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:
115 https://alpinelinux.org/releases/
120 [quote, 'https://archlinux.org/']
122 Arch Linux, a lightweight and flexible Linux® distribution that tries to Keep It Simple.
125 Arch Linux is using a rolling-release model, see its wiki for more details:
127 https://wiki.archlinux.org/title/Arch_Linux
129 CentOS, Almalinux, Rocky Linux
130 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
132 CentOS / CentOS Stream
133 ^^^^^^^^^^^^^^^^^^^^^^
135 [quote, 'https://centos.org']
137 The CentOS Linux distribution is a stable, predictable, manageable and
138 reproducible platform derived from the sources of Red Hat Enterprise Linux
142 For currently supported releases see:
144 https://wiki.centos.org/About/Product
149 [quote, 'https://almalinux.org']
151 An Open Source, community owned and governed, forever-free enterprise Linux
152 distribution, focused on long-term stability, providing a robust
153 production-grade platform. AlmaLinux OS is 1:1 binary compatible with RHEL® and
158 For currently supported releases see:
160 https://en.wikipedia.org/wiki/AlmaLinux#Releases
165 [quote, 'https://rockylinux.org']
167 Rocky Linux is a community enterprise operating system designed to be 100%
168 bug-for-bug compatible with America's top enterprise Linux distribution now
169 that its downstream partner has shifted direction.
172 For currently supported releases see:
174 https://en.wikipedia.org/wiki/Rocky_Linux#Releases
179 [quote, 'https://www.debian.org/intro/index#software']
181 Debian is a free operating system, developed and maintained by the Debian
182 project. A free Linux distribution with thousands of applications to meet our
186 For currently supported releases see:
188 https://www.debian.org/releases/stable/releasenotes
193 [quote, 'https://www.devuan.org']
195 Devuan GNU+Linux is a fork of Debian without systemd that allows users to
196 reclaim control over their system by avoiding unnecessary entanglements and
197 ensuring Init Freedom.
200 For currently supported releases see:
202 https://www.devuan.org/os/releases
207 [quote, 'https://getfedora.org']
209 Fedora creates an innovative, free, and open source platform for hardware,
210 clouds, and containers that enables software developers and community members
211 to build tailored solutions for their users.
214 For currently supported releases see:
216 https://fedoraproject.org/wiki/Releases
221 [quote, 'https://www.gentoo.org']
223 a highly flexible, source-based Linux distribution.
226 Gentoo is using a rolling-release model.
231 [quote, 'https://www.opensuse.org']
233 The makers' choice for sysadmins, developers and desktop users.
236 For currently supported releases see:
238 https://get.opensuse.org/leap/
243 [quote, 'https://ubuntu.com/']
245 Ubuntu is the modern, open source operating system on Linux for the enterprise
246 server, desktop, cloud, and IoT.
249 For currently supported releases see:
251 https://wiki.ubuntu.com/Releases
253 [[pct_container_images]]
257 Container images, sometimes also referred to as ``templates'' or
258 ``appliances'', are `tar` archives which contain everything to run a container.
260 {pve} itself provides a variety of basic templates for the
261 xref:pct_supported_distributions[most common Linux distributions]. They can be
262 downloaded using the GUI or the `pveam` (short for {pve} Appliance Manager)
