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bde0e57d | 1 | [[chapter_pvecm]] |
d8742b0c | 2 | ifdef::manvolnum[] |
b2f242ab DM |
3 | pvecm(1) |
4 | ======== | |
5f09af76 DM |
5 | :pve-toplevel: |
6 | ||
d8742b0c DM |
7 | NAME |
8 | ---- | |
9 | ||
74026b8f | 10 | pvecm - Proxmox VE Cluster Manager |
d8742b0c | 11 | |
49a5e11c | 12 | SYNOPSIS |
d8742b0c DM |
13 | -------- |
14 | ||
15 | include::pvecm.1-synopsis.adoc[] | |
16 | ||
17 | DESCRIPTION | |
18 | ----------- | |
19 | endif::manvolnum[] | |
20 | ||
21 | ifndef::manvolnum[] | |
22 | Cluster Manager | |
23 | =============== | |
5f09af76 | 24 | :pve-toplevel: |
194d2f29 | 25 | endif::manvolnum[] |
5f09af76 | 26 | |
8c1189b6 FG |
27 | The {PVE} cluster manager `pvecm` is a tool to create a group of |
28 | physical servers. Such a group is called a *cluster*. We use the | |
8a865621 | 29 | http://www.corosync.org[Corosync Cluster Engine] for reliable group |
5eba0743 | 30 | communication, and such clusters can consist of up to 32 physical nodes |
8a865621 DM |
31 | (probably more, dependent on network latency). |
32 | ||
8c1189b6 | 33 | `pvecm` can be used to create a new cluster, join nodes to a cluster, |
8a865621 | 34 | leave the cluster, get status information and do various other cluster |
e300cf7d FG |
35 | related tasks. The **P**rox**m**o**x** **C**luster **F**ile **S**ystem (``pmxcfs'') |
36 | is used to transparently distribute the cluster configuration to all cluster | |
8a865621 DM |
37 | nodes. |
38 | ||
39 | Grouping nodes into a cluster has the following advantages: | |
40 | ||
41 | * Centralized, web based management | |
42 | ||
5eba0743 | 43 | * Multi-master clusters: each node can do all management task |
8a865621 | 44 | |
8c1189b6 FG |
45 | * `pmxcfs`: database-driven file system for storing configuration files, |
46 | replicated in real-time on all nodes using `corosync`. | |
8a865621 | 47 | |
5eba0743 | 48 | * Easy migration of virtual machines and containers between physical |
8a865621 DM |
49 | hosts |
50 | ||
51 | * Fast deployment | |
52 | ||
53 | * Cluster-wide services like firewall and HA | |
54 | ||
55 | ||
56 | Requirements | |
57 | ------------ | |
58 | ||
8c1189b6 | 59 | * All nodes must be in the same network as `corosync` uses IP Multicast |
8a865621 | 60 | to communicate between nodes (also see |
ceabe189 | 61 | http://www.corosync.org[Corosync Cluster Engine]). Corosync uses UDP |
ff72a2ba | 62 | ports 5404 and 5405 for cluster communication. |
ceabe189 DM |
63 | + |
64 | NOTE: Some switches do not support IP multicast by default and must be | |
65 | manually enabled first. | |
8a865621 DM |
66 | |
67 | * Date and time have to be synchronized. | |
68 | ||
ceabe189 | 69 | * SSH tunnel on TCP port 22 between nodes is used. |
8a865621 | 70 | |
ceabe189 DM |
71 | * If you are interested in High Availability, you need to have at |
72 | least three nodes for reliable quorum. All nodes should have the | |
73 | same version. | |
8a865621 DM |
74 | |
75 | * We recommend a dedicated NIC for the cluster traffic, especially if | |
76 | you use shared storage. | |
77 | ||
d4a9910f DL |
78 | * Root password of a cluster node is required for adding nodes. |
79 | ||
8a865621 | 80 | NOTE: It is not possible to mix Proxmox VE 3.x and earlier with |
ceabe189 | 81 | Proxmox VE 4.0 cluster nodes. |
8a865621 DM |
82 | |
83 | ||
ceabe189 DM |
84 | Preparing Nodes |
85 | --------------- | |
8a865621 DM |
86 | |
87 | First, install {PVE} on all nodes. Make sure that each node is | |
88 | installed with the final hostname and IP configuration. Changing the | |
89 | hostname and IP is not possible after cluster creation. | |
90 | ||
d4a9910f | 91 | Currently the cluster creation can either be done on the console(login via `ssh`) or the GUI. |
8a865621 | 92 | |
11202f1d | 93 | [[pvecm_create_cluster]] |
8a865621 | 94 | Create the Cluster |
ceabe189 | 95 | ------------------ |
8a865621 | 96 | |
8c1189b6 | 97 | Login via `ssh` to the first {pve} node. Use a unique name for your cluster. |
d4a9910f | 98 | This name cannot be changed later. The cluster name follows the same rules as node names. |
8a865621 DM |
99 | |
100 | hp1# pvecm create YOUR-CLUSTER-NAME | |
101 | ||
63f956c8 DM |
102 | CAUTION: The cluster name is used to compute the default multicast |
103 | address. Please use unique cluster names if you run more than one | |
