+[[chapter_pct]]
ifdef::manvolnum[]
-PVE({manvolnum})
-================
-include::attributes.txt[]
+pct(1)
+======
+:pve-toplevel:
NAME
----
pct - Tool to manage Linux Containers (LXC) on Proxmox VE
-SYNOPSYS
+SYNOPSIS
--------
include::pct.1-synopsis.adoc[]
ifndef::manvolnum[]
Proxmox Container Toolkit
=========================
-include::attributes.txt[]
+:pve-toplevel:
endif::manvolnum[]
+ifdef::wiki[]
+:title: Linux Container
+endif::wiki[]
+Containers are a lightweight alternative to fully virtualized machines (VMs).
+They use the kernel of the host system that they run on, instead of emulating a
+full operating system (OS). This means that containers can access resources on
+the host system directly.
-Containers are a lightweight alternative to fully virtualized
-VMs. Instead of emulating a complete Operating System (OS), containers
-simply use the OS of the host they run on. This implies that all
-containers use the same kernel, and that they can access resources
-from the host directly.
+The runtime costs for containers is low, usually negligible. However, there
+are some drawbacks that need be considered:
-This is great because containers do not waste CPU power nor memory due
-to kernel emulation. Container run-time costs are close to zero and
-usually negligible. But there are also some drawbacks you need to
-consider:
+* Only Linux distributions can be run in containers. (It is not
+ possible to run FreeBSD or MS Windows inside a container.)
-* You can only run Linux based OS inside containers, i.e. it is not
- possible to run FreeBSD or MS Windows inside.
-
-* For security reasons, access to host resources needs to be
- restricted. This is done with AppArmor, SecComp filters and other
- kernel features. Be prepared that some syscalls are not allowed
- inside containers.
+* For security reasons, access to host resources needs to be restricted. Containers
+ run in their own separate namespaces. Additionally some syscalls are not
+ allowed within containers.
{pve} uses https://linuxcontainers.org/[LXC] as underlying container
-technology. We consider LXC as low-level library, which provides
-countless options. It would be too difficult to use those tools
-directly. Instead, we provide a small wrapper called `pct`, the
-"Proxmox Container Toolkit".
+technology. The ``Proxmox Container Toolkit'' (`pct`) simplifies the usage of LXC
+containers.
-The toolkit is tightly coupled with {pve}. That means that it is aware
-of the cluster setup, and it can use the same network and storage
-resources as fully virtualized VMs. You can even use the {pve}
-firewall, or manage containers using the HA framework.
+Containers are tightly integrated with {pve}. This means that they are aware of
+the cluster setup, and they can use the same network and storage resources as
+virtual machines. You can also use the {pve} firewall, or manage containers
+using the HA framework.
Our primary goal is to offer an environment as one would get from a
VM, but without the additional overhead. We call this "System
Containers".
-NOTE: If you want to run micro-containers (with docker, rkt, ...), it
+NOTE: If you want to run micro-containers (with docker, rkt, etc.) it
is best to run them inside a VM.
-Security Considerations
------------------------
-
-Containers use the same kernel as the host, so there is a big attack
-surface for malicious users. You should consider this fact if you
-provide containers to totally untrusted people. In general, fully
-virtualized VMs provide better isolation.
-
-The good news is that LXC uses many kernel security features like
-AppArmor, CGroups and PID and user namespaces, which makes containers
-usage quite secure. We distinguish two types of containers:
-
-Privileged containers
-~~~~~~~~~~~~~~~~~~~~~
-
-Security is done by dropping capabilities, using mandatory access
-control (AppArmor), SecComp filters and namespaces. The LXC team
-considers this kind of container as unsafe, and they will not consider
-new container escape exploits to be security issues worthy of a CVE
-and quick fix. So you should use this kind of containers only inside a
-trusted environment, or when no untrusted task is running as root in
-the container.
-
-Unprivileged containers
-~~~~~~~~~~~~~~~~~~~~~~~
-
-This kind of containers use a new kernel feature called user
-namespaces. The root uid 0 inside the container is mapped to an
-unprivileged user outside the container. This means that most security
-issues (container escape, resource abuse, ...) in those containers
-will affect a random unprivileged user, and so would be a generic
-kernel security bug rather than an LXC issue. The LXC team thinks
-unprivileged containers are safe by design.
-
-
-Configuration
--------------
+Technology Overview
+-------------------
-The '/etc/pve/lxc/<CTID>.conf' file stores container configuration,
-where '<CTID>' is the numeric ID of the given container. Like all
-other files stored inside '/etc/pve/', they get automatically
-replicated to all other cluster nodes.
+* LXC (https://linuxcontainers.org/)
-NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be
-unique cluster wide.