263 command line utility. Additionally, https://www.turnkeylinux.org/[TurnKey
264 Linux] container templates are also available to download.
266 The list of available templates is updated daily through the 'pve-daily-update'
267 timer. You can also trigger an update manually by executing:
273 To view the list of available images run:
279 You can restrict this large list by specifying the `section` you are
280 interested in, for example basic `system` images:
282 .List available system images
284 # pveam available --section system
285 system alpine-3.12-default_20200823_amd64.tar.xz
286 system alpine-3.13-default_20210419_amd64.tar.xz
287 system alpine-3.14-default_20210623_amd64.tar.xz
288 system archlinux-base_20210420-1_amd64.tar.gz
289 system centos-7-default_20190926_amd64.tar.xz
290 system centos-8-default_20201210_amd64.tar.xz
291 system debian-9.0-standard_9.7-1_amd64.tar.gz
292 system debian-10-standard_10.7-1_amd64.tar.gz
293 system devuan-3.0-standard_3.0_amd64.tar.gz
294 system fedora-33-default_20201115_amd64.tar.xz
295 system fedora-34-default_20210427_amd64.tar.xz
296 system gentoo-current-default_20200310_amd64.tar.xz
297 system opensuse-15.2-default_20200824_amd64.tar.xz
298 system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz
299 system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz
300 system ubuntu-20.04-standard_20.04-1_amd64.tar.gz
301 system ubuntu-20.10-standard_20.10-1_amd64.tar.gz
302 system ubuntu-21.04-standard_21.04-1_amd64.tar.gz
305 Before you can use such a template, you need to download them into one of your
306 storages. If you're unsure to which one, you can simply use the `local` named
307 storage for that purpose. For clustered installations, it is preferred to use a
308 shared storage so that all nodes can access those images.
311 # pveam download local debian-10.0-standard_10.0-1_amd64.tar.gz
314 You are now ready to create containers using that image, and you can list all
315 downloaded images on storage `local` with:
319 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz 219.95MB
322 TIP: You can also use the {pve} web interface GUI to download, list and delete
325 `pct` uses them to create a new container, for example:
328 # pct create 999 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
331 The above command shows you the full {pve} volume identifiers. They include the
332 storage name, and most other {pve} commands can use them. For example you can
333 delete that image later with:
336 # pveam remove local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
348 [thumbnail="screenshot/gui-create-ct-general.png"]
350 General settings of a container include
352 * the *Node* : the physical server on which the container will run
353 * the *CT ID*: a unique number in this {pve} installation used to identify your
355 * *Hostname*: the hostname of the container
356 * *Resource Pool*: a logical group of containers and VMs
357 * *Password*: the root password of the container
358 * *SSH Public Key*: a public key for connecting to the root account over SSH
359 * *Unprivileged container*: this option allows to choose at creation time
360 if you want to create a privileged or unprivileged container.
362 Unprivileged Containers
363 ^^^^^^^^^^^^^^^^^^^^^^^
365 Unprivileged containers use a new kernel feature called user namespaces.
366 The root UID 0 inside the container is mapped to an unprivileged user outside
367 the container. This means that most security issues (container escape, resource
368 abuse, etc.) in these containers will affect a random unprivileged user, and
369 would be a generic kernel security bug rather than an LXC issue. The LXC team
370 thinks unprivileged containers are safe by design.
372 This is the default option when creating a new container.
374 NOTE: If the container uses systemd as an init system, please be aware the
375 systemd version running inside the container should be equal to or greater than
379 Privileged Containers
380 ^^^^^^^^^^^^^^^^^^^^^
382 Security in containers is achieved by using mandatory access control 'AppArmor'
383 restrictions, 'seccomp' filters and Linux kernel namespaces. The LXC team
384 considers this kind of container as unsafe, and they will not consider new
385 container escape exploits to be security issues worthy of a CVE and quick fix.
386 That's why privileged containers should only be used in trusted environments.
393 [thumbnail="screenshot/gui-create-ct-cpu.png"]
395 You can restrict the number of visible CPUs inside the container using the
396 `cores` option. This is implemented using the Linux 'cpuset' cgroup
397 (**c**ontrol *group*).
398 A special task inside `pvestatd` tries to distribute running containers among
399 available CPUs periodically.
400 To view the assigned CPUs run the following command:
404 ---------------------
408 ---------------------
411 Containers use the host kernel directly. All tasks inside a container are
412 handled by the host CPU scheduler. {pve} uses the Linux 'CFS' (**C**ompletely
413 **F**air **S**cheduler) scheduler by default, which has additional bandwidth
418 `cpulimit`: :: You can use this option to further limit assigned CPU time.