104 | cluster inside your network. | |
105 | ||
8a865621 DM |
106 | To check the state of your cluster use: |
107 | ||
108 | hp1# pvecm status | |
109 | ||
82445c4e TL |
110 | Multiple Clusters In Same Network |
111 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
112 | ||
113 | It is possible to create multiple clusters in the same physical or logical | |
114 | network. Each cluster must have a unique name, which is used to generate the | |
115 | cluster's multicast group address. As long as no duplicate cluster names are | |
116 | configured in one network segment, the different clusters won't interfere with | |
117 | each other. | |
118 | ||
119 | If multiple clusters operate in a single network it may be beneficial to setup | |
120 | an IGMP querier and enable IGMP Snooping in said network. This may reduce the | |
121 | load of the network significantly because multicast packets are only delivered | |
122 | to endpoints of the respective member nodes. | |
123 | ||
8a865621 | 124 | |
11202f1d | 125 | [[pvecm_join_node_to_cluster]] |
8a865621 | 126 | Adding Nodes to the Cluster |
ceabe189 | 127 | --------------------------- |
8a865621 | 128 | |
8c1189b6 | 129 | Login via `ssh` to the node you want to add. |
8a865621 DM |
130 | |
131 | hp2# pvecm add IP-ADDRESS-CLUSTER | |
132 | ||
133 | For `IP-ADDRESS-CLUSTER` use the IP from an existing cluster node. | |
134 | ||
5eba0743 | 135 | CAUTION: A new node cannot hold any VMs, because you would get |
7980581f | 136 | conflicts about identical VM IDs. Also, all existing configuration in |
8c1189b6 FG |
137 | `/etc/pve` is overwritten when you join a new node to the cluster. To |
138 | workaround, use `vzdump` to backup and restore to a different VMID after | |
7980581f | 139 | adding the node to the cluster. |
8a865621 DM |
140 | |
141 | To check the state of cluster: | |
142 | ||
143 | # pvecm status | |
144 | ||
ceabe189 | 145 | .Cluster status after adding 4 nodes |
8a865621 DM |
146 | ---- |
147 | hp2# pvecm status | |
148 | Quorum information | |
149 | ~~~~~~~~~~~~~~~~~~ | |
150 | Date: Mon Apr 20 12:30:13 2015 | |
151 | Quorum provider: corosync_votequorum | |
152 | Nodes: 4 | |
153 | Node ID: 0x00000001 | |
154 | Ring ID: 1928 | |
155 | Quorate: Yes | |
156 | ||
157 | Votequorum information | |
158 | ~~~~~~~~~~~~~~~~~~~~~~ | |
159 | Expected votes: 4 | |
160 | Highest expected: 4 | |
161 | Total votes: 4 | |
162 | Quorum: 2 | |
163 | Flags: Quorate | |
164 | ||
165 | Membership information | |
166 | ~~~~~~~~~~~~~~~~~~~~~~ | |
167 | Nodeid Votes Name | |
168 | 0x00000001 1 192.168.15.91 | |
169 | 0x00000002 1 192.168.15.92 (local) | |
170 | 0x00000003 1 192.168.15.93 | |
171 | 0x00000004 1 192.168.15.94 | |
172 | ---- | |
173 | ||
174 | If you only want the list of all nodes use: | |
175 | ||
176 | # pvecm nodes | |
177 | ||
5eba0743 | 178 | .List nodes in a cluster |
8a865621 DM |
179 | ---- |
180 | hp2# pvecm nodes | |
181 | ||
182 | Membership information | |
183 | ~~~~~~~~~~~~~~~~~~~~~~ | |
184 | Nodeid Votes Name | |
185 | 1 1 hp1 | |
186 | 2 1 hp2 (local) | |
187 | 3 1 hp3 | |
188 | 4 1 hp4 | |
189 | ---- | |
190 | ||
82d52451 | 191 | [[adding-nodes-with-separated-cluster-network]] |
e4ec4154 TL |
192 | Adding Nodes With Separated Cluster Network |
193 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
194 | ||
195 | When adding a node to a cluster with a separated cluster network you need to | |
196 | use the 'ringX_addr' parameters to set the nodes address on those networks: | |
197 | ||
198 | [source,bash] | |
4d19cb00 | 199 | ---- |
e4ec4154 | 200 | pvecm add IP-ADDRESS-CLUSTER -ring0_addr IP-ADDRESS-RING0 |
4d19cb00 | 201 | ---- |
e4ec4154 TL |
202 | |
203 | If you want to use the Redundant Ring Protocol you will also want to pass the | |
204 | 'ring1_addr' parameter. | |
205 | ||
8a865621 DM |
206 | |
207 | Remove a Cluster Node | |
ceabe189 | 208 | --------------------- |
8a865621 DM |
209 | |
210 | CAUTION: Read carefully the procedure before proceeding, as it could | |
211 | not be what you want or need. | |
212 | ||
213 | Move all virtual machines from the node. Make sure you have no local | |
214 | data or backups you want to keep, or save them accordingly. | |
e8503c6c | 215 | In the following example we will remove the node hp4 from the cluster. |
8a865621 | 216 | |
e8503c6c EK |
