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0c6b782f | 1 | ifdef::manvolnum[] |
b2f242ab | 2 | pct(1) |
7e2fdb3d | 3 | ====== |
38fd0958 | 4 | include::attributes.txt[] |
5f09af76 DM |
5 | :pve-toplevel: |
6 | ||
0c6b782f DM |
7 | NAME |
8 | ---- | |
9 | ||
10 | pct - Tool to manage Linux Containers (LXC) on Proxmox VE | |
11 | ||
12 | ||
49a5e11c | 13 | SYNOPSIS |
0c6b782f DM |
14 | -------- |
15 | ||
16 | include::pct.1-synopsis.adoc[] | |
17 | ||
18 | DESCRIPTION | |
19 | ----------- | |
20 | endif::manvolnum[] | |
21 | ||
22 | ifndef::manvolnum[] | |
23 | Proxmox Container Toolkit | |
24 | ========================= | |
38fd0958 | 25 | include::attributes.txt[] |
0c6b782f | 26 | endif::manvolnum[] |
5f09af76 DM |
27 | ifdef::wiki[] |
28 | :pve-toplevel: | |
cb84ed18 | 29 | :title: Linux Container |
5f09af76 | 30 | endif::wiki[] |
4a2ae9ed DM |
31 | |
32 | Containers are a lightweight alternative to fully virtualized | |
33 | VMs. Instead of emulating a complete Operating System (OS), containers | |
34 | simply use the OS of the host they run on. This implies that all | |
35 | containers use the same kernel, and that they can access resources | |
36 | from the host directly. | |
37 | ||
38 | This is great because containers do not waste CPU power nor memory due | |
39 | to kernel emulation. Container run-time costs are close to zero and | |
40 | usually negligible. But there are also some drawbacks you need to | |
41 | consider: | |
42 | ||
43 | * You can only run Linux based OS inside containers, i.e. it is not | |
a8e99754 | 44 | possible to run FreeBSD or MS Windows inside. |
4a2ae9ed | 45 | |
a8e99754 | 46 | * For security reasons, access to host resources needs to be |
4a2ae9ed | 47 | restricted. This is done with AppArmor, SecComp filters and other |
a8e99754 | 48 | kernel features. Be prepared that some syscalls are not allowed |
4a2ae9ed DM |
49 | inside containers. |
50 | ||
51 | {pve} uses https://linuxcontainers.org/[LXC] as underlying container | |
52 | technology. We consider LXC as low-level library, which provides | |
a8e99754 | 53 | countless options. It would be too difficult to use those tools |
4a2ae9ed DM |
54 | directly. Instead, we provide a small wrapper called `pct`, the |
55 | "Proxmox Container Toolkit". | |
56 | ||
a8e99754 | 57 | The toolkit is tightly coupled with {pve}. That means that it is aware |
4a2ae9ed DM |
58 | of the cluster setup, and it can use the same network and storage |
59 | resources as fully virtualized VMs. You can even use the {pve} | |
60 | firewall, or manage containers using the HA framework. | |
61 | ||
62 | Our primary goal is to offer an environment as one would get from a | |
63 | VM, but without the additional overhead. We call this "System | |
64 | Containers". | |
65 | ||
99d2e25b | 66 | NOTE: If you want to run micro-containers (with docker, rkt, ...), it |
70a42028 | 67 | is best to run them inside a VM. |
4a2ae9ed DM |
68 | |
69 | ||
70 | Security Considerations | |
71 | ----------------------- | |
72 | ||
73 | Containers use the same kernel as the host, so there is a big attack | |
74 | surface for malicious users. You should consider this fact if you | |
75 | provide containers to totally untrusted people. In general, fully | |
a8e99754 | 76 | virtualized VMs provide better isolation. |
4a2ae9ed DM |
77 | |
78 | The good news is that LXC uses many kernel security features like | |
79 | AppArmor, CGroups and PID and user namespaces, which makes containers | |
80 | usage quite secure. We distinguish two types of containers: | |
81 | ||
5eba0743 FG |
82 | |
83 | Privileged Containers | |
4a2ae9ed DM |
84 | ~~~~~~~~~~~~~~~~~~~~~ |
85 | ||
86 | Security is done by dropping capabilities, using mandatory access | |
87 | control (AppArmor), SecComp filters and namespaces. The LXC team | |
88 | considers this kind of container as unsafe, and they will not consider | |