+* Integrated into {pve} graphical user interface (GUI)
-.Example Container Configuration
-----
-ostype: debian
-arch: amd64
-hostname: www
-memory: 512
-swap: 512
-net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth
-rootfs: local:107/vm-107-disk-1.raw,size=7G
-----
+* Easy to use command line tool `pct`
-Those configuration files are simple text files, and you can edit them
-using a normal text editor ('vi', 'nano', ...). This is sometimes
-useful to do small corrections, but keep in mind that you need to
-restart the container to apply such changes.
+* Access via {pve} REST API
-For that reason, it is usually better to use the 'pct' command to
-generate and modify those files, or do the whole thing using the GUI.
-Our toolkit is smart enough to instantaneously apply most changes to
-running containers. This feature is called "hot plug", and there is no
-need to restart the container in that case.
+* lxcfs to provide containerized /proc file system
-File Format
-~~~~~~~~~~~
+* CGroups (control groups) for resource allocation
-Container configuration files use a simple colon separated key/value
-format. Each line has the following format:
+* AppArmor/Seccomp to improve security
- # this is a comment
- OPTION: value
+* Modern Linux kernels
-Blank lines in those files are ignored, and lines starting with a '#'
-character are treated as comments and are also ignored.
+* Image based deployment (templates)
-It is possible to add low-level, LXC style configuration directly, for
-example:
+* Uses {pve} storage library
- lxc.init_cmd: /sbin/my_own_init
+* Container setup from host (network, DNS, storage, etc.)
-or
+Security Considerations
+-----------------------
- lxc.init_cmd = /sbin/my_own_init
+Containers use the kernel of the host system. This creates a big attack
+surface for malicious users. This should be considered if containers
+are provided to untrustworthy people. In general, full
+virtual machines provide better isolation.
-Those settings are directly passed to the LXC low-level tools.
+However, LXC uses many security features like AppArmor, CGroups and kernel
+namespaces to reduce the attack surface.
-Snapshots
-~~~~~~~~~
+AppArmor profiles are used to restrict access to possibly dangerous actions.
+Some system calls, i.e. `mount`, are prohibited from execution.
-When you create a snapshot, 'pct' stores the configuration at snapshot
-time into a separate snapshot section within the same configuration
-file. For example, after creating a snapshot called 'testsnapshot',
-your configuration file will look like this:
+To trace AppArmor activity, use:
-.Container Configuration with Snapshot
----
-memory: 512
-swap: 512
-parent: testsnaphot
-...
-
-[testsnaphot]
-memory: 512
-swap: 512
-snaptime: 1457170803
-...
+# dmesg | grep apparmor
----
-There are a few snapshot related properties like 'parent' and
-'snaptime'. The 'parent' property is used to store the parent/child
-relationship between snapshots. 'snaptime' is the snapshot creation
-time stamp (unix epoch).
-
Guest Operating System Configuration
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+------------------------------------
-We normally try to detect the operating system type inside the
-container, and then modify some files inside the container to make
-them work as expected. Here is a short list of things we do at
-container startup:
+{pve} tries to detect the Linux distribution in the container, and modifies some
+files. Here is a short list of things done at container startup:
set /etc/hostname:: to set the container name
Modification of a file can be prevented by adding a `.pve-ignore.`
file for it. For instance, if the file `/etc/.pve-ignore.hosts`
exists then the `/etc/hosts` file will not be touched. This can be a
-simple empty file creatd via:
+simple empty file created via:
- # touch /etc/.pve-ignore.hosts
+----
+# touch /etc/.pve-ignore.hosts
+----
Most modifications are OS dependent, so they differ between different
distributions and versions. You can completely disable modifications
-by manually setting the 'ostype' to 'unmanaged'.
+by manually setting the `ostype` to `unmanaged`.
OS type detection is done by testing for certain files inside the
container:
-Ubuntu:: inspect /etc/lsb-release ('DISTRIB_ID=Ubuntu')
+Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`)
Debian:: test /etc/debian_version
Gentoo:: test /etc/gentoo-release
-NOTE: Container start fails if the configured 'ostype' differs from the auto
+NOTE: Container start fails if the configured `ostype` differs from the auto
detected type.
-Options
-~~~~~~~
-
-include::pct.conf.5-opts.adoc[]
-
+[[pct_container_images]]
Container Images
----------------
-Container Images, sometimes also referred to as "templates" or
-"appliances", are 'tar' archives which contain everything to run a
-container. You can think of it as a tidy container backup. Like most
-modern container toolkits, 'pct' uses those images when you create a
-new container, for example:
+Container images, sometimes also referred to as ``templates'' or
+``appliances'', are `tar` archives which contain everything to run a
+container. `pct` uses them to create a new container, for example:
- pct create 999 local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz
+----
+# pct create 999 local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
+----
-Proxmox itself ships a set of basic templates for most common
-operating systems, and you can download them using the 'pveam' (short
-for {pve} Appliance Manager) command line utility. You can also
-download https://www.turnkeylinux.org/[TurnKey Linux] containers using
-that tool (or the graphical user interface).
