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80c0adcb | 1 | [[chapter_pct]] |
0c6b782f | 2 | ifdef::manvolnum[] |
b2f242ab | 3 | pct(1) |
7e2fdb3d | 4 | ====== |
38fd0958 | 5 | include::attributes.txt[] |
5f09af76 DM |
6 | :pve-toplevel: |
7 | ||
0c6b782f DM |
8 | NAME |
9 | ---- | |
10 | ||
11 | pct - Tool to manage Linux Containers (LXC) on Proxmox VE | |
12 | ||
13 | ||
49a5e11c | 14 | SYNOPSIS |
0c6b782f DM |
15 | -------- |
16 | ||
17 | include::pct.1-synopsis.adoc[] | |
18 | ||
19 | DESCRIPTION | |
20 | ----------- | |
21 | endif::manvolnum[] | |
22 | ||
23 | ifndef::manvolnum[] | |
24 | Proxmox Container Toolkit | |
25 | ========================= | |
38fd0958 | 26 | include::attributes.txt[] |
194d2f29 | 27 | :pve-toplevel: |
0c6b782f | 28 | endif::manvolnum[] |
5f09af76 | 29 | ifdef::wiki[] |
cb84ed18 | 30 | :title: Linux Container |
5f09af76 | 31 | endif::wiki[] |
4a2ae9ed DM |
32 | |
33 | Containers are a lightweight alternative to fully virtualized | |
34 | VMs. Instead of emulating a complete Operating System (OS), containers | |
35 | simply use the OS of the host they run on. This implies that all | |
36 | containers use the same kernel, and that they can access resources | |
37 | from the host directly. | |
38 | ||
39 | This is great because containers do not waste CPU power nor memory due | |
40 | to kernel emulation. Container run-time costs are close to zero and | |
41 | usually negligible. But there are also some drawbacks you need to | |
42 | consider: | |
43 | ||
44 | * You can only run Linux based OS inside containers, i.e. it is not | |
a8e99754 | 45 | possible to run FreeBSD or MS Windows inside. |
4a2ae9ed | 46 | |
a8e99754 | 47 | * For security reasons, access to host resources needs to be |
4a2ae9ed | 48 | restricted. This is done with AppArmor, SecComp filters and other |
a8e99754 | 49 | kernel features. Be prepared that some syscalls are not allowed |
4a2ae9ed DM |
50 | inside containers. |
51 | ||
52 | {pve} uses https://linuxcontainers.org/[LXC] as underlying container | |
53 | technology. We consider LXC as low-level library, which provides | |
a8e99754 | 54 | countless options. It would be too difficult to use those tools |
4a2ae9ed DM |
55 | directly. Instead, we provide a small wrapper called `pct`, the |
56 | "Proxmox Container Toolkit". | |
57 | ||
a8e99754 | 58 | The toolkit is tightly coupled with {pve}. That means that it is aware |
4a2ae9ed DM |
59 | of the cluster setup, and it can use the same network and storage |
60 | resources as fully virtualized VMs. You can even use the {pve} | |
61 | firewall, or manage containers using the HA framework. | |
62 | ||
63 | Our primary goal is to offer an environment as one would get from a | |
64 | VM, but without the additional overhead. We call this "System | |
65 | Containers". | |
66 | ||
99d2e25b | 67 | NOTE: If you want to run micro-containers (with docker, rkt, ...), it |
70a42028 | 68 | is best to run them inside a VM. |
4a2ae9ed DM |
69 | |
70 | ||
71 | Security Considerations | |
72 | ----------------------- | |
73 | ||
74 | Containers use the same kernel as the host, so there is a big attack | |
75 | surface for malicious users. You should consider this fact if you | |
76 | provide containers to totally untrusted people. In general, fully | |
a8e99754 | 77 | virtualized VMs provide better isolation. |
4a2ae9ed DM |
78 | |
79 | The good news is that LXC uses many kernel security features like | |
80 | AppArmor, CGroups and PID and user namespaces, which makes containers | |
81 | usage quite secure. We distinguish two types of containers: | |
82 | ||
5eba0743 FG |
83 | |
84 | Privileged Containers | |
4a2ae9ed DM |
85 | ~~~~~~~~~~~~~~~~~~~~~ |
86 | ||
87 | Security is done by dropping capabilities, using mandatory access | |
