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 For currently supported releases see: https://alpinelinux.org/releases/
118 [quote, 'https://archlinux.org/']
120 Arch Linux, a lightweight and flexible Linux® distribution that tries to Keep It Simple.
123 Arch Linux is using a rolling-release model, see its wiki for more details:
125 https://wiki.archlinux.org/title/Arch_Linux
127 CentOS, Almalinux, Rocky Linux
128 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
130 CentOS / CentOS Stream
131 ^^^^^^^^^^^^^^^^^^^^^^
133 [quote, 'https://centos.org']
135 The CentOS Linux distribution is a stable, predictable, manageable and
136 reproducible platform derived from the sources of Red Hat Enterprise Linux
140 For currently supported releases see:
142 https://wiki.centos.org/About/Product
147 [quote, 'https://almalinux.org']
149 An Open Source, community owned and governed, forever-free enterprise Linux
150 distribution, focused on long-term stability, providing a robust
151 production-grade platform. AlmaLinux OS is 1:1 binary compatible with RHEL® and
156 For currently supported releases see:
158 https://en.wikipedia.org/wiki/AlmaLinux#Releases
163 [quote, 'https://rockylinux.org']
165 Rocky Linux is a community enterprise operating system designed to be 100%
166 bug-for-bug compatible with America's top enterprise Linux distribution now
167 that its downstream partner has shifted direction.
170 For currently supported releases see:
172 https://en.wikipedia.org/wiki/Rocky_Linux#Releases
177 [quote, 'https://www.debian.org/intro/index#software']
179 Debian is a free operating system, developed and maintained by the Debian
180 project. A free Linux distribution with thousands of applications to meet our
184 For currently supported releases see:
186 https://www.debian.org/releases/stable/releasenotes
191 [quote, 'https://www.devuan.org']
193 Devuan GNU+Linux is a fork of Debian without systemd that allows users to
194 reclaim control over their system by avoiding unnecessary entanglements and
195 ensuring Init Freedom.
198 For currently supported releases see:
200 https://www.devuan.org/os/releases
205 [quote, 'https://getfedora.org']
207 Fedora creates an innovative, free, and open source platform for hardware,
208 clouds, and containers that enables software developers and community members
209 to build tailored solutions for their users.
212 For currently supported releases see:
214 https://fedoraproject.org/wiki/Releases
219 [quote, 'https://www.gentoo.org']
221 a highly flexible, source-based Linux distribution.
224 Gentoo is using a rolling-release model.
229 [quote, 'https://www.opensuse.org']
231 The makers' choice for sysadmins, developers and desktop users.
234 For currently supported releases see:
236 https://get.opensuse.org/leap/
241 [quote, 'https://ubuntu.com/']
243 Ubuntu is the modern, open source operating system on Linux for the enterprise
244 server, desktop, cloud, and IoT.
247 For currently supported releases see:
249 https://wiki.ubuntu.com/Releases
251 [[pct_container_images]]
255 Container images, sometimes also referred to as ``templates'' or
256 ``appliances'', are `tar` archives which contain everything to run a container.
258 {pve} itself provides a variety of basic templates for the
259 xref:pct_supported_distributions[most common Linux distributions]. They can be
260 downloaded using the GUI or the `pveam` (short for {pve} Appliance Manager)
261 command line utility. Additionally, https://www.turnkeylinux.org/[TurnKey
262 Linux] container templates are also available to download.
264 The list of available templates is updated daily through the 'pve-daily-update'
265 timer. You can also trigger an update manually by executing:
271 To view the list of available images run:
277 You can restrict this large list by specifying the `section` you are
278 interested in, for example basic `system` images:
280 .List available system images
282 # pveam available --section system
283 system alpine-3.12-default_20200823_amd64.tar.xz
284 system alpine-3.13-default_20210419_amd64.tar.xz
285 system alpine-3.14-default_20210623_amd64.tar.xz
286 system archlinux-base_20210420-1_amd64.tar.gz
287 system centos-7-default_20190926_amd64.tar.xz
288 system centos-8-default_20201210_amd64.tar.xz
289 system debian-9.0-standard_9.7-1_amd64.tar.gz
290 system debian-10-standard_10.7-1_amd64.tar.gz
291 system devuan-3.0-standard_3.0_amd64.tar.gz
292 system fedora-33-default_20201115_amd64.tar.xz
293 system fedora-34-default_20210427_amd64.tar.xz
294 system gentoo-current-default_20200310_amd64.tar.xz
295 system opensuse-15.2-default_20200824_amd64.tar.xz
296 system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz
297 system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz
298 system ubuntu-20.04-standard_20.04-1_amd64.tar.gz
299 system ubuntu-20.10-standard_20.10-1_amd64.tar.gz
300 system ubuntu-21.04-standard_21.04-1_amd64.tar.gz
303 Before you can use such a template, you need to download them into one of your
304 storages. If you're unsure to which one, you can simply use the `local` named
305 storage for that purpose. For clustered installations, it is preferred to use a
306 shared storage so that all nodes can access those images.