+{pve} itself provides a variety of basic templates for the most common
+Linux distributions. They can be downloaded using the GUI or the
+`pveam` (short for {pve} Appliance Manager) command line utility.
+Additionally, https://www.turnkeylinux.org/[TurnKey Linux]
+container templates are also available to download.
-Our image repositories contain a list of available images, and there
-is a cron job run each day to download that list. You can trigger that
-update manually with:
+The list of available templates is updated daily via cron. To trigger it manually:
- pveam update
+----
+# pveam update
+----
-After that you can view the list of available images using:
+To view the list of available images run:
- pveam available
+----
+# pveam available
+----
-You can restrict this large list by specifying the 'section' you are
-interested in, for example basic 'system' images:
+You can restrict this large list by specifying the `section` you are
+interested in, for example basic `system` images:
.List available system images
----
# pveam available --section system
-system archlinux-base_2015-24-29-1_x86_64.tar.gz
-system centos-7-default_20160205_amd64.tar.xz
-system debian-6.0-standard_6.0-7_amd64.tar.gz
-system debian-7.0-standard_7.0-3_amd64.tar.gz
-system debian-8.0-standard_8.0-1_amd64.tar.gz
-system ubuntu-12.04-standard_12.04-1_amd64.tar.gz
-system ubuntu-14.04-standard_14.04-1_amd64.tar.gz
-system ubuntu-15.04-standard_15.04-1_amd64.tar.gz
-system ubuntu-15.10-standard_15.10-1_amd64.tar.gz
+system alpine-3.10-default_20190626_amd64.tar.xz
+system alpine-3.9-default_20190224_amd64.tar.xz
+system archlinux-base_20190924-1_amd64.tar.gz
+system centos-6-default_20191016_amd64.tar.xz
+system centos-7-default_20190926_amd64.tar.xz
+system centos-8-default_20191016_amd64.tar.xz
+system debian-10.0-standard_10.0-1_amd64.tar.gz
+system debian-8.0-standard_8.11-1_amd64.tar.gz
+system debian-9.0-standard_9.7-1_amd64.tar.gz
+system fedora-30-default_20190718_amd64.tar.xz
+system fedora-31-default_20191029_amd64.tar.xz
+system gentoo-current-default_20190718_amd64.tar.xz
+system opensuse-15.0-default_20180907_amd64.tar.xz
+system opensuse-15.1-default_20190719_amd64.tar.xz
+system ubuntu-16.04-standard_16.04.5-1_amd64.tar.gz
+system ubuntu-18.04-standard_18.04.1-1_amd64.tar.gz
+system ubuntu-19.04-standard_19.04-1_amd64.tar.gz
+system ubuntu-19.10-standard_19.10-1_amd64.tar.gz
----
Before you can use such a template, you need to download them into one
-of your storages. You can simply use storage 'local' for that
+of your storages. You can simply use storage `local` for that
purpose. For clustered installations, it is preferred to use a shared
storage so that all nodes can access those images.
- pveam download local debian-8.0-standard_8.0-1_amd64.tar.gz
+----
+# pveam download local debian-10.0-standard_10.0-1_amd64.tar.gz
+----
You are now ready to create containers using that image, and you can
-list all downloaded images on storage 'local' with:
+list all downloaded images on storage `local` with:
----
# pveam list local
-local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz 190.20MB
+local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz 219.95MB
----
The above command shows you the full {pve} volume identifiers. They include
the storage name, and most other {pve} commands can use them. For
-examply you can delete that image later with:
-
- pveam remove local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz
+example you can delete that image later with:
+----
+# pveam remove local:vztmpl/debian-10.0-standard_10.0-1_amd64.tar.gz
+----
+[[pct_container_storage]]
Container Storage
-----------------
-Traditional containers use a very simple storage model, only allowing
-a single mount point, the root file system. This was further
-restricted to specific file system types like 'ext4' and 'nfs'.
-Additional mounts are often done by user provided scripts. This turend
-out to be complex and error prone, so we try to avoid that now.
-
-Our new LXC based container model is more flexible regarding
-storage. First, you can have more than a single mount point. This
-allows you to choose a suitable storage for each application. For
-example, you can use a relatively slow (and thus cheap) storage for
-the container root file system. Then you can use a second mount point
-to mount a very fast, distributed storage for your database
-application.