88 | control (AppArmor), SecComp filters and namespaces. The LXC team | |
89 | considers this kind of container as unsafe, and they will not consider | |
90 | new container escape exploits to be security issues worthy of a CVE | |
91 | and quick fix. So you should use this kind of containers only inside a | |
92 | trusted environment, or when no untrusted task is running as root in | |
93 | the container. | |
94 | ||
5eba0743 FG |
95 | |
96 | Unprivileged Containers | |
4a2ae9ed DM |
97 | ~~~~~~~~~~~~~~~~~~~~~~~ |
98 | ||
a8e99754 | 99 | This kind of containers use a new kernel feature called user |
5eba0743 | 100 | namespaces. The root UID 0 inside the container is mapped to an |
4a2ae9ed DM |
101 | unprivileged user outside the container. This means that most security |
102 | issues (container escape, resource abuse, ...) in those containers | |
103 | will affect a random unprivileged user, and so would be a generic | |
a8e99754 | 104 | kernel security bug rather than an LXC issue. The LXC team thinks |
4a2ae9ed DM |
105 | unprivileged containers are safe by design. |
106 | ||
3bd9d0cf | 107 | |
53e3cd6f DM |
108 | Guest Operating System Configuration |
109 | ------------------------------------ | |
110 | ||
111 | We normally try to detect the operating system type inside the | |
112 | container, and then modify some files inside the container to make | |
113 | them work as expected. Here is a short list of things we do at | |
114 | container startup: | |
115 | ||
116 | set /etc/hostname:: to set the container name | |
117 | ||
118 | modify /etc/hosts:: to allow lookup of the local hostname | |
119 | ||
120 | network setup:: pass the complete network setup to the container | |
121 | ||
122 | configure DNS:: pass information about DNS servers | |
123 | ||
124 | adapt the init system:: for example, fix the number of spawned getty processes | |
125 | ||
126 | set the root password:: when creating a new container | |
127 | ||
128 | rewrite ssh_host_keys:: so that each container has unique keys | |
129 | ||
130 | randomize crontab:: so that cron does not start at the same time on all containers | |
131 | ||
132 | Changes made by {PVE} are enclosed by comment markers: | |
133 | ||
134 | ---- | |
135 | # --- BEGIN PVE --- | |
136 | <data> | |
137 | # --- END PVE --- | |
138 | ---- | |
139 | ||
140 | Those markers will be inserted at a reasonable location in the | |
141 | file. If such a section already exists, it will be updated in place | |
142 | and will not be moved. | |
143 | ||
144 | Modification of a file can be prevented by adding a `.pve-ignore.` | |
145 | file for it. For instance, if the file `/etc/.pve-ignore.hosts` | |
146 | exists then the `/etc/hosts` file will not be touched. This can be a | |
147 | simple empty file creatd via: | |
148 | ||
149 | # touch /etc/.pve-ignore.hosts | |
150 | ||
151 | Most modifications are OS dependent, so they differ between different | |
152 | distributions and versions. You can completely disable modifications | |
153 | by manually setting the `ostype` to `unmanaged`. | |
154 | ||
155 | OS type detection is done by testing for certain files inside the | |
156 | container: | |
157 | ||
158 | Ubuntu:: inspect /etc/lsb-release (`DISTRIB_ID=Ubuntu`) | |
159 | ||
160 | Debian:: test /etc/debian_version | |
161 | ||
162 | Fedora:: test /etc/fedora-release | |
163 | ||
164 | RedHat or CentOS:: test /etc/redhat-release | |
165 | ||
166 | ArchLinux:: test /etc/arch-release | |
167 | ||
168 | Alpine:: test /etc/alpine-release | |
169 | ||
170 | Gentoo:: test /etc/gentoo-release | |
171 | ||
172 | NOTE: Container start fails if the configured `ostype` differs from the auto | |
173 | detected type. | |
174 | ||
175 | ||
80c0adcb | 176 | [[pct_container_images]] |
d61bab51 DM |
177 | Container Images |
178 | ---------------- | |
179 | ||