89 | new container escape exploits to be security issues worthy of a CVE | |
90 | and quick fix. So you should use this kind of containers only inside a | |
91 | trusted environment, or when no untrusted task is running as root in | |
92 | the container. | |
93 | ||
5eba0743 FG |
94 | |
95 | Unprivileged Containers | |
4a2ae9ed DM |
96 | ~~~~~~~~~~~~~~~~~~~~~~~ |
97 | ||
a8e99754 | 98 | This kind of containers use a new kernel feature called user |
5eba0743 | 99 | namespaces. The root UID 0 inside the container is mapped to an |
4a2ae9ed DM |
100 | unprivileged user outside the container. This means that most security |
101 | issues (container escape, resource abuse, ...) in those containers | |
102 | will affect a random unprivileged user, and so would be a generic | |
a8e99754 | 103 | kernel security bug rather than an LXC issue. The LXC team thinks |
4a2ae9ed DM |
104 | unprivileged containers are safe by design. |
105 | ||
7fc230db DM |
106 | |
107 | Configuration | |
108 | ------------- | |
109 | ||
8c1189b6 FG |
110 | The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, |
111 | where `<CTID>` is the numeric ID of the given container. Like all | |
112 | other files stored inside `/etc/pve/`, they get automatically | |
166e63d6 FG |
113 | replicated to all other cluster nodes. |
114 | ||
115 | NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be | |
116 | unique cluster wide. | |
7fc230db | 117 | |
105bc8f1 DM |
118 | .Example Container Configuration |
119 | ---- | |
120 | ostype: debian | |
121 | arch: amd64 | |
122 | hostname: www | |
123 | memory: 512 | |
124 | swap: 512 | |
125 | net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth | |
126 | rootfs: local:107/vm-107-disk-1.raw,size=7G | |
127 | ---- | |
128 | ||
7fc230db | 129 | Those configuration files are simple text files, and you can edit them |
8c1189b6 | 130 | using a normal text editor (`vi`, `nano`, ...). This is sometimes |
55fb2a21 DM |
131 | useful to do small corrections, but keep in mind that you need to |
132 | restart the container to apply such changes. | |
133 | ||
8c1189b6 | 134 | For that reason, it is usually better to use the `pct` command to |
55fb2a21 DM |
135 | generate and modify those files, or do the whole thing using the GUI. |
136 | Our toolkit is smart enough to instantaneously apply most changes to | |
105bc8f1 DM |
137 | running containers. This feature is called "hot plug", and there is no |
138 | need to restart the container in that case. | |
7fc230db | 139 | |
5eba0743 | 140 | |
7fc230db DM |
141 | File Format |
142 | ~~~~~~~~~~~ | |
143 | ||
144 | Container configuration files use a simple colon separated key/value | |
145 | format. Each line has the following format: | |
146 | ||
083adc34 FG |
147 | ----- |
148 | # this is a comment | |
149 | OPTION: value | |
150 | ----- | |
7fc230db | 151 | |
8c1189b6 | 152 | Blank lines in those files are ignored, and lines starting with a `#` |
7fc230db DM |
153 | character are treated as comments and are also ignored. |
154 | ||
155 | It is possible to add low-level, LXC style configuration directly, for | |
156 | example: | |
157 | ||
158 | lxc.init_cmd: /sbin/my_own_init | |
159 | ||
160 | or | |
161 | ||
162 | lxc.init_cmd = /sbin/my_own_init | |
163 | ||
164 | Those settings are directly passed to the LXC low-level tools. | |
165 | ||
5eba0743 | 166 | |
105bc8f1 DM |
167 | Snapshots |
168 | ~~~~~~~~~ | |
169 | ||
8c1189b6 | 170 | When you create a snapshot, `pct` stores the configuration at snapshot |
105bc8f1 | 171 | time into a separate snapshot section within the same configuration |
8c1189b6 | 172 | file. For example, after creating a snapshot called ``testsnapshot'', |
105bc8f1 DM |
173 | your configuration file will look like this: |
174 | ||
5eba0743 | 175 | .Container configuration with snapshot |
105bc8f1 DM |
176 | ---- |
177 | memory: 512 | |
178 | swap: 512 | |