-
-The second big improvement is that you can use any storage type
-supported by the {pve} storage library. That means that you can store
-your containers on local 'lvmthin' or 'zfs', shared 'iSCSI' storage,
-or even on distributed storage systems like 'ceph'. It also enables us
-to use advanced storage features like snapshots and clones. 'vzdump'
-can also use the snapshot feature to provide consistent container
-backups.
-
-Last but not least, you can also mount local devices directly, or
-mount local directories using bind mounts. That way you can access
-local storage inside containers with zero overhead. Such bind mounts
-also provide an easy way to share data between different containers.
+The {pve} LXC container storage model is more flexible than traditional
+container storage models. A container can have multiple mount points. This makes
+it possible to use the best suited storage for each application.
+
+For example the root file system of the container can be on slow and cheap
+storage while the database can be on fast and distributed storage via a second
+mount point. See section <<pct_mount_points, Mount Points>> for further details.
+
+Any storage type supported by the {pve} storage library can be used. This means
+that containers can be stored on local (for example `lvm`, `zfs` or directory),
+shared external (like `iSCSI`, `NFS`) or even distributed storage systems like
+Ceph. Advanced storage features like snapshots or clones can be used if the
+underlying storage supports them. The `vzdump` backup tool can use snapshots to
+provide consistent container backups.
+
+Furthermore, local devices or local directories can be mounted directly using
+'bind mounts'. This gives access to local resources inside a container with
+practically zero overhead. Bind mounts can be used as an easy way to share data
+between containers.
+
+
+FUSE Mounts
+~~~~~~~~~~~
+
+WARNING: Because of existing issues in the Linux kernel's freezer
+subsystem the usage of FUSE mounts inside a container is strongly
+advised against, as containers need to be frozen for suspend or
+snapshot mode backups.
+
+If FUSE mounts cannot be replaced by other mounting mechanisms or storage
+technologies, it is possible to establish the FUSE mount on the Proxmox host
+and use a bind mount point to make it accessible inside the container.
+
+
+Using Quotas Inside Containers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Quotas allow to set limits inside a container for the amount of disk
+space that each user can use.
+
+NOTE: This only works on ext4 image based storage types and currently only works
+with privileged containers.
+
+Activating the `quota` option causes the following mount options to be
+used for a mount point:
+`usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0`
+
+This allows quotas to be used like on any other system. You
+can initialize the `/aquota.user` and `/aquota.group` files by running
+
+----
+# quotacheck -cmug /
+# quotaon /
+----
+
+and edit the quotas via the `edquota` command. Refer to the documentation
+of the distribution running inside the container for details.
+
+NOTE: You need to run the above commands for every mount point by passing
+the mount point's path instead of just `/`.
+
+
+Using ACLs Inside Containers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The standard Posix **A**ccess **C**ontrol **L**ists are also available inside
+containers. ACLs allow you to set more detailed file ownership than the
+traditional user/group/others model.
+
+
+Backup of Container mount points
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To include a mount point in backups, enable the `backup` option for it in the
+container configuration. For an existing mount point `mp0`
+
+----
+mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G
+----
+
+add `backup=1` to enable it.
+
+----
+mp0: guests:subvol-100-disk-1,mp=/root/files,size=8G,backup=1
+----
+
+NOTE: When creating a new mount point in the GUI, this option is enabled by
+default.
+
+To disable backups for a mount point, add `backup=0` in the way described above,
+or uncheck the *Backup* checkbox on the GUI.
+
+Replication of Containers mount points
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default, additional mount points are replicated when the Root Disk is
+replicated. If you want the {pve} storage replication mechanism to skip a mount
+point, you can set the *Skip replication* option for that mount point. +
+As of {pve} 5.0, replication requires a storage of type `zfspool`. Adding a
+mount point to a different type of storage when the container has replication
+configured requires to have *Skip replication* enabled for that mount point.
+
+[[pct_settings]]
+Container Settings
+------------------
+
+[[pct_general]]
+General Settings
+~~~~~~~~~~~~~~~~
+
+[thumbnail="screenshot/gui-create-ct-general.png"]
+
+General settings of a container include
+
+* the *Node* : the physical server on which the container will run
+* the *CT ID*: a unique number in this {pve} installation used to identify your container
+* *Hostname*: the hostname of the container
+* *Resource Pool*: a logical group of containers and VMs
+* *Password*: the root password of the container
+* *SSH Public Key*: a public key for connecting to the root account over SSH
+* *Unprivileged container*: this option allows to choose at creation time
+if you want to create a privileged or unprivileged container.
+
+Unprivileged Containers
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Unprivileged containers use a new kernel feature called user namespaces. The
+root UID 0 inside the container is mapped to an unprivileged user outside the
+container. This means that most security issues (container escape, resource
+abuse, etc.) in these containers will affect a random unprivileged user, and
+would be a generic kernel security bug rather than an LXC issue. The LXC team
+thinks unprivileged containers are safe by design.