8c1189b6 FG |
180 | Container images, sometimes also referred to as ``templates'' or |
181 | ``appliances'', are `tar` archives which contain everything to run a | |
d61bab51 | 182 | container. You can think of it as a tidy container backup. Like most |
8c1189b6 | 183 | modern container toolkits, `pct` uses those images when you create a |
d61bab51 DM |
184 | new container, for example: |
185 | ||
186 | pct create 999 local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
187 | ||
26ca7ff5 | 188 | {pve} itself ships a set of basic templates for most common |
8c1189b6 | 189 | operating systems, and you can download them using the `pveam` (short |
d61bab51 DM |
190 | for {pve} Appliance Manager) command line utility. You can also |
191 | download https://www.turnkeylinux.org/[TurnKey Linux] containers using | |
192 | that tool (or the graphical user interface). | |
193 | ||
3a6fa247 DM |
194 | Our image repositories contain a list of available images, and there |
195 | is a cron job run each day to download that list. You can trigger that | |
196 | update manually with: | |
197 | ||
198 | pveam update | |
199 | ||
200 | After that you can view the list of available images using: | |
201 | ||
202 | pveam available | |
203 | ||
8c1189b6 FG |
204 | You can restrict this large list by specifying the `section` you are |
205 | interested in, for example basic `system` images: | |
3a6fa247 DM |
206 | |
207 | .List available system images | |
208 | ---- | |
209 | # pveam available --section system | |
210 | system archlinux-base_2015-24-29-1_x86_64.tar.gz | |
211 | system centos-7-default_20160205_amd64.tar.xz | |
212 | system debian-6.0-standard_6.0-7_amd64.tar.gz | |
213 | system debian-7.0-standard_7.0-3_amd64.tar.gz | |
214 | system debian-8.0-standard_8.0-1_amd64.tar.gz | |
215 | system ubuntu-12.04-standard_12.04-1_amd64.tar.gz | |
216 | system ubuntu-14.04-standard_14.04-1_amd64.tar.gz | |
217 | system ubuntu-15.04-standard_15.04-1_amd64.tar.gz | |
218 | system ubuntu-15.10-standard_15.10-1_amd64.tar.gz | |
219 | ---- | |
220 | ||
a8e99754 | 221 | Before you can use such a template, you need to download them into one |
8c1189b6 | 222 | of your storages. You can simply use storage `local` for that |
3a6fa247 DM |
223 | purpose. For clustered installations, it is preferred to use a shared |
224 | storage so that all nodes can access those images. | |
225 | ||
226 | pveam download local debian-8.0-standard_8.0-1_amd64.tar.gz | |
227 | ||
24f73a63 | 228 | You are now ready to create containers using that image, and you can |
8c1189b6 | 229 | list all downloaded images on storage `local` with: |
24f73a63 DM |
230 | |
231 | ---- | |
232 | # pveam list local | |
233 | local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz 190.20MB | |
234 | ---- | |
235 | ||
a8e99754 | 236 | The above command shows you the full {pve} volume identifiers. They include |
24f73a63 | 237 | the storage name, and most other {pve} commands can use them. For |
5eba0743 | 238 | example you can delete that image later with: |
24f73a63 DM |
239 | |
240 | pveam remove local:vztmpl/debian-8.0-standard_8.0-1_amd64.tar.gz | |
3a6fa247 | 241 | |
d61bab51 | 242 | |
80c0adcb | 243 | [[pct_container_storage]] |
70a42028 DM |
244 | Container Storage |
245 | ----------------- | |
246 | ||
247 | Traditional containers use a very simple storage model, only allowing | |
248 | a single mount point, the root file system. This was further | |
8c1189b6 FG |
249 | restricted to specific file system types like `ext4` and `nfs`. |
250 | Additional mounts are often done by user provided scripts. This turned | |
a8e99754 | 251 | out to be complex and error prone, so we try to avoid that now. |
70a42028 DM |
252 | |
253 | Our new LXC based container model is more flexible regarding | |