419 Please note that this is a floating point number, so it is perfectly valid to
420 assign two cores to a container, but restrict overall CPU consumption to half a
428 `cpuunits`: :: This is a relative weight passed to the kernel scheduler. The
429 larger the number is, the more CPU time this container gets. Number is relative
430 to the weights of all the other running containers. The default is 1024. You
431 can use this setting to prioritize some containers.
438 [thumbnail="screenshot/gui-create-ct-memory.png"]
440 Container memory is controlled using the cgroup memory controller.
444 `memory`: :: Limit overall memory usage. This corresponds to the
445 `memory.limit_in_bytes` cgroup setting.
447 `swap`: :: Allows the container to use additional swap memory from the host
448 swap space. This corresponds to the `memory.memsw.limit_in_bytes` cgroup
449 setting, which is set to the sum of both value (`memory + swap`).
456 [thumbnail="screenshot/gui-create-ct-root-disk.png"]
458 The root mount point is configured with the `rootfs` property. You can
459 configure up to 256 additional mount points. The corresponding options are
460 called `mp0` to `mp255`. They can contain the following settings:
462 include::pct-mountpoint-opts.adoc[]
464 Currently there are three types of mount points: storage backed mount points,
465 bind mounts, and device mounts.
467 .Typical container `rootfs` configuration
469 rootfs: thin1:base-100-disk-1,size=8G
473 Storage Backed Mount Points
474 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
476 Storage backed mount points are managed by the {pve} storage subsystem and come
477 in three different flavors:
479 - Image based: these are raw images containing a single ext4 formatted file
481 - ZFS subvolumes: these are technically bind mounts, but with managed storage,
482 and thus allow resizing and snapshotting.
483 - Directories: passing `size=0` triggers a special case where instead of a raw
484 image a directory is created.
486 NOTE: The special option syntax `STORAGE_ID:SIZE_IN_GB` for storage backed
487 mount point volumes will automatically allocate a volume of the specified size
488 on the specified storage. For example, calling
491 pct set 100 -mp0 thin1:10,mp=/path/in/container
494 will allocate a 10GB volume on the storage `thin1` and replace the volume ID
495 place holder `10` with the allocated volume ID, and setup the moutpoint in the
496 container at `/path/in/container`
502 Bind mounts allow you to access arbitrary directories from your Proxmox VE host
503 inside a container. Some potential use cases are:
505 - Accessing your home directory in the guest
506 - Accessing an USB device directory in the guest
507 - Accessing an NFS mount from the host in the guest
509 Bind mounts are considered to not be managed by the storage subsystem, so you
510 cannot make snapshots or deal with quotas from inside the container. With
511 unprivileged containers you might run into permission problems caused by the
512 user mapping and cannot use ACLs.
514 NOTE: The contents of bind mount points are not backed up when using `vzdump`.
516 WARNING: For security reasons, bind mounts should only be established using
517 source directories especially reserved for this purpose, e.g., a directory
518 hierarchy under `/mnt/bindmounts`. Never bind mount system directories like
519 `/`, `/var` or `/etc` into a container - this poses a great security risk.
521 NOTE: The bind mount source path must not contain any symlinks.
523 For example, to make the directory `/mnt/bindmounts/shared` accessible in the
524 container with ID `100` under the path `/shared`, use a configuration line like
525 `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`.
526 Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to
527 achieve the same result.
533 Device mount points allow to mount block devices of the host directly into the
534 container. Similar to bind mounts, device mounts are not managed by {PVE}'s
535 storage subsystem, but the `quota` and `acl` options will be honored.