309 # pveam download local debian-10.0-standard_10.0-1_amd64.tar.gz
312 You are now ready to create containers using that image, and you can list all
313 downloaded images on storage `local` with:
317 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz 219.95MB
320 TIP: You can also use the {pve} web interface GUI to download, list and delete
323 `pct` uses them to create a new container, for example:
326 # pct create 999 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
329 The above command shows you the full {pve} volume identifiers. They include the
330 storage name, and most other {pve} commands can use them. For example you can
331 delete that image later with:
334 # pveam remove local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
346 [thumbnail="screenshot/gui-create-ct-general.png"]
348 General settings of a container include
350 * the *Node* : the physical server on which the container will run
351 * the *CT ID*: a unique number in this {pve} installation used to identify your
353 * *Hostname*: the hostname of the container
354 * *Resource Pool*: a logical group of containers and VMs
355 * *Password*: the root password of the container
356 * *SSH Public Key*: a public key for connecting to the root account over SSH
357 * *Unprivileged container*: this option allows to choose at creation time
358 if you want to create a privileged or unprivileged container.
360 Unprivileged Containers
361 ^^^^^^^^^^^^^^^^^^^^^^^
363 Unprivileged containers use a new kernel feature called user namespaces.
364 The root UID 0 inside the container is mapped to an unprivileged user outside
365 the container. This means that most security issues (container escape, resource
366 abuse, etc.) in these containers will affect a random unprivileged user, and
367 would be a generic kernel security bug rather than an LXC issue. The LXC team
368 thinks unprivileged containers are safe by design.
370 This is the default option when creating a new container.
372 NOTE: If the container uses systemd as an init system, please be aware the
373 systemd version running inside the container should be equal to or greater than
377 Privileged Containers
378 ^^^^^^^^^^^^^^^^^^^^^
380 Security in containers is achieved by using mandatory access control 'AppArmor'
381 restrictions, 'seccomp' filters and Linux kernel namespaces. The LXC team
382 considers this kind of container as unsafe, and they will not consider new
383 container escape exploits to be security issues worthy of a CVE and quick fix.
384 That's why privileged containers should only be used in trusted environments.
391 [thumbnail="screenshot/gui-create-ct-cpu.png"]
393 You can restrict the number of visible CPUs inside the container using the
394 `cores` option. This is implemented using the Linux 'cpuset' cgroup
395 (**c**ontrol *group*).
396 A special task inside `pvestatd` tries to distribute running containers among
397 available CPUs periodically.
398 To view the assigned CPUs run the following command:
402 ---------------------
406 ---------------------
409 Containers use the host kernel directly. All tasks inside a container are
410 handled by the host CPU scheduler. {pve} uses the Linux 'CFS' (**C**ompletely
411 **F**air **S**cheduler) scheduler by default, which has additional bandwidth
416 `cpulimit`: :: You can use this option to further limit assigned CPU time.
417 Please note that this is a floating point number, so it is perfectly valid to
418 assign two cores to a container, but restrict overall CPU consumption to half a
426 `cpuunits`: :: This is a relative weight passed to the kernel scheduler. The
427 larger the number is, the more CPU time this container gets. Number is relative
428 to the weights of all the other running containers. The default is 1024. You
429 can use this setting to prioritize some containers.
436 [thumbnail="screenshot/gui-create-ct-memory.png"]
438 Container memory is controlled using the cgroup memory controller.
442 `memory`: :: Limit overall memory usage. This corresponds to the
443 `memory.limit_in_bytes` cgroup setting.
445 `swap`: :: Allows the container to use additional swap memory from the host
446 swap space. This corresponds to the `memory.memsw.limit_in_bytes` cgroup
447 setting, which is set to the sum of both value (`memory + swap`).