+
+This is the default option when creating a new container.
+
+NOTE: If the container uses systemd as an init system, please be
+aware the systemd version running inside the container should be equal to
+or greater than 220.
+
+
+Privileged Containers
+^^^^^^^^^^^^^^^^^^^^^
+
+Security in containers is achieved by using mandatory access control
+(AppArmor), SecComp filters and namespaces. The LXC team considers this kind of
+container as unsafe, and they will not consider new container escape exploits
+to be security issues worthy of a CVE and quick fix. That's why privileged
+containers should only be used in trusted environments.
+
+WARNING: Although it is not recommended, AppArmor can be disabled for a
+container. This brings security risks with it. Some syscalls can lead to
+privilege escalation when executed within a container if the system is
+misconfigured or if a LXC or Linux Kernel vulnerability exists.
+
+To disable AppArmor for a container, add the following line to the container
+configuration file located at `/etc/pve/lxc/CTID.conf`:
+
+----
+lxc.apparmor_profile = unconfined
+----
+
+Please note that this is not recommended for production use.
+
+
+
+[[pct_cpu]]
+CPU
+~~~
+
+[thumbnail="screenshot/gui-create-ct-cpu.png"]
+
+You can restrict the number of visible CPUs inside the container using the
+`cores` option. This is implemented using the Linux 'cpuset' cgroup
+(**c**ontrol *group*). A special task inside `pvestatd` tries to distribute
+running containers among available CPUs. To view the assigned CPUs run
+the following command:
+
+----
+# pct cpusets
+ ---------------------
+ 102: 6 7
+ 105: 2 3 4 5
+ 108: 0 1
+ ---------------------
+----
+
+Containers use the host kernel directly. All tasks inside a container are
+handled by the host CPU scheduler. {pve} uses the Linux 'CFS' (**C**ompletely
+**F**air **S**cheduler) scheduler by default, which has additional bandwidth
+control options.
+
+[horizontal]
+
+`cpulimit`: :: You can use this option to further limit assigned CPU
+time. Please note that this is a floating point number, so it is
+perfectly valid to assign two cores to a container, but restrict
+overall CPU consumption to half a core.
++
+----
+cores: 2
+cpulimit: 0.5
+----
+
+`cpuunits`: :: This is a relative weight passed to the kernel
+scheduler. The larger the number is, the more CPU time this container
+gets. Number is relative to the weights of all the other running
+containers. The default is 1024. You can use this setting to
+prioritize some containers.
+
+
+[[pct_memory]]
+Memory
+~~~~~~
+
+[thumbnail="screenshot/gui-create-ct-memory.png"]
+Container memory is controlled using the cgroup memory controller.
+[horizontal]
+
+`memory`: :: Limit overall memory usage. This corresponds
+to the `memory.limit_in_bytes` cgroup setting.
+
+`swap`: :: Allows the container to use additional swap memory from the
+host swap space. This corresponds to the `memory.memsw.limit_in_bytes`
+cgroup setting, which is set to the sum of both value (`memory +
+swap`).
+
+
+[[pct_mount_points]]
Mount Points
~~~~~~~~~~~~
-The root mount point is configured with the `rootfs` property, and you can
-configure up to 10 additional mount points. The corresponding options
-are called `mp0` to `mp9`, and they can contain the following setting:
+[thumbnail="screenshot/gui-create-ct-root-disk.png"]
+
+The root mount point is configured with the `rootfs` property. You can
+configure up to 256 additional mount points. The corresponding options
+are called `mp0` to `mp255`. They can contain the following settings:
include::pct-mountpoint-opts.adoc[]
-Currently there are basically three types of mount points: storage backed
-mount points, bind mounts and device mounts.
+Currently there are three types of mount points: storage backed
+mount points, bind mounts, and device mounts.
-.Typical Container `rootfs` configuration
+.Typical container `rootfs` configuration
----
rootfs: thin1:base-100-disk-1,size=8G
----
-Storage backed mount points
+Storage Backed Mount Points
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Storage backed mount points are managed by the {pve} storage subsystem and come
in three different flavors:
-- Image based: These are raw images containing a single ext4 formatted file
+- Image based: these are raw images containing a single ext4 formatted file
system.
-- ZFS Subvolumes: These are technically bind mounts, but with managed storage,
+- ZFS subvolumes: these are technically bind mounts, but with managed storage,
and thus allow resizing and snapshotting.
- Directories: passing `size=0` triggers a special case where instead of a raw
image a directory is created.