537 NOTE: Device mount points should only be used under special circumstances. In
538 most cases a storage backed mount point offers the same performance and a lot
541 NOTE: The contents of device mount points are not backed up when using
545 [[pct_container_network]]
549 [thumbnail="screenshot/gui-create-ct-network.png"]
551 You can configure up to 10 network interfaces for a single container.
552 The corresponding options are called `net0` to `net9`, and they can contain the
555 include::pct-network-opts.adoc[]
558 [[pct_startup_and_shutdown]]
559 Automatic Start and Shutdown of Containers
560 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
562 To automatically start a container when the host system boots, select the
563 option 'Start at boot' in the 'Options' panel of the container in the web
564 interface or run the following command:
567 # pct set CTID -onboot 1
570 .Start and Shutdown Order
571 // use the screenshot from qemu - its the same
572 [thumbnail="screenshot/gui-qemu-edit-start-order.png"]
574 If you want to fine tune the boot order of your containers, you can use the
575 following parameters:
577 * *Start/Shutdown order*: Defines the start order priority. For example, set it
578 to 1 if you want the CT to be the first to be started. (We use the reverse
579 startup order for shutdown, so a container with a start order of 1 would be
580 the last to be shut down)
581 * *Startup delay*: Defines the interval between this container start and
582 subsequent containers starts. For example, set it to 240 if you want to wait
583 240 seconds before starting other containers.
584 * *Shutdown timeout*: Defines the duration in seconds {pve} should wait
585 for the container to be offline after issuing a shutdown command.
586 By default this value is set to 60, which means that {pve} will issue a
587 shutdown request, wait 60s for the machine to be offline, and if after 60s
588 the machine is still online will notify that the shutdown action failed.
590 Please note that containers without a Start/Shutdown order parameter will
591 always start after those where the parameter is set, and this parameter only
592 makes sense between the machines running locally on a host, and not
595 If you require a delay between the host boot and the booting of the first
596 container, see the section on
597 xref:first_guest_boot_delay[Proxmox VE Node Management].
603 You can add a hook script to CTs with the config property `hookscript`.
606 # pct set 100 -hookscript local:snippets/hookscript.pl
609 It will be called during various phases of the guests lifetime. For an example
610 and documentation see the example script under
611 `/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
613 Security Considerations
614 -----------------------
616 Containers use the kernel of the host system. This exposes an attack surface
617 for malicious users. In general, full virtual machines provide better
618 isolation. This should be considered if containers are provided to unknown or
621 To reduce the attack surface, LXC uses many security features like AppArmor,
622 CGroups and kernel namespaces.
627 AppArmor profiles are used to restrict access to possibly dangerous actions.
628 Some system calls, i.e. `mount`, are prohibited from execution.
630 To trace AppArmor activity, use:
633 # dmesg | grep apparmor
636 Although it is not recommended, AppArmor can be disabled for a container. This
637 brings security risks with it. Some syscalls can lead to privilege escalation
638 when executed within a container if the system is misconfigured or if a LXC or
639 Linux Kernel vulnerability exists.
641 To disable AppArmor for a container, add the following line to the container
642 configuration file located at `/etc/pve/lxc/CTID.conf`:
645 lxc.apparmor.profile = unconfined
648 WARNING: Please note that this is not recommended for production use.
652 Control Groups ('cgroup')
653 ~~~~~~~~~~~~~~~~~~~~~~~~~
656 mechanism used to hierarchically organize processes and distribute system
659 The main resources controlled via 'cgroups' are CPU time, memory and swap
660 limits, and access to device nodes. 'cgroups' are also used to "freeze" a
661 container before taking snapshots.
663 There are 2 versions of 'cgroups' currently available,
664 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v1/index.html[legacy]
666 https://www.kernel.org/doc/html/v5.11/admin-guide/cgroup-v2.html['cgroupv2'].
668 Since {pve} 7.0, the default is a pure 'cgroupv2' environment. Previously a
669 "hybrid" setup was used, where resource control was mainly done in 'cgroupv1'
670 with an additional 'cgroupv2' controller which could take over some subsystems
671 via the 'cgroup_no_v1' kernel command line parameter. (See the
672 https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html[kernel
673 parameter documentation] for details.)