454 [thumbnail="screenshot/gui-create-ct-root-disk.png"]
456 The root mount point is configured with the `rootfs` property. You can
457 configure up to 256 additional mount points. The corresponding options are
458 called `mp0` to `mp255`. They can contain the following settings:
460 include::pct-mountpoint-opts.adoc[]
462 Currently there are three types of mount points: storage backed mount points,
463 bind mounts, and device mounts.
465 .Typical container `rootfs` configuration
467 rootfs: thin1:base-100-disk-1,size=8G
471 Storage Backed Mount Points
472 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
474 Storage backed mount points are managed by the {pve} storage subsystem and come
475 in three different flavors:
477 - Image based: these are raw images containing a single ext4 formatted file
479 - ZFS subvolumes: these are technically bind mounts, but with managed storage,
480 and thus allow resizing and snapshotting.
481 - Directories: passing `size=0` triggers a special case where instead of a raw
482 image a directory is created.
484 NOTE: The special option syntax `STORAGE_ID:SIZE_IN_GB` for storage backed
485 mount point volumes will automatically allocate a volume of the specified size
486 on the specified storage. For example, calling
489 pct set 100 -mp0 thin1:10,mp=/path/in/container
492 will allocate a 10GB volume on the storage `thin1` and replace the volume ID
493 place holder `10` with the allocated volume ID, and setup the moutpoint in the
494 container at `/path/in/container`
500 Bind mounts allow you to access arbitrary directories from your Proxmox VE host
501 inside a container. Some potential use cases are:
503 - Accessing your home directory in the guest
504 - Accessing an USB device directory in the guest
505 - Accessing an NFS mount from the host in the guest
507 Bind mounts are considered to not be managed by the storage subsystem, so you
508 cannot make snapshots or deal with quotas from inside the container. With
509 unprivileged containers you might run into permission problems caused by the
510 user mapping and cannot use ACLs.
512 NOTE: The contents of bind mount points are not backed up when using `vzdump`.
514 WARNING: For security reasons, bind mounts should only be established using
515 source directories especially reserved for this purpose, e.g., a directory
516 hierarchy under `/mnt/bindmounts`. Never bind mount system directories like
517 `/`, `/var` or `/etc` into a container - this poses a great security risk.
519 NOTE: The bind mount source path must not contain any symlinks.
521 For example, to make the directory `/mnt/bindmounts/shared` accessible in the
522 container with ID `100` under the path `/shared`, use a configuration line like
523 `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`.
524 Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to
525 achieve the same result.
531 Device mount points allow to mount block devices of the host directly into the
532 container. Similar to bind mounts, device mounts are not managed by {PVE}'s
533 storage subsystem, but the `quota` and `acl` options will be honored.
535 NOTE: Device mount points should only be used under special circumstances. In
536 most cases a storage backed mount point offers the same performance and a lot
539 NOTE: The contents of device mount points are not backed up when using
543 [[pct_container_network]]
547 [thumbnail="screenshot/gui-create-ct-network.png"]
549 You can configure up to 10 network interfaces for a single container.
550 The corresponding options are called `net0` to `net9`, and they can contain the
553 include::pct-network-opts.adoc[]
556 [[pct_startup_and_shutdown]]
557 Automatic Start and Shutdown of Containers
558 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
560 To automatically start a container when the host system boots, select the
561 option 'Start at boot' in the 'Options' panel of the container in the web
562 interface or run the following command:
565 # pct set CTID -onboot 1
568 .Start and Shutdown Order
569 // use the screenshot from qemu - its the same
570 [thumbnail="screenshot/gui-qemu-edit-start-order.png"]
572 If you want to fine tune the boot order of your containers, you can use the
573 following parameters:
575 * *Start/Shutdown order*: Defines the start order priority. For example, set it
576 to 1 if you want the CT to be the first to be started. (We use the reverse
577 startup order for shutdown, so a container with a start order of 1 would be
578 the last to be shut down)
579 * *Startup delay*: Defines the interval between this container start and
580 subsequent containers starts. For example, set it to 240 if you want to wait
581 240 seconds before starting other containers.
582 * *Shutdown timeout*: Defines the duration in seconds {pve} should wait
583 for the container to be offline after issuing a shutdown command.
584 By default this value is set to 60, which means that {pve} will issue a
585 shutdown request, wait 60s for the machine to be offline, and if after 60s
586 the machine is still online will notify that the shutdown action failed.
