os-release replaces the multitude of per-distribution
763 release files https://manpages.debian.org/stable/systemd/os-release.5.en.html].
764 If that file is not present, or it does not contain a clearly recognizable
765 distribution identifier the following distribution specific release files are
768 Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`)
770 Debian:: test /etc/debian_version
772 Fedora:: test /etc/fedora-release
774 RedHat or CentOS:: test /etc/redhat-release
776 ArchLinux:: test /etc/arch-release
778 Alpine:: test /etc/alpine-release
780 Gentoo:: test /etc/gentoo-release
782 NOTE: Container start fails if the configured `ostype` differs from the auto
786 [[pct_container_storage]]
790 The {pve} LXC container storage model is more flexible than traditional
791 container storage models. A container can have multiple mount points. This
792 makes it possible to use the best suited storage for each application.
794 For example the root file system of the container can be on slow and cheap
795 storage while the database can be on fast and distributed storage via a second
796 mount point. See section <<pct_mount_points, Mount Points>> for further
799 Any storage type supported by the {pve} storage library can be used. This means
800 that containers can be stored on local (for example `lvm`, `zfs` or directory),
801 shared external (like `iSCSI`, `NFS`) or even distributed storage systems like
802 Ceph. Advanced storage features like snapshots or clones can be used if the
803 underlying storage supports them. The `vzdump` backup tool can use snapshots to
804 provide consistent container backups.
806 Furthermore, local devices or local directories can be mounted directly using
807 'bind mounts'. This gives access to local resources inside a container with
808 practically zero overhead. Bind mounts can be used as an easy way to share data
815 WARNING: Because of existing issues in the Linux kernel's freezer subsystem the
816 usage of FUSE mounts inside a container is strongly advised against, as
817 containers need to be frozen for suspend or snapshot mode backups.
819 If FUSE mounts cannot be replaced by other mounting mechanisms or storage
820 technologies, it is possible to establish the FUSE mount on the Proxmox host
821 and use a bind mount point to make it accessible inside the container.
824 Using Quotas Inside Containers
825 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
827 Quotas allow to set limits inside a container for the amount of disk space that
830 NOTE: This currently requires the use of legacy 'cgroups'.
832 NOTE: This only works on ext4 image based storage types and currently only
833 works with privileged containers.
835 Activating the `quota` option causes the following mount options to be used for
837 `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0`
839 This allows quotas to be used like on any other system. You can initialize the
840 `/aquota.user` and `/aquota.group` files by running:
847 Then edit the quotas using the `edquota` command. Refer to the documentation of
848 the distribution running inside the container for details.
850 NOTE: You need to run the above commands for every mount point by passing the
851 mount point's path instead of just `/`.
854 Using ACLs Inside Containers
855 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
857 The standard Posix **A**ccess **C**ontrol **L**ists are also available inside
858 containers. ACLs allow you to set more detailed file ownership than the
859 traditional user/group/others model.
862 Backup of Container mount points
863 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
865 To include a mount point in backups, enable the `backup` option for it in the
866 container configuration. For an existing mount point `mp0`
869 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G
872 add `backup=1` to enable it.
875 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G,backup=1
878 NOTE: When creating a new mount point in the GUI, this option is enabled by
881 To disable backups for a mount point, add `backup=0` in the way described
882 above, or uncheck the *Backup* checkbox on the GUI.
884 Replication of Containers mount points
885 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
887 By default, additional mount points are replicated when the Root Disk is
888 replicated. If you want the {pve} storage replication mechanism to skip a mount
889 point, you can set the *Skip replication* option for that mount point.
890 As of {pve} 5.0, replication requires a storage of type `zfspool`. Adding a
891 mount point to a different type of storage when the container has replication
892 configured requires to have *Skip replication* enabled for that mount point.
902 It is possible to use the `vzdump` tool for container backup. Please refer to
903 the `vzdump` manual page for details.
906 Restoring Container Backups
907 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
909 Restoring container backups made with `vzdump` is possible using the `pct
910 restore` command. By default, `pct restore` will attempt to restore as much of
911 the backed up container configuration as possible. It is possible to override
912 the backed up configuration by manually setting container options on the
913 command line (see the `pct` manual page for details).
915 NOTE: `pvesm extractconfig` can be used to view the backed up configuration
916 contained in a vzdump archive.
918 There are two basic restore modes, only differing by their handling of mount
922 ``Simple'' Restore Mode
923 ^^^^^^^^^^^^^^^^^^^^^^^
925 If neither the `rootfs` parameter nor any of the optional `mpX` parameters are
926 explicitly set, the mount point configuration from the backed up configuration
927 file is restored using the following steps:
929 . Extract mount points and their options from backup
930 . Create volumes for storage backed mount points on the storage provided with
931 the `storage` parameter (default: `local`).
932 . Extract files from backup archive
933 . Add bind and device mount points to restored configuration (limited to root
936 NOTE: Since bind and device mount points are never backed up, no files are
937 restored in the last step, but only the configuration options. The assumption
938 is that such mount points are either backed up with another mechanism (e.g.,
939 NFS space that is bind mounted into many containers), or not intended to be
942 This simple mode is also used by the container restore operations in the web
946 ``Advanced'' Restore Mode
947 ^^^^^^^^^^^^^^^^^^^^^^^^^
949 By setting the `rootfs` parameter (and optionally, any combination of `mpX`
950 parameters), the `pct restore` command is automatically switched into an
951 advanced mode. This advanced mode completely ignores the `rootfs` and `mpX`
952 configuration options contained in the backup archive, and instead only uses
953 the options explicitly provided as parameters.