179 | parent: testsnaphot | |
180 | ... | |
181 | ||
182 | [testsnaphot] | |
183 | memory: 512 | |
184 | swap: 512 | |
185 | snaptime: 1457170803 | |
186 | ... | |
187 | ---- | |
188 | ||
8c1189b6 FG |
189 | There are a few snapshot related properties like `parent` and |
190 | `snaptime`. The `parent` property is used to store the parent/child | |
191 | relationship between snapshots. `snaptime` is the snapshot creation | |
192 | time stamp (Unix epoch). | |
193 | ||
7fc230db | 194 | |
3f13c1c3 DM |
195 | Guest Operating System Configuration |
196 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
197 | ||
198 | We normally try to detect the operating system type inside the | |
199 | container, and then modify some files inside the container to make | |
200 | them work as expected. Here is a short list of things we do at | |
201 | container startup: | |
202 | ||
203 | set /etc/hostname:: to set the container name | |
204 | ||
a8e99754 | 205 | modify /etc/hosts:: to allow lookup of the local hostname |
3f13c1c3 DM |
206 | |
207 | network setup:: pass the complete network setup to the container | |
208 | ||
209 | configure DNS:: pass information about DNS servers | |
210 | ||
a8e99754 | 211 | adapt the init system:: for example, fix the number of spawned getty processes |
3f13c1c3 DM |
212 | |
213 | set the root password:: when creating a new container | |
214 | ||
215 | rewrite ssh_host_keys:: so that each container has unique keys | |
216 | ||
a8e99754 | 217 | randomize crontab:: so that cron does not start at the same time on all containers |
3f13c1c3 | 218 | |
25535d34 WB |
219 | Changes made by {PVE} are enclosed by comment markers: |
220 | ||
37638f59 DM |
221 | ---- |
222 | # --- BEGIN PVE --- | |
223 | <data> | |
224 | # --- END PVE --- | |
225 | ---- | |
25535d34 | 226 | |
37638f59 DM |
227 | Those markers will be inserted at a reasonable location in the |
228 | file. If such a section already exists, it will be updated in place | |
229 | and will not be moved. | |
25535d34 | 230 | |
37638f59 DM |
231 | Modification of a file can be prevented by adding a `.pve-ignore.` |
232 | file for it. For instance, if the file `/etc/.pve-ignore.hosts` | |
233 | exists then the `/etc/hosts` file will not be touched. This can be a | |
234 | simple empty file creatd via: | |
25535d34 WB |
235 | |
236 | # touch /etc/.pve-ignore.hosts | |
237 | ||
37638f59 DM |
238 | Most modifications are OS dependent, so they differ between different |
239 | distributions and versions. You can completely disable modifications | |
8c1189b6 | 240 | by manually setting the `ostype` to `unmanaged`. |
3f13c1c3 DM |
241 | |
242 | OS type detection is done by testing for certain files inside the | |
243 | container: | |
244 | ||
8c1189b6 | 245 | Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`) |
3f13c1c3 DM |
246 | |
247 | Debian:: test /etc/debian_version | |
248 | ||
249 | Fedora:: test /etc/fedora-release | |
250 | ||
251 | RedHat or CentOS:: test /etc/redhat-release | |
252 | ||
253 | ArchLinux:: test /etc/arch-release | |
254 | ||
255 | Alpine:: test /etc/alpine-release | |
256 | ||
c617d721 WB |
257 | Gentoo:: test /etc/gentoo-release |
258 | ||
8c1189b6 | 259 | NOTE: Container start fails if the configured `ostype` differs from the auto |
3f13c1c3 DM |
260 | detected type. |
261 | ||
5eba0743 | 262 | |
a7f36905 DM |
263 | Options |
264 | ~~~~~~~ | |
265 | ||
266 | include::pct.conf.5-opts.adoc[] | |
267 | ||
d61bab51 DM |
268 | |
269 | Container Images | |
270 | ---------------- | |
271 | ||
8c1189b6 FG |
272 | Container images, sometimes also referred to as ``templates'' or |
273 | ``appliances'', are `tar` archives which contain everything to run a | |
d61bab51 | 274 | container. You can think of it as a tidy container backup. Like most |
8c1189b6 | 275 | modern container toolkits, `pct` uses those images when you create a |
