X-Git-Url: https://git.proxmox.com/?p=pve-docs.git;a=blobdiff_plain;f=pct.adoc;h=9983ba8e03544ed2823100dce28b220438b968c2;hp=95856da31bc5196ff32af9d787d2abe5f12bb3d9;hb=acccc49b99ab96c0c69d6e5b0f8357d7edefc720;hpb=0585f29ac4ed08d13d073ccc77a344ec0e951d43 diff --git a/pct.adoc b/pct.adoc index 95856da..9983ba8 100644 --- a/pct.adoc +++ b/pct.adoc @@ -59,7 +59,7 @@ 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, rct, ...), it +NOTE: If you want to run micro-containers (with docker, rkt, ...), it is best to run them inside a VM. @@ -205,9 +205,28 @@ rewrite ssh_host_keys:: so that each container has unique keys randomize crontab:: so that cron does not start at the same time on all containers -The above task depends on the OS type, so the implementation is different -for each OS type. You can also disable any modifications by manually -setting the 'ostype' to 'unmanaged'. +Changes made by {PVE} are enclosed by comment markers: + +---- +# --- BEGIN PVE --- + +# --- END PVE --- +---- + +Those markers will be inserted at a reasonable location in the +file. If such a section already exists, it will be updated in place +and will not be moved. + +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: + + # 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'. OS type detection is done by testing for certain files inside the container: @@ -224,9 +243,16 @@ ArchLinux:: test /etc/arch-release Alpine:: test /etc/alpine-release +Gentoo:: test /etc/gentoo-release + NOTE: Container start fails if the configured 'ostype' differs from the auto detected type. +Options +~~~~~~~ + +include::pct.conf.5-opts.adoc[] + Container Images ---------------- @@ -328,10 +354,24 @@ also provide an easy way to share data between different containers. Mount Points ~~~~~~~~~~~~ -Beside the root directory the container can also have additional 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: + +include::pct-mountpoint-opts.adoc[] + Currently there are basically three types of mount points: storage backed mount points, bind mounts and device mounts. +.Typical Container `rootfs` configuration +---- +rootfs: thin1:base-100-disk-1,size=8G +---- + + +Storage backed mount points +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + Storage backed mount points are managed by the {pve} storage subsystem and come in three different flavors: @@ -342,32 +382,65 @@ in three different flavors: - Directories: passing `size=0` triggers a special case where instead of a raw image a directory is created. + +Bind mount points +^^^^^^^^^^^^^^^^^ + +Bind mounts allow you to access arbitrary directories from your Proxmox VE host +inside a container. Some potential use cases are: + +- Accessing your home directory in the guest +- Accessing an USB device directory in the guest +- Accessing an NFS mount from the host in the guest + Bind mounts are considered to not be managed by the storage subsystem, so you -cannot make snapshots or deal with quotas from inside the container, and with +cannot make snapshots or deal with quotas from inside the container. With unprivileged containers you might run into permission problems caused by the -user mapping, and cannot use ACLs from inside an unprivileged container. +user mapping and cannot use ACLs. + +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 +directory hierarchy under `/mnt/bindmounts`. Never bind mount system +directories like `/`, `/var` or `/etc` into a container - this poses a +great security risk. + +NOTE: The bind mount source path must not contain any symlinks. + +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 +achieve the same result. + + +Device mount points +^^^^^^^^^^^^^^^^^^^ -Similarly device mounts are not managed by the storage, but for these the -`quota` and `acl` options will be honored. +Device mount points allow to mount block devices of the host directly into the +container. Similar to bind mounts, device mounts are not managed by {PVE}'s +storage subsystem, but the `quota` and `acl` options will be honored. + +NOTE: Device mount points should only be used under special circumstances. In +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'. + + +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. +snapshot mode backups. -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: +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. -include::pct-mountpoint-opts.adoc[] - -.Typical Container 'rootfs' configuration ----- -rootfs: thin1:base-100-disk-1,size=8G ----- Using quotas inside containers ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -414,6 +487,72 @@ they can contain the following setting: include::pct-network-opts.adoc[] +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. + +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 +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). + +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 +^^^^^^^^^^^^^^^^^^^^^ + +If neither the `rootfs` parameter nor any of the optional `mpX` parameters +are explicitly set, the mount point configuration from the backed up +configuration file is restored using the following steps: + +. Extract mount points and their options from backup +. Create volumes for storage backed mount points (on storage provided with the +`storage` parameter, or default local storage if unset) +. Extract files from backup archive +. Add bind and device mount points to restored configuration (limited to root user) + +NOTE: Since bind and device mount points are never backed up, no files are +restored in the last step, but only the configuration options. The assumption +is that such mount points are either backed up with another mechanism (e.g., +NFS space that is bind mounted into many containers), or not intended to be +backed up at all. + +This simple mode is also used by the container restore operations in the web +interface. + + +"Advanced" restore mode +^^^^^^^^^^^^^^^^^^^^^^^ + +By setting the `rootfs` parameter (and optionally, any combination of `mpX` +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. + +This mode allows flexible configuration of mount point settings at restore time, +for example: + +* Set target storages, volume sizes and other options for each mount point +individually +* Redistribute backed up files according to new mount point scheme +* Restore to device and/or bind mount points (limited to root user) + + Managing Containers with 'pct' ------------------------------