+NOTE: The special option syntax `STORAGE_ID:SIZE_IN_GB` for storage backed
+mount point volumes will automatically allocate a volume of the specified size
+on the specified storage. E.g., calling
+`pct set 100 -mp0 thin1:10,mp=/path/in/container` will allocate a 10GB volume
+on the storage `thin1` and replace the volume ID place holder `10` with the
+allocated volume ID.
-Bind mount points
+
+Bind Mount Points
^^^^^^^^^^^^^^^^^
Bind mounts allow you to access arbitrary directories from your Proxmox VE host
unprivileged containers you might run into permission problems caused by the
user mapping and cannot use ACLs.
-NOTE: The contents of bind mount points are not backed up when using 'vzdump'.
+NOTE: The contents of bind mount points are not backed up when using `vzdump`.
WARNING: For security reasons, bind mounts should only be established
using source directories especially reserved for this purpose, e.g., a
For example, to make the directory `/mnt/bindmounts/shared` accessible in the
container with ID `100` under the path `/shared`, use a configuration line like
-'mp0: /mnt/bindmounts/shared,mp=/shared' in '/etc/pve/lxc/100.conf'.
-Alternatively, use 'pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared' to
+`mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`.
+Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to
achieve the same result.
-Device mount points
+Device Mount Points
^^^^^^^^^^^^^^^^^^^
Device mount points allow to mount block devices of the host directly into the
most cases a storage backed mount point offers the same performance and a lot
more features.
-NOTE: The contents of device mount points are not backed up when using 'vzdump'.
-
+NOTE: The contents of device mount points are not backed up when using `vzdump`.
-FUSE mounts
-~~~~~~~~~~~
-WARNING: Because of existing issues in the Linux kernel's freezer
-subsystem the usage of FUSE mounts inside a container is strongly
-advised against, as containers need to be frozen for suspend or
-snapshot mode backups.
+[[pct_container_network]]
+Network
+~~~~~~~
-If FUSE mounts cannot be replaced by other mounting mechanisms or storage
-technologies, it is possible to establish the FUSE mount on the Proxmox host
-and use a bind mount point to make it accessible inside the container.
+[thumbnail="screenshot/gui-create-ct-network.png"]
+You can configure up to 10 network interfaces for a single
+container. The corresponding options are called `net0` to `net9`, and
+they can contain the following setting:
-Using quotas inside containers
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+include::pct-network-opts.adoc[]
-Quotas allow to set limits inside a container for the amount of disk
-space that each user can use. This only works on ext4 image based
-storage types and currently does not work with unprivileged
-containers.
-Activating the `quota` option causes the following mount options to be
-used for a mount point:
-`usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0`
+[[pct_startup_and_shutdown]]
+Automatic Start and Shutdown of Containers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-This allows quotas to be used like you would on any other system. You
-can initialize the `/aquota.user` and `/aquota.group` files by running
+To automatically start a container when the host system boots, select the
+option 'Start at boot' in the 'Options' panel of the container in the web
+interface or run the following command:
----
-quotacheck -cmug /
-quotaon /
+# pct set CTID -onboot 1
----
-and edit the quotas via the `edquota` command. Refer to the documentation
-of the distribution running inside the container for details.
-
-NOTE: You need to run the above commands for every mount point by passing
-the mount point's path instead of just `/`.
-
-
-Using ACLs inside containers
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-The standard Posix Access Control Lists are also available inside containers.
-ACLs allow you to set more detailed file ownership than the traditional user/
-group/others model.
-
-
-Container Network
------------------
+.Start and Shutdown Order
+// use the screenshot from qemu - its the same
+[thumbnail="screenshot/gui-qemu-edit-start-order.png"]
+
+If you want to fine tune the boot order of your containers, you can use the following
+parameters:
+
+* *Start/Shutdown order*: Defines the start order priority. For example, set it to 1 if
+you want the CT to be the first to be started. (We use the reverse startup
+order for shutdown, so a container with a start order of 1 would be the last to
+be shut down)
+* *Startup delay*: Defines the interval between this container start and subsequent
+containers starts. For example, set it to 240 if you want to wait 240 seconds before starting
+other containers.
+* *Shutdown timeout*: Defines the duration in seconds {pve} should wait
+for the container to be offline after issuing a shutdown command.
+By default this value is set to 60, which means that {pve} will issue a
+shutdown request, wait 60s for the machine to be offline, and if after 60s
+the machine is still online will notify that the shutdown action failed.
+
+Please note that containers without a Start/Shutdown order parameter will always
+start after those where the parameter is set, and this parameter only
+makes sense between the machines running locally on a host, and not
+cluster-wide.
+
+Hookscripts
+~~~~~~~~~~~
-You can configure up to 10 network interfaces for a single
-container. The corresponding options are called 'net0' to 'net9', and
-they can contain the following setting:
+You can add a hook script to CTs with the config property `hookscript`.