d61bab51 DM |
276 | new container, for example: |
277 | ||
278 | pct create 999 local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
279 | ||
26ca7ff5 | 280 | {pve} itself ships a set of basic templates for most common |
8c1189b6 | 281 | operating systems, and you can download them using the `pveam` (short |
d61bab51 DM |
282 | for {pve} Appliance Manager) command line utility. You can also |
283 | download https://www.turnkeylinux.org/[TurnKey Linux] containers using | |
284 | that tool (or the graphical user interface). | |
285 | ||
3a6fa247 DM |
286 | Our image repositories contain a list of available images, and there |
287 | is a cron job run each day to download that list. You can trigger that | |
288 | update manually with: | |
289 | ||
290 | pveam update | |
291 | ||
292 | After that you can view the list of available images using: | |
293 | ||
294 | pveam available | |
295 | ||
8c1189b6 FG |
296 | You can restrict this large list by specifying the `section` you are |
297 | interested in, for example basic `system` images: | |
3a6fa247 DM |
298 | |
299 | .List available system images | |
300 | ---- | |
301 | # pveam available --section system | |
302 | system archlinux-base_2015-24-29-1_x86_64.tar.gz | |
303 | system centos-7-default_20160205_amd64.tar.xz | |
304 | system debian-6.0-standard_6.0-7_amd64.tar.gz | |
305 | system debian-7.0-standard_7.0-3_amd64.tar.gz | |
306 | system debian-8.0-standard_8.0-1_amd64.tar.gz | |
307 | system ubuntu-12.04-standard_12.04-1_amd64.tar.gz | |
308 | system ubuntu-14.04-standard_14.04-1_amd64.tar.gz | |
309 | system ubuntu-15.04-standard_15.04-1_amd64.tar.gz | |
310 | system ubuntu-15.10-standard_15.10-1_amd64.tar.gz | |
311 | ---- | |
312 | ||
a8e99754 | 313 | Before you can use such a template, you need to download them into one |
8c1189b6 | 314 | of your storages. You can simply use storage `local` for that |
3a6fa247 DM |
315 | purpose. For clustered installations, it is preferred to use a shared |
316 | storage so that all nodes can access those images. | |
317 | ||
318 | pveam download local debian-8.0-standard_8.0-1_amd64.tar.gz | |
319 | ||
24f73a63 | 320 | You are now ready to create containers using that image, and you can |
8c1189b6 | 321 | list all downloaded images on storage `local` with: |
24f73a63 DM |
322 | |
323 | ---- | |
324 | # pveam list local | |
325 | local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz 190.20MB | |
326 | ---- | |
327 | ||
a8e99754 | 328 | The above command shows you the full {pve} volume identifiers. They include |
24f73a63 | 329 | the storage name, and most other {pve} commands can use them. For |
5eba0743 | 330 | example you can delete that image later with: |
24f73a63 DM |
331 | |
332 | pveam remove local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
3a6fa247 | 333 | |
d61bab51 | 334 | |
70a42028 DM |
335 | Container Storage |
336 | ----------------- | |
337 | ||
338 | Traditional containers use a very simple storage model, only allowing | |
339 | a single mount point, the root file system. This was further | |
8c1189b6 FG |
340 | restricted to specific file system types like `ext4` and `nfs`. |
341 | Additional mounts are often done by user provided scripts. This turned | |
a8e99754 | 342 | out to be complex and error prone, so we try to avoid that now. |
70a42028 DM |
343 | |
344 | Our new LXC based container model is more flexible regarding | |
345 | storage. First, you can have more than a single mount point. This | |
346 | allows you to choose a suitable storage for each application. For | |
347 | example, you can use a relatively slow (and thus cheap) storage for | |
348 | the container root file system. Then you can use a second mount point | |
349 | to mount a very fast, distributed storage for your database | |
350 | application. | |
351 | ||
352 | The second big improvement is that you can use any storage type | |