675 [[pct_cgroup_compat]]
676 CGroup Version Compatibility
677 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
678 The main difference between pure 'cgroupv2' and the old hybrid environments
679 regarding {pve} is that with 'cgroupv2' memory and swap are now controlled
680 independently. The memory and swap settings for containers can map directly to
681 these values, whereas previously only the memory limit and the limit of the
682 *sum* of memory and swap could be limited.
684 Another important difference is that the 'devices' controller is configured in a
685 completely different way. Because of this, file system quotas are currently not
686 supported in a pure 'cgroupv2' environment.
688 'cgroupv2' support by the container's OS is needed to run in a pure 'cgroupv2'
689 environment. Containers running 'systemd' version 231 or newer support
690 'cgroupv2' footnote:[this includes all newest major versions of container
691 templates shipped by {pve}], as do containers not using 'systemd' as init
692 system footnote:[for example Alpine Linux].
696 CentOS 7 and Ubuntu 16.10 are two prominent Linux distributions releases,
697 which have a 'systemd' version that is too old to run in a 'cgroupv2'
698 environment, you can either
700 * Upgrade the whole distribution to a newer release. For the examples above, that
701 could be Ubuntu 18.04 or 20.04, and CentOS 8 (or RHEL/CentOS derivatives like
702 AlmaLinux or Rocky Linux). This has the benefit to get the newest bug and
703 security fixes, often also new features, and moving the EOL date in the future.
705 * Upgrade the Containers systemd version. If the distribution provides a
706 backports repository this can be an easy and quick stop-gap measurement.
708 * Move the container, or its services, to a Virtual Machine. Virtual Machines
709 have a much less interaction with the host, that's why one can install
710 decades old OS versions just fine there.
712 * Switch back to the legacy 'cgroup' controller. Note that while it can be a
713 valid solution, it's not a permanent one. There's a high likelihood that a
714 future {pve} major release, for example 8.0, cannot support the legacy
718 [[pct_cgroup_change_version]]
719 Changing CGroup Version
720 ^^^^^^^^^^^^^^^^^^^^^^^
722 TIP: If file system quotas are not required and all containers support 'cgroupv2',
723 it is recommended to stick to the new default.
725 To switch back to the previous version the following kernel command line
726 parameter can be used:
729 systemd.unified_cgroup_hierarchy=0
732 See xref:sysboot_edit_kernel_cmdline[this section] on editing the kernel boot
733 command line on where to add the parameter.
735 // TODO: seccomp a bit more.
736 // TODO: pve-lxc-syscalld
739 Guest Operating System Configuration
740 ------------------------------------
742 {pve} tries to detect the Linux distribution in the container, and modifies
743 some files. Here is a short list of things done at container startup:
745 set /etc/hostname:: to set the container name
747 modify /etc/hosts:: to allow lookup of the local hostname
749 network setup:: pass the complete network setup to the container
751 configure DNS:: pass information about DNS servers
753 adapt the init system:: for example, fix the number of spawned getty processes
755 set the root password:: when creating a new container
757 rewrite ssh_host_keys:: so that each container has unique keys
759 randomize crontab:: so that cron does not start at the same time on all containers
761 Changes made by {PVE} are enclosed by comment markers:
769 Those markers will be inserted at a reasonable location in the file. If such a
770 section already exists, it will be updated in place and will not be moved.
772 Modification of a file can be prevented by adding a `.pve-ignore.` file for it.
773 For instance, if the file `/etc/.pve-ignore.hosts` exists then the `/etc/hosts`
774 file will not be touched. This can be a simple empty file created via:
777 # touch /etc/.pve-ignore.hosts
780 Most modifications are OS dependent, so they differ between different
781 distributions and versions. You can completely disable modifications by
782 manually setting the `ostype` to `unmanaged`.