217 | Log in to a *different* cluster node (not hp4), and issue a `pvecm nodes` |
218 | command to identify the node ID to remove: | |
8a865621 DM |
219 | |
220 | ---- | |
221 | hp1# pvecm nodes | |
222 | ||
223 | Membership information | |
224 | ~~~~~~~~~~~~~~~~~~~~~~ | |
225 | Nodeid Votes Name | |
226 | 1 1 hp1 (local) | |
227 | 2 1 hp2 | |
228 | 3 1 hp3 | |
229 | 4 1 hp4 | |
230 | ---- | |
231 | ||
e8503c6c EK |
232 | |
233 | At this point you must power off hp4 and | |
234 | make sure that it will not power on again (in the network) as it | |
235 | is. | |
236 | ||
237 | IMPORTANT: As said above, it is critical to power off the node | |
238 | *before* removal, and make sure that it will *never* power on again | |
239 | (in the existing cluster network) as it is. | |
240 | If you power on the node as it is, your cluster will be screwed up and | |
241 | it could be difficult to restore a clean cluster state. | |
242 | ||
243 | After powering off the node hp4, we can safely remove it from the cluster. | |
8a865621 DM |
244 | |
245 | hp1# pvecm delnode hp4 | |
246 | ||
247 | If the operation succeeds no output is returned, just check the node | |
8c1189b6 | 248 | list again with `pvecm nodes` or `pvecm status`. You should see |
8a865621 DM |
249 | something like: |
250 | ||
251 | ---- | |
252 | hp1# pvecm status | |
253 | ||
254 | Quorum information | |
255 | ~~~~~~~~~~~~~~~~~~ | |
256 | Date: Mon Apr 20 12:44:28 2015 | |
257 | Quorum provider: corosync_votequorum | |
258 | Nodes: 3 | |
259 | Node ID: 0x00000001 | |
260 | Ring ID: 1992 | |
261 | Quorate: Yes | |
262 | ||
263 | Votequorum information | |
264 | ~~~~~~~~~~~~~~~~~~~~~~ | |
265 | Expected votes: 3 | |
266 | Highest expected: 3 | |
267 | Total votes: 3 | |
268 | Quorum: 3 | |
269 | Flags: Quorate | |
270 | ||
271 | Membership information | |
272 | ~~~~~~~~~~~~~~~~~~~~~~ | |
273 | Nodeid Votes Name | |
274 | 0x00000001 1 192.168.15.90 (local) | |
275 | 0x00000002 1 192.168.15.91 | |
276 | 0x00000003 1 192.168.15.92 | |
277 | ---- | |
278 | ||
8a865621 DM |
279 | If, for whatever reason, you want that this server joins the same |
280 | cluster again, you have to | |
281 | ||
26ca7ff5 | 282 | * reinstall {pve} on it from scratch |
8a865621 DM |
283 | |
284 | * then join it, as explained in the previous section. | |
d8742b0c | 285 | |
38ae8db3 | 286 | [[pvecm_separate_node_without_reinstall]] |
555e966b TL |
287 | Separate A Node Without Reinstalling |
288 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
289 | ||
290 | CAUTION: This is *not* the recommended method, proceed with caution. Use the | |
291 | above mentioned method if you're unsure. | |
292 | ||
293 | You can also separate a node from a cluster without reinstalling it from | |
294 | scratch. But after removing the node from the cluster it will still have | |
295 | access to the shared storages! This must be resolved before you start removing | |
296 | the node from the cluster. A {pve} cluster cannot share the exact same | |
2ea5c4a5 TL |
297 | storage with another cluster, as storage locking doesn't work over cluster |
298 | boundary. Further, it may also lead to VMID conflicts. | |
555e966b | 299 | |
3be22308 TL |
300 | Its suggested that you create a new storage where only the node which you want |
301 | to separate has access. This can be an new export on your NFS or a new Ceph | |
302 | pool, to name a few examples. Its just important that the exact same storage | |
303 | does not gets accessed by multiple clusters. After setting this storage up move | |
304 | all data from the node and its VMs to it. Then you are ready to separate the | |
305 | node from the cluster. | |
555e966b TL |
306 | |
307 | WARNING: Ensure all shared resources are cleanly separated! You will run into | |
308 | conflicts and problems else. | |
309 | ||
310 | First stop the corosync and the pve-cluster services on the node: | |
311 | [source,bash] | |
4d19cb00 | 312 | ---- |
555e966b TL |
313 | systemctl stop pve-cluster |
314 | systemctl stop corosync | |
4d19cb00 | 315 | ---- |
555e966b TL |
316 | |
317 | Start the cluster filesystem again in local mode: | |
318 | [source,bash] | |
4d19cb00 | 319 | ---- |
555e966b | 320 | pmxcfs -l |
4d19cb00 | 321 | ---- |
555e966b TL |
322 | |
323 | Delete the corosync configuration files: | |
324 | [source,bash] | |
4d19cb00 | 325 | ---- |