588 Please note that containers without a Start/Shutdown order parameter will
589 always start after those where the parameter is set, and this parameter only
590 makes sense between the machines running locally on a host, and not
593 If you require a delay between the host boot and the booting of the first
594 container, see the section on
595 xref:first_guest_boot_delay[Proxmox VE Node Management].
601 You can add a hook script to CTs with the config property `hookscript`.
604 # pct set 100 -hookscript local:snippets/hookscript.pl
607 It will be called during various phases of the guests lifetime. For an example
608 and documentation see the example script under
609 `/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
611 Security Considerations
612 -----------------------
614 Containers use the kernel of the host system. This exposes an attack surface
615 for malicious users. In general, full virtual machines provide better
616 isolation. This should be considered if containers are provided to unknown or
619 To reduce the attack surface, LXC uses many security features like AppArmor,
620 CGroups and kernel namespaces.
625 AppArmor profiles are used to restrict access to possibly dangerous actions.
626 Some system calls, i.e. `mount`, are prohibited from execution.
628 To trace AppArmor activity, use:
631 # dmesg | grep apparmor
634 Although it is not recommended, AppArmor can be disabled for a container. This
635 brings security risks with it. Some syscalls can lead to privilege escalation
636 when executed within a container if the system is misconfigured or if a LXC or
637 Linux Kernel vulnerability exists.
639 To disable AppArmor for a container, add the following line to the container
640 configuration file located at `/etc/pve/lxc/CTID.conf`:
643 lxc.apparmor.profile = unconfined
646 WARNING: Please note that this is not recommended for production use.
650 Control Groups ('cgroup')
651 ~~~~~~~~~~~~~~~~~~~~~~~~~
654 mechanism used to hierarchically organize processes and distribute system
657 The main resources controlled via 'cgroups' are CPU time, memory and swap
658 limits, and access to device nodes. 'cgroups' are also used to "freeze" a
659 container before taking snapshots.
661 There are 2 versions of 'cgroups' currently available,
662 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v1/index.html[legacy]
664 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v2.html['cgroupv2'].
666 Since {pve} 7.0, the default is a pure 'cgroupv2' environment. Previously a
667 "hybrid" setup was used, where resource control was mainly done in 'cgroupv1'
668 with an additional 'cgroupv2' controller which could take over some subsystems
669 via the 'cgroup_no_v1' kernel command line parameter. (See the
670 https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html[kernel
671 parameter documentation] for details.)
673 [[pct_cgroup_compat]]
674 CGroup Version Compatibility
675 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
676 The main difference between pure 'cgroupv2' and the old hybrid environments
677 regarding {pve} is that with 'cgroupv2' memory and swap are now controlled
678 independently. The memory and swap settings for containers can map directly to
679 these values, whereas previously only the memory limit and the limit of the
680 *sum* of memory and swap could be limited.
682 Another important difference is that the 'devices' controller is configured in a
683 completely different way. Because of this, file system quotas are currently not
684 supported in a pure 'cgroupv2' environment.
686 'cgroupv2' support by the container's OS is needed to run in a pure 'cgroupv2'
687 environment. Containers running 'systemd' version 231 or newer support
688 'cgroupv2' footnote:[this includes all newest major versions of container
689 templates shipped by {pve}], as do containers not using 'systemd' as init
690 system footnote:[for example Alpine Linux].
694 CentOS 7 and Ubuntu 16.10 are two prominent Linux distributions releases,
695 which have a 'systemd' version that is too old to run in a 'cgroupv2'
696 environment, you can either
698 * Upgrade the whole distribution to a newer release. For the examples above, that
699 could be Ubuntu 18.04 or 20.04, and CentOS 8 (or RHEL/CentOS derivatives like
700 AlmaLinux or Rocky Linux). This has the benefit to get the newest bug and
701 security fixes, often also new features, and moving the EOL date in the future.
703 * Upgrade the Containers systemd version. If the distribution provides a
704 backports repository this can be an easy and quick stop-gap measurement.
706 * Move the container, or its services, to a Virtual Machine. Virtual Machines
707 have a much less interaction with the host, that's why one can install
708 decades old OS versions just fine there.
710 * Switch back to the legacy 'cgroup' controller. Note that while it can be a
711 valid solution, it's not a permanent one. There's a high likelihood that a
712 future {pve} major release, for example 8.0, cannot support the legacy
716 [[pct_cgroup_change_version]]
717 Changing CGroup Version
718 ^^^^^^^^^^^^^^^^^^^^^^^
720 TIP: If file system quotas are not required and all containers support 'cgroupv2',
721 it is recommended to stick to the new default.