784 OS type detection is done by testing for certain files inside the
785 container. {pve} first checks the `/etc/os-release` file
786 footnote:[/etc/os-release replaces the multitude of per-distribution
787 release files https://manpages.debian.org/stable/systemd/os-release.5.en.html].
788 If that file is not present, or it does not contain a clearly recognizable
789 distribution identifier the following distribution specific release files are
792 Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`)
794 Debian:: test /etc/debian_version
796 Fedora:: test /etc/fedora-release
798 RedHat or CentOS:: test /etc/redhat-release
800 ArchLinux:: test /etc/arch-release
802 Alpine:: test /etc/alpine-release
804 Gentoo:: test /etc/gentoo-release
806 NOTE: Container start fails if the configured `ostype` differs from the auto
810 [[pct_container_storage]]
814 The {pve} LXC container storage model is more flexible than traditional
815 container storage models. A container can have multiple mount points. This
816 makes it possible to use the best suited storage for each application.
818 For example the root file system of the container can be on slow and cheap
819 storage while the database can be on fast and distributed storage via a second
820 mount point. See section <<pct_mount_points, Mount Points>> for further
823 Any storage type supported by the {pve} storage library can be used. This means
824 that containers can be stored on local (for example `lvm`, `zfs` or directory),
825 shared external (like `iSCSI`, `NFS`) or even distributed storage systems like
826 Ceph. Advanced storage features like snapshots or clones can be used if the
827 underlying storage supports them. The `vzdump` backup tool can use snapshots to
828 provide consistent container backups.
830 Furthermore, local devices or local directories can be mounted directly using
831 'bind mounts'. This gives access to local resources inside a container with
832 practically zero overhead. Bind mounts can be used as an easy way to share data
839 WARNING: Because of existing issues in the Linux kernel's freezer subsystem the
840 usage of FUSE mounts inside a container is strongly advised against, as
841 containers need to be frozen for suspend or snapshot mode backups.
843 If FUSE mounts cannot be replaced by other mounting mechanisms or storage
844 technologies, it is possible to establish the FUSE mount on the Proxmox host
845 and use a bind mount point to make it accessible inside the container.
848 Using Quotas Inside Containers
849 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
851 Quotas allow to set limits inside a container for the amount of disk space that
854 NOTE: This currently requires the use of legacy 'cgroups'.
856 NOTE: This only works on ext4 image based storage types and currently only
857 works with privileged containers.
859 Activating the `quota` option causes the following mount options to be used for
861 `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0`
863 This allows quotas to be used like on any other system. You can initialize the
864 `/aquota.user` and `/aquota.group` files by running:
871 Then edit the quotas using the `edquota` command. Refer to the documentation of
872 the distribution running inside the container for details.
874 NOTE: You need to run the above commands for every mount point by passing the
875 mount point's path instead of just `/`.
878 Using ACLs Inside Containers
879 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
881 The standard Posix **A**ccess **C**ontrol **L**ists are also available inside
882 containers. ACLs allow you to set more detailed file ownership than the
883 traditional user/group/others model.
886 Backup of Container mount points
887 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
889 To include a mount point in backups, enable the `backup` option for it in the
890 container configuration. For an existing mount point `mp0`
893 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G
896 add `backup=1` to enable it.
899 mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G,backup=1
902 NOTE: When creating a new mount point in the GUI, this option is enabled by
905 To disable backups for a mount point, add `backup=0` in the way described
906 above, or uncheck the *Backup* checkbox on the GUI.
908 Replication of Containers mount points
909 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
911 By default, additional mount points are replicated when the Root Disk is
912 replicated. If you want the {pve} storage replication mechanism to skip a mount
913 point, you can set the *Skip replication* option for that mount point.
914 As of {pve} 5.0, replication requires a storage of type `zfspool`. Adding a
915 mount point to a different type of storage when the container has replication
916 configured requires to have *Skip replication* enabled for that mount point.
926 It is possible to use the `vzdump` tool for container backup. Please refer to
927 the `vzdump` manual page for details.