555e966b TL |
326 | rm /etc/pve/corosync.conf |
327 | rm /etc/corosync/* | |
4d19cb00 | 328 | ---- |
555e966b TL |
329 | |
330 | You can now start the filesystem again as normal service: | |
331 | [source,bash] | |
4d19cb00 | 332 | ---- |
555e966b TL |
333 | killall pmxcfs |
334 | systemctl start pve-cluster | |
4d19cb00 | 335 | ---- |
555e966b TL |
336 | |
337 | The node is now separated from the cluster. You can deleted it from a remaining | |
338 | node of the cluster with: | |
339 | [source,bash] | |
4d19cb00 | 340 | ---- |
555e966b | 341 | pvecm delnode oldnode |
4d19cb00 | 342 | ---- |
555e966b TL |
343 | |
344 | If the command failed, because the remaining node in the cluster lost quorum | |
345 | when the now separate node exited, you may set the expected votes to 1 as a workaround: | |
346 | [source,bash] | |
4d19cb00 | 347 | ---- |
555e966b | 348 | pvecm expected 1 |
4d19cb00 | 349 | ---- |
555e966b TL |
350 | |
351 | And the repeat the 'pvecm delnode' command. | |
352 | ||
353 | Now switch back to the separated node, here delete all remaining files left | |
354 | from the old cluster. This ensures that the node can be added to another | |
355 | cluster again without problems. | |
356 | ||
357 | [source,bash] | |
4d19cb00 | 358 | ---- |
555e966b | 359 | rm /var/lib/corosync/* |
4d19cb00 | 360 | ---- |
555e966b TL |
361 | |
362 | As the configuration files from the other nodes are still in the cluster | |
363 | filesystem you may want to clean those up too. Remove simply the whole | |
364 | directory recursive from '/etc/pve/nodes/NODENAME', but check three times that | |
365 | you used the correct one before deleting it. | |
366 | ||
367 | CAUTION: The nodes SSH keys are still in the 'authorized_key' file, this means | |
368 | the nodes can still connect to each other with public key authentication. This | |
369 | should be fixed by removing the respective keys from the | |
370 | '/etc/pve/priv/authorized_keys' file. | |
d8742b0c | 371 | |
806ef12d DM |
372 | Quorum |
373 | ------ | |
374 | ||
375 | {pve} use a quorum-based technique to provide a consistent state among | |
376 | all cluster nodes. | |
377 | ||
378 | [quote, from Wikipedia, Quorum (distributed computing)] | |
379 | ____ | |
380 | A quorum is the minimum number of votes that a distributed transaction | |
381 | has to obtain in order to be allowed to perform an operation in a | |
382 | distributed system. | |
383 | ____ | |
384 | ||
385 | In case of network partitioning, state changes requires that a | |
386 | majority of nodes are online. The cluster switches to read-only mode | |
5eba0743 | 387 | if it loses quorum. |
806ef12d DM |
388 | |
389 | NOTE: {pve} assigns a single vote to each node by default. | |
390 | ||
e4ec4154 TL |
391 | Cluster Network |
392 | --------------- | |
393 | ||
394 | The cluster network is the core of a cluster. All messages sent over it have to | |
395 | be delivered reliable to all nodes in their respective order. In {pve} this | |
396 | part is done by corosync, an implementation of a high performance low overhead | |
397 | high availability development toolkit. It serves our decentralized | |
398 | configuration file system (`pmxcfs`). | |
399 | ||
400 | [[cluster-network-requirements]] | |
401 | Network Requirements | |
402 | ~~~~~~~~~~~~~~~~~~~~ | |
403 | This needs a reliable network with latencies under 2 milliseconds (LAN | |
404 | performance) to work properly. While corosync can also use unicast for | |
405 | communication between nodes its **highly recommended** to have a multicast | |
406 | capable network. The network should not be used heavily by other members, | |
407 | ideally corosync runs on its own network. | |
408 | *never* share it with network where storage communicates too. | |
409 | ||
410 | Before setting up a cluster it is good practice to check if the network is fit | |
411 | for that purpose. | |
412 | ||
413 | * Ensure that all nodes are in the same subnet. This must only be true for the | |
414 | network interfaces used for cluster communication (corosync). | |
415 | ||
416 | * Ensure all nodes can reach each other over those interfaces, using `ping` is | |
417 | enough for a basic test. | |
418 | ||
419 | * Ensure that multicast works in general and a high package rates. This can be | |
420 | done with the `omping` tool. The final "%loss" number should be < 1%. | |