254 | storage. First, you can have more than a single mount point. This | |
255 | allows you to choose a suitable storage for each application. For | |
256 | example, you can use a relatively slow (and thus cheap) storage for | |
257 | the container root file system. Then you can use a second mount point | |
258 | to mount a very fast, distributed storage for your database | |
259 | application. | |
260 | ||
261 | The second big improvement is that you can use any storage type | |
262 | supported by the {pve} storage library. That means that you can store | |
8c1189b6 FG |
263 | your containers on local `lvmthin` or `zfs`, shared `iSCSI` storage, |
264 | or even on distributed storage systems like `ceph`. It also enables us | |
265 | to use advanced storage features like snapshots and clones. `vzdump` | |
a8e99754 | 266 | can also use the snapshot feature to provide consistent container |
70a42028 DM |
267 | backups. |
268 | ||
269 | Last but not least, you can also mount local devices directly, or | |
270 | mount local directories using bind mounts. That way you can access | |
271 | local storage inside containers with zero overhead. Such bind mounts | |
a8e99754 | 272 | also provide an easy way to share data between different containers. |
70a42028 | 273 | |
eeecce95 | 274 | |
9e44e493 DM |
275 | Mount Points |
276 | ~~~~~~~~~~~~ | |
eeecce95 | 277 | |
01639994 FG |
278 | The root mount point is configured with the `rootfs` property, and you can |
279 | configure up to 10 additional mount points. The corresponding options | |
280 | are called `mp0` to `mp9`, and they can contain the following setting: | |
281 | ||
282 | include::pct-mountpoint-opts.adoc[] | |
283 | ||
9e44e493 DM |
284 | Currently there are basically three types of mount points: storage backed |
285 | mount points, bind mounts and device mounts. | |
286 | ||
5eba0743 | 287 | .Typical container `rootfs` configuration |
4c3b5c77 DM |
288 | ---- |
289 | rootfs: thin1:base-100-disk-1,size=8G | |
290 | ---- | |
291 | ||
292 | ||
5eba0743 | 293 | Storage Backed Mount Points |
4c3b5c77 | 294 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
01639994 | 295 | |
9e44e493 | 296 | Storage backed mount points are managed by the {pve} storage subsystem and come |
eeecce95 WB |
297 | in three different flavors: |
298 | ||
5eba0743 | 299 | - Image based: these are raw images containing a single ext4 formatted file |
eeecce95 | 300 | system. |
5eba0743 | 301 | - ZFS subvolumes: these are technically bind mounts, but with managed storage, |
eeecce95 WB |
302 | and thus allow resizing and snapshotting. |
303 | - Directories: passing `size=0` triggers a special case where instead of a raw | |
304 | image a directory is created. | |
305 | ||
4c3b5c77 | 306 | |
5eba0743 | 307 | Bind Mount Points |
4c3b5c77 | 308 | ^^^^^^^^^^^^^^^^^ |
01639994 | 309 | |
9baca183 FG |
310 | Bind mounts allow you to access arbitrary directories from your Proxmox VE host |
311 | inside a container. Some potential use cases are: | |
312 | ||
313 | - Accessing your home directory in the guest | |
314 | - Accessing an USB device directory in the guest | |
acccc49b | 315 | - Accessing an NFS mount from the host in the guest |
9baca183 | 316 | |
eeecce95 | 317 | Bind mounts are considered to not be managed by the storage subsystem, so you |
9baca183 | 318 | cannot make snapshots or deal with quotas from inside the container. With |
eeecce95 | 319 | unprivileged containers you might run into permission problems caused by the |
9baca183 FG |
320 | user mapping and cannot use ACLs. |
321 | ||
8c1189b6 | 322 | NOTE: The contents of bind mount points are not backed up when using `vzdump`. |
eeecce95 | 323 | |
6b707f2c FG |
324 | WARNING: For security reasons, bind mounts should only be established |