930 Restoring Container Backups
931 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
933 Restoring container backups made with `vzdump` is possible using the `pct
934 restore` command. By default, `pct restore` will attempt to restore as much of
935 the backed up container configuration as possible. It is possible to override
936 the backed up configuration by manually setting container options on the
937 command line (see the `pct` manual page for details).
939 NOTE: `pvesm extractconfig` can be used to view the backed up configuration
940 contained in a vzdump archive.
942 There are two basic restore modes, only differing by their handling of mount
946 ``Simple'' Restore Mode
947 ^^^^^^^^^^^^^^^^^^^^^^^
949 If neither the `rootfs` parameter nor any of the optional `mpX` parameters are
950 explicitly set, the mount point configuration from the backed up configuration
951 file is restored using the following steps:
953 . Extract mount points and their options from backup
954 . Create volumes for storage backed mount points on the storage provided with
955 the `storage` parameter (default: `local`).
956 . Extract files from backup archive
957 . Add bind and device mount points to restored configuration (limited to root
960 NOTE: Since bind and device mount points are never backed up, no files are
961 restored in the last step, but only the configuration options. The assumption
962 is that such mount points are either backed up with another mechanism (e.g.,
963 NFS space that is bind mounted into many containers), or not intended to be
966 This simple mode is also used by the container restore operations in the web
970 ``Advanced'' Restore Mode
971 ^^^^^^^^^^^^^^^^^^^^^^^^^
973 By setting the `rootfs` parameter (and optionally, any combination of `mpX`
974 parameters), the `pct restore` command is automatically switched into an
975 advanced mode. This advanced mode completely ignores the `rootfs` and `mpX`
976 configuration options contained in the backup archive, and instead only uses
977 the options explicitly provided as parameters.
979 This mode allows flexible configuration of mount point settings at restore
982 * Set target storages, volume sizes and other options for each mount point
984 * Redistribute backed up files according to new mount point scheme
985 * Restore to device and/or bind mount points (limited to root user)
988 Managing Containers with `pct`
989 ------------------------------
991 The ``Proxmox Container Toolkit'' (`pct`) is the command line tool to manage
992 {pve} containers. It enables you to create or destroy containers, as well as
993 control the container execution (start, stop, reboot, migrate, etc.). It can be
994 used to set parameters in the config file of a container, for example the
995 network configuration or memory limits.
1000 Create a container based on a Debian template (provided you have already
1001 downloaded the template via the web interface)
1004 # pct create 100 /var/lib/vz/template/cache/debian-10.0-standard_10.0-1_amd64.tar.gz
1013 Start a login session via getty
1019 Enter the LXC namespace and run a shell as root user
1025 Display the configuration
1031 Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, set
1032 the address and gateway, while it's running
1035 # pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1
1038 Reduce the memory of the container to 512MB
1041 # pct set 100 -memory 512
1044 Destroying a container always removes it from Access Control Lists and it always
1045 removes the firewall configuration of the container. You have to activate
1046 '--purge', if you want to additionally remove the container from replication jobs,
1047 backup jobs and HA resource configurations.
1050 # pct destroy 100 --purge
1053 Move a mount point volume to a different storage.
1056 # pct move-volume 100 mp0 other-storage
1059 Reassign a volume to a different CT. This will remove the volume `mp0` from
1060 the source CT and attaches it as `mp1` to the target CT. In the background
1061 the volume is being renamed so that the name matches the new owner.
1064 # pct move-volume 100 mp0 --target-vmid 200 --target-volume mp1
1068 Obtaining Debugging Logs
1069 ~~~~~~~~~~~~~~~~~~~~~~~~
1071 In case `pct start` is unable to start a specific container, it might be
1072 helpful to collect debugging output by passing the `--debug` flag (replace `CTID` with
1073 the container's CTID):
1076 # pct start CTID --debug
1079 Alternatively, you can use the following `lxc-start` command, which will save
1080 the debug log to the file specified by the `-o` output option:
1083 # lxc-start -n CTID -F -l DEBUG -o /tmp/lxc-CTID.log
1086 This command will attempt to start the container in foreground mode, to stop
1087 the container run `pct shutdown CTID` or `pct stop CTID` in a second terminal.