9e73d831 | 421 | + |
e4ec4154 TL |
422 | [source,bash] |
423 | ---- | |
424 | omping -c 10000 -i 0.001 -F -q NODE1-IP NODE2-IP ... | |
425 | ---- | |
426 | ||
427 | * Ensure that multicast communication works over an extended period of time. | |
a181f090 | 428 | This uncovers problems where IGMP snooping is activated on the network but |
e4ec4154 TL |
429 | no multicast querier is active. This test has a duration of around 10 |
430 | minutes. | |
9e73d831 | 431 | + |
e4ec4154 | 432 | [source,bash] |
4d19cb00 | 433 | ---- |
e4ec4154 | 434 | omping -c 600 -i 1 -q NODE1-IP NODE2-IP ... |
4d19cb00 | 435 | ---- |
e4ec4154 TL |
436 | |
437 | Your network is not ready for clustering if any of these test fails. Recheck | |
438 | your network configuration. Especially switches are notorious for having | |
439 | multicast disabled by default or IGMP snooping enabled with no IGMP querier | |
440 | active. | |
441 | ||
442 | In smaller cluster its also an option to use unicast if you really cannot get | |
443 | multicast to work. | |
444 | ||
445 | Separate Cluster Network | |
446 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
447 | ||
448 | When creating a cluster without any parameters the cluster network is generally | |
449 | shared with the Web UI and the VMs and its traffic. Depending on your setup | |
450 | even storage traffic may get sent over the same network. Its recommended to | |
451 | change that, as corosync is a time critical real time application. | |
452 | ||
453 | Setting Up A New Network | |
454 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
455 | ||
456 | First you have to setup a new network interface. It should be on a physical | |
457 | separate network. Ensure that your network fulfills the | |
458 | <<cluster-network-requirements,cluster network requirements>>. | |
459 | ||
460 | Separate On Cluster Creation | |
461 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
462 | ||
463 | This is possible through the 'ring0_addr' and 'bindnet0_addr' parameter of | |
464 | the 'pvecm create' command used for creating a new cluster. | |
465 | ||
44f38275 | 466 | If you have setup an additional NIC with a static address on 10.10.10.1/25 |
e4ec4154 TL |
467 | and want to send and receive all cluster communication over this interface |
468 | you would execute: | |
469 | ||
470 | [source,bash] | |
4d19cb00 | 471 | ---- |
e4ec4154 | 472 | pvecm create test --ring0_addr 10.10.10.1 --bindnet0_addr 10.10.10.0 |
4d19cb00 | 473 | ---- |
e4ec4154 TL |
474 | |
475 | To check if everything is working properly execute: | |
476 | [source,bash] | |
4d19cb00 | 477 | ---- |
e4ec4154 | 478 | systemctl status corosync |
4d19cb00 | 479 | ---- |
e4ec4154 | 480 | |
266cb17b WB |
481 | Afterwards, proceed as descripted in the section to |
482 | <<adding-nodes-with-separated-cluster-network,add nodes with a separated cluster network>>. | |
82d52451 | 483 | |
e4ec4154 TL |
484 | [[separate-cluster-net-after-creation]] |
485 | Separate After Cluster Creation | |
486 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
487 | ||
488 | You can do this also if you have already created a cluster and want to switch | |
489 | its communication to another network, without rebuilding the whole cluster. | |
490 | This change may lead to short durations of quorum loss in the cluster, as nodes | |
491 | have to restart corosync and come up one after the other on the new network. | |
492 | ||
493 | Check how to <<edit-corosync-conf,edit the corosync.conf file>> first. | |
494 | The open it and you should see a file similar to: | |
495 | ||
496 | ---- | |
497 | logging { | |
498 | debug: off | |
499 | to_syslog: yes | |
500 | } | |
501 | ||
502 | nodelist { | |
503 | ||
504 | node { | |
505 | name: due | |
506 | nodeid: 2 | |
507 | quorum_votes: 1 | |
508 | ring0_addr: due | |
509 | } | |
510 | ||
511 | node { | |
512 | name: tre | |
513 | nodeid: 3 | |
514 | quorum_votes: 1 | |
515 | ring0_addr: tre | |
516 | } | |
517 | ||
518 | node { | |
519 | name: uno | |
520 | nodeid: 1 | |
521 | quorum_votes: 1 | |
522 | ring0_addr: uno | |
523 | } | |
524 | ||
525 | } | |
526 | ||
527 | quorum { | |
528 | provider: corosync_votequorum | |
529 | } | |
530 | ||
531 | totem { | |
532 | cluster_name: thomas-testcluster | |
533 | config_version: 3 | |
534 | ip_version: ipv4 | |
535 | secauth: on | |