955 This mode allows flexible configuration of mount point settings at restore
958 * Set target storages, volume sizes and other options for each mount point
960 * Redistribute backed up files according to new mount point scheme
961 * Restore to device and/or bind mount points (limited to root user)
964 Managing Containers with `pct`
965 ------------------------------
967 The ``Proxmox Container Toolkit'' (`pct`) is the command line tool to manage
968 {pve} containers. It enables you to create or destroy containers, as well as
969 control the container execution (start, stop, reboot, migrate, etc.). It can be
970 used to set parameters in the config file of a container, for example the
971 network configuration or memory limits.
976 Create a container based on a Debian template (provided you have already
977 downloaded the template via the web interface)
980 # pct create 100 /var/lib/vz/template/cache/debian-10.0-standard_10.0-1_amd64.tar.gz
989 Start a login session via getty
995 Enter the LXC namespace and run a shell as root user
1001 Display the configuration
1007 Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, set
1008 the address and gateway, while it's running
1011 # pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1
1014 Reduce the memory of the container to 512MB
1017 # pct set 100 -memory 512
1020 Destroying a container always removes it from Access Control Lists and it always
1021 removes the firewall configuration of the container. You have to activate
1022 '--purge', if you want to additionally remove the container from replication jobs,
1023 backup jobs and HA resource configurations.
1026 # pct destroy 100 --purge
1031 Obtaining Debugging Logs
1032 ~~~~~~~~~~~~~~~~~~~~~~~~
1034 In case `pct start` is unable to start a specific container, it might be
1035 helpful to collect debugging output by passing the `--debug` flag (replace `CTID` with
1036 the container's CTID):
1039 # pct start CTID --debug
1042 Alternatively, you can use the following `lxc-start` command, which will save
1043 the debug log to the file specified by the `-o` output option:
1046 # lxc-start -n CTID -F -l DEBUG -o /tmp/lxc-CTID.log
1049 This command will attempt to start the container in foreground mode, to stop
1050 the container run `pct shutdown CTID` or `pct stop CTID` in a second terminal.
1052 The collected debug log is written to `/tmp/lxc-CTID.log`.
1054 NOTE: If you have changed the container's configuration since the last start
1055 attempt with `pct start`, you need to run `pct start` at least once to also
1056 update the configuration used by `lxc-start`.
1062 If you have a cluster, you can migrate your Containers with
1065 # pct migrate <ctid> <target>
1068 This works as long as your Container is offline. If it has local volumes or
1069 mount points defined, the migration will copy the content over the network to
1070 the target host if the same storage is defined there.
1072 Running containers cannot live-migrated due to technical limitations. You can
1073 do a restart migration, which shuts down, moves and then starts a container
1074 again on the target node. As containers are very lightweight, this results
1075 normally only in a downtime of some hundreds of milliseconds.
1077 A restart migration can be done through the web interface or by using the
1078 `--restart` flag with the `pct migrate` command.
1080 A restart migration will shut down the Container and kill it after the
1081 specified timeout (the default is 180 seconds). Then it will migrate the
1082 Container like an offline migration and when finished, it starts the Container
1085 [[pct_configuration]]
1089 The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, where
1090 `<CTID>` is the numeric ID of the given container. Like all other files stored
1091 inside `/etc/pve/`, they get automatically replicated to all other cluster
1094 NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be
1095 unique cluster wide.
1097 .Example Container Configuration
1104 net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth
1105 rootfs: local:107/vm-107-disk-1.raw,size=7G
1108 The configuration files are simple text files. You can edit them using a normal
1109 text editor, for example, `vi` or `nano`.
1110 This is sometimes useful to do small corrections, but keep in mind that you
1111 need to restart the container to apply such changes.
1113 For that reason, it is usually better to use the `pct` command to generate and
1114 modify those files, or do the whole thing using the GUI.
1115 Our toolkit is smart enough to instantaneously apply most changes to running
1116 containers. This feature is called ``hot plug'', and there is no need to restart
1117 the container in that case.
1119 In cases where a change cannot be hot-plugged, it will be registered as a
1120 pending change (shown in red color in the GUI).
1121 They will only be applied after rebooting the container.
1127 The container configuration file uses a simple colon separated key/value
1128 format. Each line has the following format:
1135 Blank lines in those files are ignored, and lines starting with a `#` character
1136 are treated as comments and are also ignored.
1138 It is possible to add low-level, LXC style configuration directly, for example:
1141 lxc.init_cmd: /sbin/my_own_init
1147 lxc.init_cmd = /sbin/my_own_init
1150 The settings are passed directly to the LXC low-level tools.
1157 When you create a snapshot, `pct` stores the configuration at snapshot time
1158 into a separate snapshot section within the same configuration file. For
1159 example, after creating a snapshot called ``testsnapshot'', your configuration
1160 file will look like this:
1162 .Container configuration with snapshot
1172 snaptime: 1457170803
1176 There are a few snapshot related properties like `parent` and `snaptime`. The
1177 `parent` property is used to store the parent/child relationship between
1178 snapshots. `snaptime` is the snapshot creation time stamp (Unix epoch).
1185 include::pct.conf.5-opts.adoc[]
1191 Container migrations, snapshots and backups (`vzdump`) set a lock to prevent
1192 incompatible concurrent actions on the affected container. Sometimes you need
1193 to remove such a lock manually (e.g., after a power failure).
1199 CAUTION: Only do this if you are sure the action which set the lock is no
1208 `/etc/pve/lxc/<CTID>.conf`::
1210 Configuration file for the container '<CTID>'.
1213 include::pve-copyright.adoc[]