353 | supported by the {pve} storage library. That means that you can store | |
8c1189b6 FG |
354 | your containers on local `lvmthin` or `zfs`, shared `iSCSI` storage, |
355 | or even on distributed storage systems like `ceph`. It also enables us | |
356 | to use advanced storage features like snapshots and clones. `vzdump` | |
a8e99754 | 357 | can also use the snapshot feature to provide consistent container |
70a42028 DM |
358 | backups. |
359 | ||
360 | Last but not least, you can also mount local devices directly, or | |
361 | mount local directories using bind mounts. That way you can access | |
362 | local storage inside containers with zero overhead. Such bind mounts | |
a8e99754 | 363 | also provide an easy way to share data between different containers. |
70a42028 | 364 | |
eeecce95 | 365 | |
9e44e493 DM |
366 | Mount Points |
367 | ~~~~~~~~~~~~ | |
eeecce95 | 368 | |
01639994 FG |
369 | The root mount point is configured with the `rootfs` property, and you can |
370 | configure up to 10 additional mount points. The corresponding options | |
371 | are called `mp0` to `mp9`, and they can contain the following setting: | |
372 | ||
373 | include::pct-mountpoint-opts.adoc[] | |
374 | ||
9e44e493 DM |
375 | Currently there are basically three types of mount points: storage backed |
376 | mount points, bind mounts and device mounts. | |
377 | ||
5eba0743 | 378 | .Typical container `rootfs` configuration |
4c3b5c77 DM |
379 | ---- |
380 | rootfs: thin1:base-100-disk-1,size=8G | |
381 | ---- | |
382 | ||
383 | ||
5eba0743 | 384 | Storage Backed Mount Points |
4c3b5c77 | 385 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
01639994 | 386 | |
9e44e493 | 387 | Storage backed mount points are managed by the {pve} storage subsystem and come |
eeecce95 WB |
388 | in three different flavors: |
389 | ||
5eba0743 | 390 | - Image based: these are raw images containing a single ext4 formatted file |
eeecce95 | 391 | system. |
5eba0743 | 392 | - ZFS subvolumes: these are technically bind mounts, but with managed storage, |
eeecce95 WB |
393 | and thus allow resizing and snapshotting. |
394 | - Directories: passing `size=0` triggers a special case where instead of a raw | |
395 | image a directory is created. | |
396 | ||
4c3b5c77 | 397 | |
5eba0743 | 398 | Bind Mount Points |
4c3b5c77 | 399 | ^^^^^^^^^^^^^^^^^ |
01639994 | 400 | |
9baca183 FG |
401 | Bind mounts allow you to access arbitrary directories from your Proxmox VE host |
402 | inside a container. Some potential use cases are: | |
403 | ||
404 | - Accessing your home directory in the guest | |
405 | - Accessing an USB device directory in the guest | |
acccc49b | 406 | - Accessing an NFS mount from the host in the guest |
9baca183 | 407 | |
eeecce95 | 408 | Bind mounts are considered to not be managed by the storage subsystem, so you |
9baca183 | 409 | cannot make snapshots or deal with quotas from inside the container. With |
eeecce95 | 410 | unprivileged containers you might run into permission problems caused by the |
9baca183 FG |
411 | user mapping and cannot use ACLs. |
412 | ||
8c1189b6 | 413 | NOTE: The contents of bind mount points are not backed up when using `vzdump`. |
eeecce95 | 414 | |
6b707f2c FG |
415 | WARNING: For security reasons, bind mounts should only be established |
416 | using source directories especially reserved for this purpose, e.g., a | |
417 | directory hierarchy under `/mnt/bindmounts`. Never bind mount system | |
418 | directories like `/`, `/var` or `/etc` into a container - this poses a | |
9baca183 FG |
419 | great security risk. |
420 | ||
421 | NOTE: The bind mount source path must not contain any symlinks. | |
422 | ||
423 | For example, to make the directory `/mnt/bindmounts/shared` accessible in the | |
424 | container with ID `100` under the path `/shared`, use a configuration line like | |
8c1189b6 FG |