-include::pct-network-opts.adoc[]
+----
+# pct set 100 -hookscript local:snippets/hookscript.pl
+----
+It will be called during various phases of the guests lifetime.
+For an example and documentation see the example script under
+`/usr/share/pve-docs/examples/guest-example-hookscript.pl`.
Backup and Restore
------------------
+
Container Backup
~~~~~~~~~~~~~~~~
-It is possible to use the 'vzdump' tool for container backup. Please
-refer to the 'vzdump' manual page for details.
+It is possible to use the `vzdump` tool for container backup. Please
+refer to the `vzdump` manual page for details.
+
Restoring Container Backups
~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Restoring container backups made with 'vzdump' is possible using the
-'pct restore' command. By default, 'pct restore' will attempt to restore as much
+Restoring container backups made with `vzdump` is possible using the
+`pct restore` command. By default, `pct restore` will attempt to restore as much
of the backed up container configuration as possible. It is possible to override
the backed up configuration by manually setting container options on the command
-line (see the 'pct' manual page for details).
+line (see the `pct` manual page for details).
-NOTE: 'pvesm extractconfig' can be used to view the backed up configuration
+NOTE: `pvesm extractconfig` can be used to view the backed up configuration
contained in a vzdump archive.
There are two basic restore modes, only differing by their handling of mount
points:
-"Simple" restore mode
-^^^^^^^^^^^^^^^^^^^^^
+``Simple'' Restore Mode
+^^^^^^^^^^^^^^^^^^^^^^^
If neither the `rootfs` parameter nor any of the optional `mpX` parameters
are explicitly set, the mount point configuration from the backed up
interface.
-"Advanced" restore mode
-^^^^^^^^^^^^^^^^^^^^^^^
+``Advanced'' Restore Mode
+^^^^^^^^^^^^^^^^^^^^^^^^^
By setting the `rootfs` parameter (and optionally, any combination of `mpX`
-parameters), the 'pct restore' command is automatically switched into an
+parameters), the `pct restore` command is automatically switched into an
advanced mode. This advanced mode completely ignores the `rootfs` and `mpX`
configuration options contained in the backup archive, and instead only
uses the options explicitly provided as parameters.
* Restore to device and/or bind mount points (limited to root user)
-Managing Containers with 'pct'
+Managing Containers with `pct`
------------------------------
-'pct' is the tool to manage Linux Containers on {pve}. You can create
-and destroy containers, and control execution (start, stop, migrate,
-...). You can use pct to set parameters in the associated config file,
-like network configuration or memory limits.
+The "Proxmox Container Toolkit" (`pct`) is the command line tool to manage {pve}
+containers. It enables you to create or destroy containers, as well as control the
+container execution (start, stop, reboot, migrate, etc.). It can be used to set
+parameters in the config file of a container, for example the network
+configuration or memory limits.
CLI Usage Examples
~~~~~~~~~~~~~~~~~~
Create a container based on a Debian template (provided you have
-already downloaded the template via the webgui)
+already downloaded the template via the web interface)
- pct create 100 /var/lib/vz/template/cache/debian-8.0-standard_8.0-1_amd64.tar.gz
+----
+# pct create 100 /var/lib/vz/template/cache/debian-10.0-standard_10.0-1_amd64.tar.gz
+----
Start container 100
- pct start 100
+----
+# pct start 100
+----
Start a login session via getty
- pct console 100
+----
+# pct console 100
+----
Enter the LXC namespace and run a shell as root user
- pct enter 100
+----
+# pct enter 100
+----
Display the configuration
- pct config 100
+----
+# pct config 100
+----
-Add a network interface called eth0, bridged to the host bridge vmbr0,
+Add a network interface called `eth0`, bridged to the host bridge `vmbr0`,
set the address and gateway, while it's running
- pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1
+----
+# pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1
+----
Reduce the memory of the container to 512MB
- pct set 100 -memory 512
+----
+# pct set 100 -memory 512
+----
-Files
-------
+Obtaining Debugging Logs
+~~~~~~~~~~~~~~~~~~~~~~~~
-'/etc/pve/lxc/<CTID>.conf'::
+In case `pct start` is unable to start a specific container, it might be
+helpful to collect debugging output by running `lxc-start` (replace `ID` with
+the container's ID):
-Configuration file for the container '<CTID>'.
+----
+# lxc-start -n ID -F -l DEBUG -o /tmp/lxc-ID.log
+----
+This command will attempt to start the container in foreground mode,
+to stop the container run `pct shutdown ID` or `pct stop ID` in a
+second terminal.
-Container Advantages
---------------------
+The collected debug log is written to `/tmp/lxc-ID.log`.
-- Simple, and fully integrated into {pve}. Setup looks similar to a normal
- VM setup.