723 To switch back to the previous version the following kernel command line
724 parameter can be used:
727 systemd.unified_cgroup_hierarchy=0
730 See xref:sysboot_edit_kernel_cmdline[this section] on editing the kernel boot
731 command line on where to add the parameter.
733 // TODO: seccomp a bit more.
734 // TODO: pve-lxc-syscalld
737 Guest Operating System Configuration
738 ------------------------------------
740 {pve} tries to detect the Linux distribution in the container, and modifies
741 some files. Here is a short list of things done at container startup:
743 set /etc/hostname:: to set the container name
745 modify /etc/hosts:: to allow lookup of the local hostname
747 network setup:: pass the complete network setup to the container
749 configure DNS:: pass information about DNS servers
751 adapt the init system:: for example, fix the number of spawned getty processes
753 set the root password:: when creating a new container
755 rewrite ssh_host_keys:: so that each container has unique keys
757 randomize crontab:: so that cron does not start at the same time on all containers
759 Changes made by {PVE} are enclosed by comment markers:
767 Those markers will be inserted at a reasonable location in the file. If such a
768 section already exists, it will be updated in place and will not be moved.
770 Modification of a file can be prevented by adding a `.pve-ignore.` file for it.
771 For instance, if the file `/etc/.pve-ignore.hosts` exists then the `/etc/hosts`
772 file will not be touched. This can be a simple empty file created via:
775 # touch /etc/.pve-ignore.hosts
778 Most modifications are OS dependent, so they differ between different
779 distributions and versions. You can completely disable modifications by
780 manually setting the `ostype` to `unmanaged`.
782 OS type detection is done by testing for certain files inside the
783 container. {pve} first checks the `/etc/os-release` file
784 footnote:[/etc/os-release replaces the multitude of per-distribution
785 release files https://manpages.debian.org/stable/systemd/os-release.5.en.html].
786 If that file is not present, or it does not contain a clearly recognizable
787 distribution identifier the following distribution specific release files are
790 Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`)
792 Debian:: test /etc/debian_version
794 Fedora:: test /etc/fedora-release
796 RedHat or CentOS:: test /etc/redhat-release
798 ArchLinux:: test /etc/arch-release
800 Alpine:: test /etc/alpine-release
802 Gentoo:: test /etc/gentoo-release
804 NOTE: Container start fails if the configured `ostype` differs from the auto
808 [[pct_container_storage]]
812 The {pve} LXC container storage model is more flexible than traditional
813 container storage models. A container can have multiple mount points. This
814 makes it possible to use the best suited storage for each application.
816 For example the root file system of the container can be on slow and cheap
817 storage while the database can be on fast and distributed storage via a second
818 mount point. See section <<pct_mount_points, Mount Points>> for further
821 Any storage type supported by the {pve} storage library can be used. This means
822 that containers can be stored on local (for example `lvm`, `zfs` or directory),
823 shared external (like `iSCSI`, `NFS`) or even distributed storage systems like
824 Ceph. Advanced storage features like snapshots or clones can be used if the
825 underlying storage supports them. The `vzdump` backup tool can use snapshots to
826 provide consistent container backups.
828 Furthermore, local devices or local directories can be mounted directly using
829 'bind mounts'. This gives access to local resources inside a container with
830 practically zero overhead. Bind mounts can be used as an easy way to share data
837 WARNING: Because of existing issues in the Linux kernel's freezer subsystem the
838 usage of FUSE mounts inside a container is strongly advised against, as
839 containers need to be frozen for suspend or snapshot mode backups.
841 If FUSE mounts cannot be replaced by other mounting mechanisms or storage
842 technologies, it is possible to establish the FUSE mount on the Proxmox host
843 and use a bind mount point to make it accessible inside the container.
846 Using Quotas Inside Containers
847 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
849 Quotas allow to set limits inside a container for the amount of disk space that
852 NOTE: This currently requires the use of legacy 'cgroups'.
854 NOTE: This only works on ext4 image based storage types and currently only
855 works with privileged containers.
857 Activating the `quota` option causes the following mount options to be used for
859 `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0`
861 This allows quotas to be used like on any other system. You can initialize the
862 `/aquota.user` and `/aquota.group` files by running:
869 Then edit the quotas using the `edquota` command. Refer to the documentation of
870 the distribution running inside the container for details.