425 | `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`. |
426 | Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to | |
9baca183 | 427 | achieve the same result. |
6b707f2c | 428 | |
4c3b5c77 | 429 | |
5eba0743 | 430 | Device Mount Points |
4c3b5c77 | 431 | ^^^^^^^^^^^^^^^^^^^ |
fe154a4f | 432 | |
7432d78e FG |
433 | Device mount points allow to mount block devices of the host directly into the |
434 | container. Similar to bind mounts, device mounts are not managed by {PVE}'s | |
435 | storage subsystem, but the `quota` and `acl` options will be honored. | |
436 | ||
437 | NOTE: Device mount points should only be used under special circumstances. In | |
438 | most cases a storage backed mount point offers the same performance and a lot | |
439 | more features. | |
440 | ||
8c1189b6 | 441 | NOTE: The contents of device mount points are not backed up when using `vzdump`. |
01639994 | 442 | |
4c3b5c77 | 443 | |
5eba0743 | 444 | FUSE Mounts |
4c3b5c77 | 445 | ~~~~~~~~~~~ |
01639994 FG |
446 | |
447 | WARNING: Because of existing issues in the Linux kernel's freezer | |
448 | subsystem the usage of FUSE mounts inside a container is strongly | |
449 | advised against, as containers need to be frozen for suspend or | |
450 | snapshot mode backups. | |
fe154a4f | 451 | |
01639994 FG |
452 | If FUSE mounts cannot be replaced by other mounting mechanisms or storage |
453 | technologies, it is possible to establish the FUSE mount on the Proxmox host | |
454 | and use a bind mount point to make it accessible inside the container. | |
455 | ||
01639994 | 456 | |
5eba0743 | 457 | Using Quotas Inside Containers |
04c569f6 | 458 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
d6ed3622 | 459 | |
9e44e493 DM |
460 | Quotas allow to set limits inside a container for the amount of disk |
461 | space that each user can use. This only works on ext4 image based | |
462 | storage types and currently does not work with unprivileged | |
463 | containers. | |
d6ed3622 | 464 | |
9e44e493 DM |
465 | Activating the `quota` option causes the following mount options to be |
466 | used for a mount point: | |
467 | `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0` | |
d6ed3622 | 468 | |
9e44e493 DM |
469 | This allows quotas to be used like you would on any other system. You |
470 | can initialize the `/aquota.user` and `/aquota.group` files by running | |
d6ed3622 | 471 | |
9e44e493 DM |
472 | ---- |
473 | quotacheck -cmug / | |
474 | quotaon / | |
475 | ---- | |
d6ed3622 | 476 | |
166e63d6 FG |
477 | and edit the quotas via the `edquota` command. Refer to the documentation |
478 | of the distribution running inside the container for details. | |
479 | ||
9e44e493 DM |
480 | NOTE: You need to run the above commands for every mount point by passing |
481 | the mount point's path instead of just `/`. | |
482 | ||
d6ed3622 | 483 | |
5eba0743 | 484 | Using ACLs Inside Containers |
04c569f6 | 485 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
6c60aebf | 486 | |
5eba0743 | 487 | The standard Posix **A**ccess **C**ontrol **L**ists are also available inside containers. |
6c60aebf EK |
488 | ACLs allow you to set more detailed file ownership than the traditional user/ |
489 | group/others model. | |
d6ed3622 | 490 | |
04c569f6 DM |
491 | |
492 | Container Network | |
493 | ----------------- | |
494 | ||
bac8c385 | 495 | You can configure up to 10 network interfaces for a single |
8c1189b6 | 496 | container. The corresponding options are called `net0` to `net9`, and |
bac8c385 DM |
497 | they can contain the following setting: |
498 | ||
499 | include::pct-network-opts.adoc[] | |
04c569f6 DM |
500 | |
501 | ||
51e33128 FG |
502 | Backup and Restore |
503 | ------------------ | |
504 | ||
5eba0743 | 505 | |
2175e37b FG |
506 | Container Backup |
507 | ~~~~~~~~~~~~~~~~ | |
508 | ||
8c1189b6 FG |
509 | It is possible to use the `vzdump` tool for container backup. Please |