+NOTE: If you have changed the container's configuration since the last start
+attempt with `pct start`, you need to run `pct start` at least once to also
+update the configuration used by `lxc-start`.
- * Storage (ZFS, LVM, NFS, Ceph, ...)
+[[pct_migration]]
+Migration
+---------
- * Network
+If you have a cluster, you can migrate your Containers with
- * Authentification
+----
+# pct migrate <ctid> <target>
+----
- * Cluster
+This works as long as your Container is offline. If it has local volumes or
+mount points defined, the migration will copy the content over the network to
+the target host if the same storage is defined there.
-- Fast: minimal overhead, as fast as bare metal
+If you want to migrate online Containers, the only way is to use
+restart migration. This can be initiated with the -restart flag and the optional
+-timeout parameter.
-- High density (perfect for idle workloads)
+A restart migration will shut down the Container and kill it after the specified
+timeout (the default is 180 seconds). Then it will migrate the Container
+like an offline migration and when finished, it starts the Container on the
+target node.
-- REST API
+[[pct_configuration]]
+Configuration
+-------------
-- Direct hardware access
+The `/etc/pve/lxc/<CTID>.conf` file stores container configuration,
+where `<CTID>` is the numeric ID of the given container. Like all
+other files stored inside `/etc/pve/`, they get automatically
+replicated to all other cluster nodes.
+NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be
+unique cluster wide.
-Technology Overview
--------------------
+.Example Container Configuration
+----
+ostype: debian
+arch: amd64
+hostname: www
+memory: 512
+swap: 512
+net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth
+rootfs: local:107/vm-107-disk-1.raw,size=7G
+----
+
+The configuration files are simple text files. You can edit them
+using a normal text editor (`vi`, `nano`, etc). This is sometimes
+useful to do small corrections, but keep in mind that you need to
+restart the container to apply such changes.
-- Integrated into {pve} graphical user interface (GUI)
+For that reason, it is usually better to use the `pct` command to
+generate and modify those files, or do the whole thing using the GUI.
+Our toolkit is smart enough to instantaneously apply most changes to
+running containers. This feature is called "hot plug", and there is no
+need to restart the container in that case.
+
+In cases where a change cannot be hot plugged, it will be registered
+as a pending change (shown in red color in the GUI). They will only
+be applied after rebooting the container.
+
+
+File Format
+~~~~~~~~~~~
+
+The container configuration file uses a simple colon separated
+key/value format. Each line has the following format:
-- LXC (https://linuxcontainers.org/)
+-----
+# this is a comment
+OPTION: value
+-----
-- cgmanager for cgroup management
+Blank lines in those files are ignored, and lines starting with a `#`
+character are treated as comments and are also ignored.
-- lxcfs to provive containerized /proc file system
+It is possible to add low-level, LXC style configuration directly, for
+example:
-- apparmor
+----
+lxc.init_cmd: /sbin/my_own_init
+----
-- CRIU: for live migration (planned)
+or
-- We use latest available kernels (4.4.X)
+----
+lxc.init_cmd = /sbin/my_own_init
+----
-- Image based deployment (templates)
+The settings are passed directly to the LXC low-level tools.
-- Container setup from host (Network, DNS, Storage, ...)
+
+[[pct_snapshots]]
+Snapshots
+~~~~~~~~~
+
+When you create a snapshot, `pct` stores the configuration at snapshot
+time into a separate snapshot section within the same configuration
+file. For example, after creating a snapshot called ``testsnapshot'',
+your configuration file will look like this:
+
+.Container configuration with snapshot
+----
+memory: 512
+swap: 512
+parent: testsnaphot
+...
+
+[testsnaphot]
+memory: 512
+swap: 512
+snaptime: 1457170803
+...
+----
+
+There are a few snapshot related properties like `parent` and
+`snaptime`. The `parent` property is used to store the parent/child
+relationship between snapshots. `snaptime` is the snapshot creation
+time stamp (Unix epoch).
+
+
+[[pct_options]]
+Options
+~~~~~~~
+
+include::pct.conf.5-opts.adoc[]
+
+
+Locks
+-----
+
+Container migrations, snapshots and backups (`vzdump`) set a lock to
+prevent incompatible concurrent actions on the affected container. Sometimes
+you need to remove such a lock manually (e.g., after a power failure).
+
+----
+# pct unlock <CTID>
+----
+
+CAUTION: Only do this if you are sure the action which set the lock is
+no longer running.
ifdef::manvolnum[]
+
+Files
+------
+
+`/etc/pve/lxc/<CTID>.conf`::
+
+Configuration file for the container '<CTID>'.
+
+
include::pve-copyright.adoc[]
endif::manvolnum[]
projects / pve-docs.git / blobdiff