536 | version: 2 | |
537 | interface { | |
538 | bindnetaddr: 192.168.30.50 | |
539 | ringnumber: 0 | |
540 | } | |
541 | ||
542 | } | |
543 | ---- | |
544 | ||
545 | The first you want to do is add the 'name' properties in the node entries if | |
546 | you do not see them already. Those *must* match the node name. | |
547 | ||
548 | Then replace the address from the 'ring0_addr' properties with the new | |
549 | addresses. You may use plain IP addresses or also hostnames here. If you use | |
550 | hostnames ensure that they are resolvable from all nodes. | |
551 | ||
552 | In my example I want to switch my cluster communication to the 10.10.10.1/25 | |
470d4313 | 553 | network. So I replace all 'ring0_addr' respectively. I also set the bindnetaddr |
e4ec4154 TL |
554 | in the totem section of the config to an address of the new network. It can be |
555 | any address from the subnet configured on the new network interface. | |
556 | ||
557 | After you increased the 'config_version' property the new configuration file | |
558 | should look like: | |
559 | ||
560 | ---- | |
561 | ||
562 | logging { | |
563 | debug: off | |
564 | to_syslog: yes | |
565 | } | |
566 | ||
567 | nodelist { | |
568 | ||
569 | node { | |
570 | name: due | |
571 | nodeid: 2 | |
572 | quorum_votes: 1 | |
573 | ring0_addr: 10.10.10.2 | |
574 | } | |
575 | ||
576 | node { | |
577 | name: tre | |
578 | nodeid: 3 | |
579 | quorum_votes: 1 | |
580 | ring0_addr: 10.10.10.3 | |
581 | } | |
582 | ||
583 | node { | |
584 | name: uno | |
585 | nodeid: 1 | |
586 | quorum_votes: 1 | |
587 | ring0_addr: 10.10.10.1 | |
588 | } | |
589 | ||
590 | } | |
591 | ||
592 | quorum { | |
593 | provider: corosync_votequorum | |
594 | } | |
595 | ||
596 | totem { | |
597 | cluster_name: thomas-testcluster | |
598 | config_version: 4 | |
599 | ip_version: ipv4 | |
600 | secauth: on | |
601 | version: 2 | |
602 | interface { | |
603 | bindnetaddr: 10.10.10.1 | |
604 | ringnumber: 0 | |
605 | } | |
606 | ||
607 | } | |
608 | ---- | |
609 | ||
610 | Now after a final check whether all changed information is correct we save it | |
611 | and see again the <<edit-corosync-conf,edit corosync.conf file>> section to | |
612 | learn how to bring it in effect. | |
613 | ||
614 | As our change cannot be enforced live from corosync we have to do an restart. | |
615 | ||
616 | On a single node execute: | |
617 | [source,bash] | |
4d19cb00 | 618 | ---- |
e4ec4154 | 619 | systemctl restart corosync |
4d19cb00 | 620 | ---- |
e4ec4154 TL |
621 | |
622 | Now check if everything is fine: | |
623 | ||
624 | [source,bash] | |
4d19cb00 | 625 | ---- |
e4ec4154 | 626 | systemctl status corosync |
4d19cb00 | 627 | ---- |
e4ec4154 TL |
628 | |
629 | If corosync runs again correct restart corosync also on all other nodes. | |
630 | They will then join the cluster membership one by one on the new network. | |
631 | ||
11202f1d | 632 | [[pvecm_rrp]] |
e4ec4154 TL |
633 | Redundant Ring Protocol |
634 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
635 | To avoid a single point of failure you should implement counter measurements. | |
636 | This can be on the hardware and operating system level through network bonding. | |
637 | ||
638 | Corosync itself offers also a possibility to add redundancy through the so | |
639 | called 'Redundant Ring Protocol'. This protocol allows running a second totem | |
640 | ring on another network, this network should be physically separated from the | |
641 | other rings network to actually increase availability. | |
642 | ||
643 | RRP On Cluster Creation | |
644 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
645 | ||
646 | The 'pvecm create' command provides the additional parameters 'bindnetX_addr', | |
647 | 'ringX_addr' and 'rrp_mode', can be used for RRP configuration. | |
648 | ||
649 | NOTE: See the <<corosync-conf-glossary,glossary>> if you do not know what each parameter means. | |
650 | ||
651 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
652 | 10.10.20.1/24 subnet you would execute: | |
653 | ||
654 | [source,bash] | |
4d19cb00 | 655 | ---- |
e4ec4154 TL |
656 | pvecm create CLUSTERNAME -bindnet0_addr 10.10.10.1 -ring0_addr 10.10.10.1 \ |
657 | -bindnet1_addr 10.10.20.1 -ring1_addr 10.10.20.1 | |
4d19cb00 | 658 | ---- |
e4ec4154 | 659 | |
6e78f927 | 660 | RRP On Existing Clusters |
e4ec4154 TL |