1089 The collected debug log is written to `/tmp/lxc-CTID.log`.
1091 NOTE: If you have changed the container's configuration since the last start
1092 attempt with `pct start`, you need to run `pct start` at least once to also
1093 update the configuration used by `lxc-start`.
1099 If you have a cluster, you can migrate your Containers with
1102 # pct migrate <ctid> <target>
1105 This works as long as your Container is offline. If it has local volumes or
1106 mount points defined, the migration will copy the content over the network to
1107 the target host if the same storage is defined there.
1109 Running containers cannot live-migrated due to technical limitations. You can
1110 do a restart migration, which shuts down, moves and then starts a container
1111 again on the target node. As containers are very lightweight, this results
1112 normally only in a downtime of some hundreds of milliseconds.
1114 A restart migration can be done through the web interface or by using the
1115 `--restart` flag with the `pct migrate` command.
1117 A restart migration will shut down the Container and kill it after the
1118 specified timeout (the default is 180 seconds). Then it will migrate the
1119 Container like an offline migration and when finished, it starts the Container
1122 [[pct_configuration]]
1126 The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, where
1127 `<CTID>` is the numeric ID of the given container. Like all other files stored
1128 inside `/etc/pve/`, they get automatically replicated to all other cluster
1131 NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be
1132 unique cluster wide.
1134 .Example Container Configuration
1141 net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth
1142 rootfs: local:107/vm-107-disk-1.raw,size=7G
1145 The configuration files are simple text files. You can edit them using a normal
1146 text editor, for example, `vi` or `nano`.
1147 This is sometimes useful to do small corrections, but keep in mind that you
1148 need to restart the container to apply such changes.
1150 For that reason, it is usually better to use the `pct` command to generate and
1151 modify those files, or do the whole thing using the GUI.
1152 Our toolkit is smart enough to instantaneously apply most changes to running
1153 containers. This feature is called ``hot plug'', and there is no need to restart
1154 the container in that case.
1156 In cases where a change cannot be hot-plugged, it will be registered as a
1157 pending change (shown in red color in the GUI).
1158 They will only be applied after rebooting the container.
1164 The container configuration file uses a simple colon separated key/value
1165 format. Each line has the following format:
1172 Blank lines in those files are ignored, and lines starting with a `#` character
1173 are treated as comments and are also ignored.
1175 It is possible to add low-level, LXC style configuration directly, for example:
1178 lxc.init_cmd: /sbin/my_own_init
1184 lxc.init_cmd = /sbin/my_own_init
1187 The settings are passed directly to the LXC low-level tools.
1194 When you create a snapshot, `pct` stores the configuration at snapshot time
1195 into a separate snapshot section within the same configuration file. For
1196 example, after creating a snapshot called ``testsnapshot'', your configuration
1197 file will look like this:
1199 .Container configuration with snapshot
1209 snaptime: 1457170803
1213 There are a few snapshot related properties like `parent` and `snaptime`. The
1214 `parent` property is used to store the parent/child relationship between
1215 snapshots. `snaptime` is the snapshot creation time stamp (Unix epoch).
1222 include::pct.conf.5-opts.adoc[]
1228 Container migrations, snapshots and backups (`vzdump`) set a lock to prevent
1229 incompatible concurrent actions on the affected container. Sometimes you need
1230 to remove such a lock manually (e.g., after a power failure).
1236 CAUTION: Only do this if you are sure the action which set the lock is no
1245 `/etc/pve/lxc/<CTID>.conf`::
1247 Configuration file for the container '<CTID>'.
1250 include::pve-copyright.adoc[]