872 NOTE: You need to run the above commands for every mount point by passing the
873 mount point's path instead of just `/`.
876 Using ACLs Inside Containers
877 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
879 The standard Posix **A**ccess **C**ontrol **L**ists are also available inside
880 containers. ACLs allow you to set more detailed file ownership than the
881 traditional user/group/others model.
884 Backup of Container mount points
885 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
887 To include a mount point in backups, enable the `backup` option for it in the
888 container configuration. For an existing mount point `mp0`
891 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G
894 add `backup=1` to enable it.
897 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G,backup=1
900 NOTE: When creating a new mount point in the GUI, this option is enabled by
903 To disable backups for a mount point, add `backup=0` in the way described
904 above, or uncheck the *Backup* checkbox on the GUI.
906 Replication of Containers mount points
907 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
909 By default, additional mount points are replicated when the Root Disk is
910 replicated. If you want the {pve} storage replication mechanism to skip a mount
911 point, you can set the *Skip replication* option for that mount point.
912 As of {pve} 5.0, replication requires a storage of type `zfspool`. Adding a
913 mount point to a different type of storage when the container has replication
914 configured requires to have *Skip replication* enabled for that mount point.
924 It is possible to use the `vzdump` tool for container backup. Please refer to
925 the `vzdump` manual page for details.
928 Restoring Container Backups
929 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
931 Restoring container backups made with `vzdump` is possible using the `pct
932 restore` command. By default, `pct restore` will attempt to restore as much of
933 the backed up container configuration as possible. It is possible to override
934 the backed up configuration by manually setting container options on the
935 command line (see the `pct` manual page for details).
937 NOTE: `pvesm extractconfig` can be used to view the backed up configuration
938 contained in a vzdump archive.
940 There are two basic restore modes, only differing by their handling of mount
944 ``Simple'' Restore Mode
945 ^^^^^^^^^^^^^^^^^^^^^^^
947 If neither the `rootfs` parameter nor any of the optional `mpX` parameters are
948 explicitly set, the mount point configuration from the backed up configuration
949 file is restored using the following steps:
951 . Extract mount points and their options from backup
952 . Create volumes for storage backed mount points on the storage provided with
953 the `storage` parameter (default: `local`).
954 . Extract files from backup archive
955 . Add bind and device mount points to restored configuration (limited to root
958 NOTE: Since bind and device mount points are never backed up, no files are
959 restored in the last step, but only the configuration options. The assumption
960 is that such mount points are either backed up with another mechanism (e.g.,
961 NFS space that is bind mounted into many containers), or not intended to be
964 This simple mode is also used by the container restore operations in the web
968 ``Advanced'' Restore Mode
969 ^^^^^^^^^^^^^^^^^^^^^^^^^
971 By setting the `rootfs` parameter (and optionally, any combination of `mpX`
972 parameters), the `pct restore` command is automatically switched into an
973 advanced mode. This advanced mode completely ignores the `rootfs` and `mpX`
974 configuration options contained in the backup archive, and instead only uses
975 the options explicitly provided as parameters.
977 This mode allows flexible configuration of mount point settings at restore
980 * Set target storages, volume sizes and other options for each mount point
982 * Redistribute backed up files according to new mount point scheme
983 * Restore to device and/or bind mount points (limited to root user)
986 Managing Containers with `pct`
987 ------------------------------
989 The ``Proxmox Container Toolkit'' (`pct`) is the command line tool to manage
990 {pve} containers. It enables you to create or destroy containers, as well as
991 control the container execution (start, stop, reboot, migrate, etc.). It can be
992 used to set parameters in the config file of a container, for example the
993 network configuration or memory limits.
998 Create a container based on a Debian template (provided you have already
999 downloaded the template via the web interface)
1002 # pct create 100 /var/lib/vz/template/cache/debian-10.0-standard_10.0-1_amd64.tar.gz
1011 Start a login session via getty
1017 Enter the LXC namespace and run a shell as root user
1023 Display the configuration
1029 Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, set
1030 the address and gateway, while it's running
1033 # pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1
1036 Reduce the memory of the container to 512MB
1039 # pct set 100 -memory 512
1042 Destroying a container always removes it from Access Control Lists and it always
1043 removes the firewall configuration of the container. You have to activate
1044 '--purge', if you want to additionally remove the container from replication jobs,
1045 backup jobs and HA resource configurations.