510 | refer to the `vzdump` manual page for details. | |
511 | ||
51e33128 | 512 | |
2175e37b FG |
513 | Restoring Container Backups |
514 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
515 | ||
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516 | Restoring container backups made with `vzdump` is possible using the |
517 | `pct restore` command. By default, `pct restore` will attempt to restore as much | |
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518 | of the backed up container configuration as possible. It is possible to override |
519 | the backed up configuration by manually setting container options on the command | |
8c1189b6 | 520 | line (see the `pct` manual page for details). |
2175e37b | 521 | |
8c1189b6 | 522 | NOTE: `pvesm extractconfig` can be used to view the backed up configuration |
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523 | contained in a vzdump archive. |
524 | ||
525 | There are two basic restore modes, only differing by their handling of mount | |
526 | points: | |
527 | ||
4c3b5c77 | 528 | |
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529 | ``Simple'' Restore Mode |
530 | ^^^^^^^^^^^^^^^^^^^^^^^ | |
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531 | |
532 | If neither the `rootfs` parameter nor any of the optional `mpX` parameters | |
533 | are explicitly set, the mount point configuration from the backed up | |
534 | configuration file is restored using the following steps: | |
535 | ||
536 | . Extract mount points and their options from backup | |
537 | . Create volumes for storage backed mount points (on storage provided with the | |
538 | `storage` parameter, or default local storage if unset) | |
539 | . Extract files from backup archive | |
540 | . Add bind and device mount points to restored configuration (limited to root user) | |
541 | ||
542 | NOTE: Since bind and device mount points are never backed up, no files are | |
543 | restored in the last step, but only the configuration options. The assumption | |
544 | is that such mount points are either backed up with another mechanism (e.g., | |
545 | NFS space that is bind mounted into many containers), or not intended to be | |
546 | backed up at all. | |
547 | ||
548 | This simple mode is also used by the container restore operations in the web | |
549 | interface. | |
550 | ||
4c3b5c77 | 551 | |
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552 | ``Advanced'' Restore Mode |
553 | ^^^^^^^^^^^^^^^^^^^^^^^^^ | |
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554 | |
555 | By setting the `rootfs` parameter (and optionally, any combination of `mpX` | |
8c1189b6 | 556 | parameters), the `pct restore` command is automatically switched into an |
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557 | advanced mode. This advanced mode completely ignores the `rootfs` and `mpX` |
558 | configuration options contained in the backup archive, and instead only | |
559 | uses the options explicitly provided as parameters. | |
560 | ||
561 | This mode allows flexible configuration of mount point settings at restore time, | |
562 | for example: | |
563 | ||
564 | * Set target storages, volume sizes and other options for each mount point | |
565 | individually | |
566 | * Redistribute backed up files according to new mount point scheme | |
567 | * Restore to device and/or bind mount points (limited to root user) | |
568 | ||
51e33128 | 569 | |
8c1189b6 | 570 | Managing Containers with `pct` |
04c569f6 DM |
571 | ------------------------------ |
572 | ||
8c1189b6 | 573 | `pct` is the tool to manage Linux Containers on {pve}. You can create |
04c569f6 DM |
574 | and destroy containers, and control execution (start, stop, migrate, |
575 | ...). You can use pct to set parameters in the associated config file, | |
576 | like network configuration or memory limits. | |
577 | ||