325 | using source directories especially reserved for this purpose, e.g., a | |
326 | directory hierarchy under `/mnt/bindmounts`. Never bind mount system | |
327 | directories like `/`, `/var` or `/etc` into a container - this poses a | |
9baca183 FG |
328 | great security risk. |
329 | ||
330 | NOTE: The bind mount source path must not contain any symlinks. | |
331 | ||
332 | For example, to make the directory `/mnt/bindmounts/shared` accessible in the | |
333 | container with ID `100` under the path `/shared`, use a configuration line like | |
8c1189b6 FG |
334 | `mp0: /mnt/bindmounts/shared,mp=/shared` in `/etc/pve/lxc/100.conf`. |
335 | Alternatively, use `pct set 100 -mp0 /mnt/bindmounts/shared,mp=/shared` to | |
9baca183 | 336 | achieve the same result. |
6b707f2c | 337 | |
4c3b5c77 | 338 | |
5eba0743 | 339 | Device Mount Points |
4c3b5c77 | 340 | ^^^^^^^^^^^^^^^^^^^ |
fe154a4f | 341 | |
7432d78e FG |
342 | Device mount points allow to mount block devices of the host directly into the |
343 | container. Similar to bind mounts, device mounts are not managed by {PVE}'s | |
344 | storage subsystem, but the `quota` and `acl` options will be honored. | |
345 | ||
346 | NOTE: Device mount points should only be used under special circumstances. In | |
347 | most cases a storage backed mount point offers the same performance and a lot | |
348 | more features. | |
349 | ||
8c1189b6 | 350 | NOTE: The contents of device mount points are not backed up when using `vzdump`. |
01639994 | 351 | |
4c3b5c77 | 352 | |
5eba0743 | 353 | FUSE Mounts |
4c3b5c77 | 354 | ~~~~~~~~~~~ |
01639994 FG |
355 | |
356 | WARNING: Because of existing issues in the Linux kernel's freezer | |
357 | subsystem the usage of FUSE mounts inside a container is strongly | |
358 | advised against, as containers need to be frozen for suspend or | |
359 | snapshot mode backups. | |
fe154a4f | 360 | |
01639994 FG |
361 | If FUSE mounts cannot be replaced by other mounting mechanisms or storage |
362 | technologies, it is possible to establish the FUSE mount on the Proxmox host | |
363 | and use a bind mount point to make it accessible inside the container. | |
364 | ||
01639994 | 365 | |
5eba0743 | 366 | Using Quotas Inside Containers |
04c569f6 | 367 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
d6ed3622 | 368 | |
9e44e493 DM |
369 | Quotas allow to set limits inside a container for the amount of disk |
370 | space that each user can use. This only works on ext4 image based | |
371 | storage types and currently does not work with unprivileged | |
372 | containers. | |
d6ed3622 | 373 | |
9e44e493 DM |
374 | Activating the `quota` option causes the following mount options to be |
375 | used for a mount point: | |
376 | `usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0` | |
d6ed3622 | 377 | |
9e44e493 DM |
378 | This allows quotas to be used like you would on any other system. You |
379 | can initialize the `/aquota.user` and `/aquota.group` files by running | |
d6ed3622 | 380 | |
9e44e493 DM |
381 | ---- |
382 | quotacheck -cmug / | |
383 | quotaon / | |
384 | ---- | |
d6ed3622 | 385 | |
166e63d6 FG |
386 | and edit the quotas via the `edquota` command. Refer to the documentation |
387 | of the distribution running inside the container for details. | |
388 | ||
9e44e493 DM |
389 | NOTE: You need to run the above commands for every mount point by passing |
390 | the mount point's path instead of just `/`. | |
391 | ||
d6ed3622 | 392 | |
5eba0743 | 393 | Using ACLs Inside Containers |
04c569f6 | 394 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
6c60aebf | 395 | |
5eba0743 | 396 | The standard Posix **A**ccess **C**ontrol **L**ists are also available inside containers. |
6c60aebf EK |
397 | ACLs allow you to set more detailed file ownership than the traditional user/ |
398 | group/others model. | |