661 | ~~~~~~~~~~~~~~~~~~~~~~~~ |
662 | ||
6e78f927 TL |
663 | You will take similar steps as described in |
664 | <<separate-cluster-net-after-creation,separating the cluster network>> to | |
665 | enable RRP on an already running cluster. The single difference is, that you | |
666 | will add `ring1` and use it instead of `ring0`. | |
e4ec4154 TL |
667 | |
668 | First add a new `interface` subsection in the `totem` section, set its | |
669 | `ringnumber` property to `1`. Set the interfaces `bindnetaddr` property to an | |
670 | address of the subnet you have configured for your new ring. | |
671 | Further set the `rrp_mode` to `passive`, this is the only stable mode. | |
672 | ||
673 | Then add to each node entry in the `nodelist` section its new `ring1_addr` | |
674 | property with the nodes additional ring address. | |
675 | ||
676 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
677 | 10.10.20.1/24 subnet, the final configuration file should look like: | |
678 | ||
679 | ---- | |
680 | totem { | |
681 | cluster_name: tweak | |
682 | config_version: 9 | |
683 | ip_version: ipv4 | |
684 | rrp_mode: passive | |
685 | secauth: on | |
686 | version: 2 | |
687 | interface { | |
688 | bindnetaddr: 10.10.10.1 | |
689 | ringnumber: 0 | |
690 | } | |
691 | interface { | |
692 | bindnetaddr: 10.10.20.1 | |
693 | ringnumber: 1 | |
694 | } | |
695 | } | |
696 | ||
697 | nodelist { | |
698 | node { | |
699 | name: pvecm1 | |
700 | nodeid: 1 | |
701 | quorum_votes: 1 | |
702 | ring0_addr: 10.10.10.1 | |
703 | ring1_addr: 10.10.20.1 | |
704 | } | |
705 | ||
706 | node { | |
707 | name: pvecm2 | |
708 | nodeid: 2 | |
709 | quorum_votes: 1 | |
710 | ring0_addr: 10.10.10.2 | |
711 | ring1_addr: 10.10.20.2 | |
712 | } | |
713 | ||
714 | [...] # other cluster nodes here | |
715 | } | |
716 | ||
717 | [...] # other remaining config sections here | |
718 | ||
719 | ---- | |
720 | ||
7d48940b DM |
721 | Bring it in effect like described in the |
722 | <<edit-corosync-conf,edit the corosync.conf file>> section. | |
e4ec4154 TL |
723 | |
724 | This is a change which cannot take live in effect and needs at least a restart | |
725 | of corosync. Recommended is a restart of the whole cluster. | |
726 | ||
727 | If you cannot reboot the whole cluster ensure no High Availability services are | |
728 | configured and the stop the corosync service on all nodes. After corosync is | |
729 | stopped on all nodes start it one after the other again. | |
730 | ||
731 | Corosync Configuration | |
732 | ---------------------- | |
733 | ||
470d4313 | 734 | The `/etc/pve/corosync.conf` file plays a central role in {pve} cluster. It |
e4ec4154 TL |
735 | controls the cluster member ship and its network. |
736 | For reading more about it check the corosync.conf man page: | |
737 | [source,bash] | |
4d19cb00 | 738 | ---- |
e4ec4154 | 739 | man corosync.conf |
4d19cb00 | 740 | ---- |
e4ec4154 TL |
741 | |
742 | For node membership you should always use the `pvecm` tool provided by {pve}. | |
743 | You may have to edit the configuration file manually for other changes. | |
744 | Here are a few best practice tips for doing this. | |
745 | ||
746 | [[edit-corosync-conf]] | |
747 | Edit corosync.conf | |
748 | ~~~~~~~~~~~~~~~~~~ | |
749 | ||
750 | Editing the corosync.conf file can be not always straight forward. There are | |
751 | two on each cluster, one in `/etc/pve/corosync.conf` and the other in | |
752 | `/etc/corosync/corosync.conf`. Editing the one in our cluster file system will | |
753 | propagate the changes to the local one, but not vice versa. | |
754 | ||
755 | The configuration will get updated automatically as soon as the file changes. | |
756 | This means changes which can be integrated in a running corosync will take | |
757 | instantly effect. So you should always make a copy and edit that instead, to | |
758 | avoid triggering some unwanted changes by an in between safe. | |
759 | ||
760 | [source,bash] | |
4d19cb00 | 761 | ---- |
e4ec4154 | 762 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.new |
4d19cb00 | 763 | ---- |
e4ec4154 TL |
764 | |
765 | Then open the Config file with your favorite editor, `nano` and `vim.tiny` are | |
766 | preinstalled on {pve} for example. | |
767 | ||
768 | NOTE: Always increment the 'config_version' number on configuration changes, | |
769 | omitting this can lead to problems. | |