1048 # pct destroy 100 --purge
1053 Obtaining Debugging Logs
1054 ~~~~~~~~~~~~~~~~~~~~~~~~
1056 In case `pct start` is unable to start a specific container, it might be
1057 helpful to collect debugging output by passing the `--debug` flag (replace `CTID` with
1058 the container's CTID):
1061 # pct start CTID --debug
1064 Alternatively, you can use the following `lxc-start` command, which will save
1065 the debug log to the file specified by the `-o` output option:
1068 # lxc-start -n CTID -F -l DEBUG -o /tmp/lxc-CTID.log
1071 This command will attempt to start the container in foreground mode, to stop
1072 the container run `pct shutdown CTID` or `pct stop CTID` in a second terminal.
1074 The collected debug log is written to `/tmp/lxc-CTID.log`.
1076 NOTE: If you have changed the container's configuration since the last start
1077 attempt with `pct start`, you need to run `pct start` at least once to also
1078 update the configuration used by `lxc-start`.
1084 If you have a cluster, you can migrate your Containers with
1087 # pct migrate <ctid> <target>
1090 This works as long as your Container is offline. If it has local volumes or
1091 mount points defined, the migration will copy the content over the network to
1092 the target host if the same storage is defined there.
1094 Running containers cannot live-migrated due to technical limitations. You can
1095 do a restart migration, which shuts down, moves and then starts a container
1096 again on the target node. As containers are very lightweight, this results
1097 normally only in a downtime of some hundreds of milliseconds.
1099 A restart migration can be done through the web interface or by using the
1100 `--restart` flag with the `pct migrate` command.
1102 A restart migration will shut down the Container and kill it after the
1103 specified timeout (the default is 180 seconds). Then it will migrate the
1104 Container like an offline migration and when finished, it starts the Container
1107 [[pct_configuration]]
1111 The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, where
1112 `<CTID>` is the numeric ID of the given container. Like all other files stored
1113 inside `/etc/pve/`, they get automatically replicated to all other cluster
1116 NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be
1117 unique cluster wide.
1119 .Example Container Configuration
1126 net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth
1127 rootfs: local:107/vm-107-disk-1.raw,size=7G
1130 The configuration files are simple text files. You can edit them using a normal
1131 text editor, for example, `vi` or `nano`.
1132 This is sometimes useful to do small corrections, but keep in mind that you
1133 need to restart the container to apply such changes.
1135 For that reason, it is usually better to use the `pct` command to generate and
1136 modify those files, or do the whole thing using the GUI.
1137 Our toolkit is smart enough to instantaneously apply most changes to running
1138 containers. This feature is called ``hot plug'', and there is no need to restart
1139 the container in that case.
1141 In cases where a change cannot be hot-plugged, it will be registered as a
1142 pending change (shown in red color in the GUI).
1143 They will only be applied after rebooting the container.
1149 The container configuration file uses a simple colon separated key/value
1150 format. Each line has the following format:
1157 Blank lines in those files are ignored, and lines starting with a `#` character
1158 are treated as comments and are also ignored.
1160 It is possible to add low-level, LXC style configuration directly, for example:
1163 lxc.init_cmd: /sbin/my_own_init
1169 lxc.init_cmd = /sbin/my_own_init
1172 The settings are passed directly to the LXC low-level tools.
1179 When you create a snapshot, `pct` stores the configuration at snapshot time
1180 into a separate snapshot section within the same configuration file. For
1181 example, after creating a snapshot called ``testsnapshot'', your configuration
1182 file will look like this:
1184 .Container configuration with snapshot
1194 snaptime: 1457170803
1198 There are a few snapshot related properties like `parent` and `snaptime`. The
1199 `parent` property is used to store the parent/child relationship between
1200 snapshots. `snaptime` is the snapshot creation time stamp (Unix epoch).
1207 include::pct.conf.5-opts.adoc[]
1213 Container migrations, snapshots and backups (`vzdump`) set a lock to prevent
1214 incompatible concurrent actions on the affected container. Sometimes you need
1215 to remove such a lock manually (e.g., after a power failure).
1221 CAUTION: Only do this if you are sure the action which set the lock is no
1230 `/etc/pve/lxc/<CTID>.conf`::
1232 Configuration file for the container '<CTID>'.
1235 include::pve-copyright.adoc[]