d6ed3622 | 399 | |
04c569f6 | 400 | |
80c0adcb | 401 | [[pct_container_network]] |
04c569f6 DM |
402 | Container Network |
403 | ----------------- | |
404 | ||
bac8c385 | 405 | You can configure up to 10 network interfaces for a single |
8c1189b6 | 406 | container. The corresponding options are called `net0` to `net9`, and |
bac8c385 DM |
407 | they can contain the following setting: |
408 | ||
409 | include::pct-network-opts.adoc[] | |
04c569f6 DM |
410 | |
411 | ||
51e33128 FG |
412 | Backup and Restore |
413 | ------------------ | |
414 | ||
5eba0743 | 415 | |
2175e37b FG |
416 | Container Backup |
417 | ~~~~~~~~~~~~~~~~ | |
418 | ||
8c1189b6 FG |
419 | It is possible to use the `vzdump` tool for container backup. Please |
420 | refer to the `vzdump` manual page for details. | |
421 | ||
51e33128 | 422 | |
2175e37b FG |
423 | Restoring Container Backups |
424 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
425 | ||
8c1189b6 FG |
426 | Restoring container backups made with `vzdump` is possible using the |
427 | `pct restore` command. By default, `pct restore` will attempt to restore as much | |
2175e37b FG |
428 | of the backed up container configuration as possible. It is possible to override |
429 | the backed up configuration by manually setting container options on the command | |
8c1189b6 | 430 | line (see the `pct` manual page for details). |
2175e37b | 431 | |
8c1189b6 | 432 | NOTE: `pvesm extractconfig` can be used to view the backed up configuration |
2175e37b FG |
433 | contained in a vzdump archive. |
434 | ||
435 | There are two basic restore modes, only differing by their handling of mount | |
436 | points: | |
437 | ||
4c3b5c77 | 438 | |
8c1189b6 FG |
439 | ``Simple'' Restore Mode |
440 | ^^^^^^^^^^^^^^^^^^^^^^^ | |
2175e37b FG |
441 | |
442 | If neither the `rootfs` parameter nor any of the optional `mpX` parameters | |
443 | are explicitly set, the mount point configuration from the backed up | |
444 | configuration file is restored using the following steps: | |
445 | ||
446 | . Extract mount points and their options from backup | |
447 | . Create volumes for storage backed mount points (on storage provided with the | |
448 | `storage` parameter, or default local storage if unset) | |
449 | . Extract files from backup archive | |
450 | . Add bind and device mount points to restored configuration (limited to root user) | |
451 | ||
452 | NOTE: Since bind and device mount points are never backed up, no files are | |
453 | restored in the last step, but only the configuration options. The assumption | |
454 | is that such mount points are either backed up with another mechanism (e.g., | |
455 | NFS space that is bind mounted into many containers), or not intended to be | |
456 | backed up at all. | |
457 | ||
458 | This simple mode is also used by the container restore operations in the web | |
459 | interface. | |
460 | ||
4c3b5c77 | 461 | |
8c1189b6 FG |
462 | ``Advanced'' Restore Mode |
463 | ^^^^^^^^^^^^^^^^^^^^^^^^^ | |
2175e37b FG |
464 | |
465 | By setting the `rootfs` parameter (and optionally, any combination of `mpX` | |
8c1189b6 | 466 | parameters), the `pct restore` command is automatically switched into an |
2175e37b FG |
467 | advanced mode. This advanced mode completely ignores the `rootfs` and `mpX` |
468 | configuration options contained in the backup archive, and instead only | |
469 | uses the options explicitly provided as parameters. | |
470 | ||
471 | This mode allows flexible configuration of mount point settings at restore time, | |
472 | for example: | |
473 | ||
474 | * Set target storages, volume sizes and other options for each mount point | |
475 | individually | |
476 | * Redistribute backed up files according to new mount point scheme | |
477 | * Restore to device and/or bind mount points (limited to root user) | |