5eba0743 | 578 | |
04c569f6 DM |
579 | CLI Usage Examples |
580 | ~~~~~~~~~~~~~~~~~~ | |
581 | ||
582 | Create a container based on a Debian template (provided you have | |
5eba0743 | 583 | already downloaded the template via the web interface) |
04c569f6 DM |
584 | |
585 | pct create 100 /var/lib/vz/template/cache/debian-8.0-standard_8.0-1_amd64.tar.gz | |
586 | ||
587 | Start container 100 | |
588 | ||
589 | pct start 100 | |
590 | ||
591 | Start a login session via getty | |
592 | ||
593 | pct console 100 | |
594 | ||
595 | Enter the LXC namespace and run a shell as root user | |
596 | ||
597 | pct enter 100 | |
598 | ||
599 | Display the configuration | |
600 | ||
601 | pct config 100 | |
602 | ||
8c1189b6 | 603 | Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, |
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604 | set the address and gateway, while it's running |
605 | ||
606 | pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1 | |
607 | ||
608 | Reduce the memory of the container to 512MB | |
609 | ||
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610 | pct set 100 -memory 512 |
611 | ||
04c569f6 | 612 | |
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613 | Obtaining Debugging Logs |
614 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
615 | ||
616 | In case `pct start` is unable to start a specific container, it might be | |
617 | helpful to collect debugging output by running `lxc-start` (replace `ID` with | |
618 | the container's ID): | |
619 | ||
620 | lxc-start -n ID -F -l DEBUG -o /tmp/lxc-ID.log | |
621 | ||
622 | 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. | |
623 | ||
624 | The collected debug log is written to `/tmp/lxc-ID.log`. | |
625 | ||
626 | NOTE: If you have changed the container's configuration since the last start | |
627 | attempt with `pct start`, you need to run `pct start` at least once to also | |
628 | update the configuration used by `lxc-start`. | |
629 | ||
630 | ||
04c569f6 DM |
631 | Files |
632 | ------ | |
633 | ||
8c1189b6 | 634 | `/etc/pve/lxc/<CTID>.conf`:: |
04c569f6 DM |
635 | |
636 | Configuration file for the container '<CTID>'. | |
637 | ||
638 | ||
0c6b782f DM |
639 | Container Advantages |
640 | -------------------- | |
641 | ||
8c1189b6 | 642 | * Simple, and fully integrated into {pve}. Setup looks similar to a normal |
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643 | VM setup. |
644 | ||
8c1189b6 | 645 | ** Storage (ZFS, LVM, NFS, Ceph, ...) |
0c6b782f | 646 | |
8c1189b6 | 647 | ** Network |
0c6b782f | 648 | |
8c1189b6 | 649 | ** Authentication |
0c6b782f | 650 | |
8c1189b6 | 651 | ** Cluster |
0c6b782f | 652 | |
8c1189b6 | 653 | * Fast: minimal overhead, as fast as bare metal |
0c6b782f | 654 | |
8c1189b6 | 655 | * High density (perfect for idle workloads) |
0c6b782f | 656 | |
8c1189b6 | 657 | * REST API |
0c6b782f | 658 | |
8c1189b6 | 659 | * Direct hardware access |
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660 | |
661 | ||
662 | Technology Overview | |
663 | ------------------- | |
664 | ||
80b5819d | 665 | * Integrated into {pve} graphical user interface (GUI) |
0c6b782f | 666 | |
80b5819d | 667 | * LXC (https://linuxcontainers.org/) |
0c6b782f | 668 | |
80b5819d | 669 | * lxcfs to provide containerized /proc file system |
0c6b782f | 670 | |
80b5819d | 671 | * AppArmor |
0c6b782f | 672 | |
80b5819d | 673 | * CRIU: for live migration (planned) |
0c6b782f | 674 | |
80b5819d | 675 | * We use latest available kernels (4.4.X) |
0c6b782f | 676 | |
80b5819d | 677 | * Image based deployment (templates) |
0c6b782f | 678 | |
80b5819d | 679 | * Container setup from host (network, DNS, storage, ...) |
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680 | |
681 | ||
682 | ifdef::manvolnum[] | |
683 | include::pve-copyright.adoc[] | |
684 | endif::manvolnum[] | |
685 | ||
686 | ||
687 | ||
688 | ||
689 | ||
690 | ||
691 |