478 | ||
51e33128 | 479 | |
8c1189b6 | 480 | Managing Containers with `pct` |
04c569f6 DM |
481 | ------------------------------ |
482 | ||
8c1189b6 | 483 | `pct` is the tool to manage Linux Containers on {pve}. You can create |
04c569f6 DM |
484 | and destroy containers, and control execution (start, stop, migrate, |
485 | ...). You can use pct to set parameters in the associated config file, | |
486 | like network configuration or memory limits. | |
487 | ||
5eba0743 | 488 | |
04c569f6 DM |
489 | CLI Usage Examples |
490 | ~~~~~~~~~~~~~~~~~~ | |
491 | ||
492 | Create a container based on a Debian template (provided you have | |
5eba0743 | 493 | already downloaded the template via the web interface) |
04c569f6 DM |
494 | |
495 | pct create 100 /var/lib/vz/template/cache/debian-8.0-standard_8.0-1_amd64.tar.gz | |
496 | ||
497 | Start container 100 | |
498 | ||
499 | pct start 100 | |
500 | ||
501 | Start a login session via getty | |
502 | ||
503 | pct console 100 | |
504 | ||
505 | Enter the LXC namespace and run a shell as root user | |
506 | ||
507 | pct enter 100 | |
508 | ||
509 | Display the configuration | |
510 | ||
511 | pct config 100 | |
512 | ||
8c1189b6 | 513 | Add a network interface called `eth0`, bridged to the host bridge `vmbr0`, |
04c569f6 DM |
514 | set the address and gateway, while it's running |
515 | ||
516 | pct set 100 -net0 name=eth0,bridge=vmbr0,ip=192.168.15.147/24,gw=192.168.15.1 | |
517 | ||
518 | Reduce the memory of the container to 512MB | |
519 | ||
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520 | pct set 100 -memory 512 |
521 | ||
04c569f6 | 522 | |
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523 | Obtaining Debugging Logs |
524 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
525 | ||
526 | In case `pct start` is unable to start a specific container, it might be | |
527 | helpful to collect debugging output by running `lxc-start` (replace `ID` with | |
528 | the container's ID): | |
529 | ||
530 | lxc-start -n ID -F -l DEBUG -o /tmp/lxc-ID.log | |
531 | ||
532 | 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. | |
533 | ||
534 | The collected debug log is written to `/tmp/lxc-ID.log`. | |
535 | ||
536 | NOTE: If you have changed the container's configuration since the last start | |
537 | attempt with `pct start`, you need to run `pct start` at least once to also | |
538 | update the configuration used by `lxc-start`. | |
539 | ||
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540 | |
541 | [[pct_configuration]] | |
542 | Configuration | |
543 | ------------- | |
544 | ||
545 | The `/etc/pve/lxc/<CTID>.conf` file stores container configuration, | |
546 | where `<CTID>` is the numeric ID of the given container. Like all | |
547 | other files stored inside `/etc/pve/`, they get automatically | |
548 | replicated to all other cluster nodes. | |
549 | ||
550 | NOTE: CTIDs < 100 are reserved for internal purposes, and CTIDs need to be | |
551 | unique cluster wide. | |
552 | ||
553 | .Example Container Configuration | |
554 | ---- | |
555 | ostype: debian | |
556 | arch: amd64 | |
557 | hostname: www | |
558 | memory: 512 | |
559 | swap: 512 | |
560 | net0: bridge=vmbr0,hwaddr=66:64:66:64:64:36,ip=dhcp,name=eth0,type=veth | |
561 | rootfs: local:107/vm-107-disk-1.raw,size=7G | |
562 | ---- | |
563 | ||
564 | Those configuration files are simple text files, and you can edit them | |
565 | using a normal text editor (`vi`, `nano`, ...). This is sometimes | |
566 | useful to do small corrections, but keep in mind that you need to | |
567 | restart the container to apply such changes. | |
568 | ||
569 | For that reason, it is usually better to use the `pct` command to | |
570 | generate and modify those files, or do the whole thing using the GUI. | |
571 | Our toolkit is smart enough to instantaneously apply most changes to | |
572 | running containers. This feature is called "hot plug", and there is no | |
573 | need to restart the container in that case. | |
574 | ||
575 | ||
576 | File Format | |
577 | ~~~~~~~~~~~ | |
578 | ||
579 | Container configuration files use a simple colon separated key/value | |
580 | format. Each line has the following format: | |
581 | ||
582 | ----- | |
583 | # this is a comment | |
584 | OPTION: value | |
585 | ----- | |
586 | ||
587 | Blank lines in those files are ignored, and lines starting with a `#` | |
588 | character are treated as comments and are also ignored. | |
589 | ||
590 | It is possible to add low-level, LXC style configuration directly, for | |
591 | example: | |
592 | ||
593 | lxc.init_cmd: /sbin/my_own_init | |
594 | ||
595 | or | |
596 | ||
597 | lxc.init_cmd = /sbin/my_own_init | |
598 | ||
599 | Those settings are directly passed to the LXC low-level tools. | |
600 | ||
601 | ||
602 | [[pct_snapshots]] | |
603 | Snapshots | |
604 | ~~~~~~~~~ | |
605 | ||
606 | When you create a snapshot, `pct` stores the configuration at snapshot | |
607 | time into a separate snapshot section within the same configuration | |
608 | file. For example, after creating a snapshot called ``testsnapshot'', | |
609 | your configuration file will look like this: | |
610 | ||
611 | .Container configuration with snapshot | |
612 | ---- | |
613 | memory: 512 | |
614 | swap: 512 | |
615 | parent: testsnaphot | |
616 | ... | |
617 | ||
618 | [testsnaphot] | |
619 | memory: 512 | |
620 | swap: 512 | |
621 | snaptime: 1457170803 | |
622 | ... | |
623 | ---- | |
624 | ||
625 | There are a few snapshot related properties like `parent` and | |
626 | `snaptime`. The `parent` property is used to store the parent/child | |
627 | relationship between snapshots. `snaptime` is the snapshot creation | |
628 | time stamp (Unix epoch). | |
629 | ||
630 | ||
631 | [[pct_options]] | |
632 | Options | |
633 | ~~~~~~~ | |
634 | ||
635 | include::pct.conf.5-opts.adoc[] | |
636 | ||
637 | ||
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638 | Locks |
639 | ----- | |
640 | ||
641 | Container migrations, snapshots and backups (`vzdump`) set a lock to | |
642 | prevent incompatible concurrent actions on the affected container. Sometimes | |
643 | you need to remove such a lock manually (e.g., after a power failure). | |
644 | ||
645 | pct unlock <CTID> | |
646 | ||
647 | CAUTION: Only do that if you are sure the action which set the lock is | |
648 | no longer running. | |
649 | ||
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651 | Technology Overview |
652 | ------------------- | |
653 | ||
80b5819d | 654 | * Integrated into {pve} graphical user interface (GUI) |
0c6b782f | 655 | |
80b5819d | 656 | * LXC (https://linuxcontainers.org/) |
0c6b782f | 657 | |
80b5819d | 658 | * lxcfs to provide containerized /proc file system |
0c6b782f | 659 | |
80b5819d | 660 | * AppArmor |
0c6b782f | 661 | |
80b5819d | 662 | * CRIU: for live migration (planned) |
0c6b782f | 663 | |
80b5819d | 664 | * We use latest available kernels (4.4.X) |
0c6b782f | 665 | |
80b5819d | 666 | * Image based deployment (templates) |
0c6b782f | 667 | |
80b5819d | 668 | * Container setup from host (network, DNS, storage, ...) |
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669 | |
670 | ||
671 | ifdef::manvolnum[] | |
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672 | |
673 | Files | |
674 | ------ | |
675 | ||
676 | `/etc/pve/lxc/<CTID>.conf`:: | |
677 | ||
678 | Configuration file for the container '<CTID>'. | |
679 | ||
680 | ||
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681 | include::pve-copyright.adoc[] |
682 | endif::manvolnum[] | |
683 | ||
684 | ||
685 | ||
686 | ||
687 | ||
688 | ||
689 |