770 | ||
771 | After making the necessary changes create another copy of the current working | |
772 | configuration file. This serves as a backup if the new configuration fails to | |
773 | apply or makes problems in other ways. | |
774 | ||
775 | [source,bash] | |
4d19cb00 | 776 | ---- |
e4ec4154 | 777 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.bak |
4d19cb00 | 778 | ---- |
e4ec4154 TL |
779 | |
780 | Then move the new configuration file over the old one: | |
781 | [source,bash] | |
4d19cb00 | 782 | ---- |
e4ec4154 | 783 | mv /etc/pve/corosync.conf.new /etc/pve/corosync.conf |
4d19cb00 | 784 | ---- |
e4ec4154 TL |
785 | |
786 | You may check with the commands | |
787 | [source,bash] | |
4d19cb00 | 788 | ---- |
e4ec4154 TL |
789 | systemctl status corosync |
790 | journalctl -b -u corosync | |
4d19cb00 | 791 | ---- |
e4ec4154 TL |
792 | |
793 | If the change could applied automatically. If not you may have to restart the | |
794 | corosync service via: | |
795 | [source,bash] | |
4d19cb00 | 796 | ---- |
e4ec4154 | 797 | systemctl restart corosync |
4d19cb00 | 798 | ---- |
e4ec4154 TL |
799 | |
800 | On errors check the troubleshooting section below. | |
801 | ||
802 | Troubleshooting | |
803 | ~~~~~~~~~~~~~~~ | |
804 | ||
805 | Issue: 'quorum.expected_votes must be configured' | |
806 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
807 | ||
808 | When corosync starts to fail and you get the following message in the system log: | |
809 | ||
810 | ---- | |
811 | [...] | |
812 | corosync[1647]: [QUORUM] Quorum provider: corosync_votequorum failed to initialize. | |
813 | corosync[1647]: [SERV ] Service engine 'corosync_quorum' failed to load for reason | |
814 | 'configuration error: nodelist or quorum.expected_votes must be configured!' | |
815 | [...] | |
816 | ---- | |
817 | ||
818 | It means that the hostname you set for corosync 'ringX_addr' in the | |
819 | configuration could not be resolved. | |
820 | ||
821 | ||
822 | Write Configuration When Not Quorate | |
823 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
824 | ||
825 | If you need to change '/etc/pve/corosync.conf' on an node with no quorum, and you | |
826 | know what you do, use: | |
827 | [source,bash] | |
4d19cb00 | 828 | ---- |
e4ec4154 | 829 | pvecm expected 1 |
4d19cb00 | 830 | ---- |
e4ec4154 TL |
831 | |
832 | This sets the expected vote count to 1 and makes the cluster quorate. You can | |
833 | now fix your configuration, or revert it back to the last working backup. | |
834 | ||
835 | This is not enough if corosync cannot start anymore. Here its best to edit the | |
836 | local copy of the corosync configuration in '/etc/corosync/corosync.conf' so | |
837 | that corosync can start again. Ensure that on all nodes this configuration has | |
838 | the same content to avoid split brains. If you are not sure what went wrong | |
839 | it's best to ask the Proxmox Community to help you. | |
840 | ||
841 | ||
842 | [[corosync-conf-glossary]] | |
843 | Corosync Configuration Glossary | |
844 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
845 | ||
846 | ringX_addr:: | |
847 | This names the different ring addresses for the corosync totem rings used for | |
848 | the cluster communication. | |
849 | ||
850 | bindnetaddr:: | |
851 | Defines to which interface the ring should bind to. It may be any address of | |
852 | the subnet configured on the interface we want to use. In general its the | |
853 | recommended to just use an address a node uses on this interface. | |
854 | ||
855 | rrp_mode:: | |
856 | Specifies the mode of the redundant ring protocol and may be passive, active or | |
857 | none. Note that use of active is highly experimental and not official | |
858 | supported. Passive is the preferred mode, it may double the cluster | |
859 | communication throughput and increases availability. | |
860 | ||
806ef12d DM |
861 | |
862 | Cluster Cold Start | |
863 | ------------------ | |
864 | ||
865 | It is obvious that a cluster is not quorate when all nodes are | |
866 | offline. This is a common case after a power failure. | |
867 | ||
868 | NOTE: It is always a good idea to use an uninterruptible power supply | |
8c1189b6 | 869 | (``UPS'', also called ``battery backup'') to avoid this state, especially if |
806ef12d DM |
870 | you want HA. |
871 | ||
204231df | 872 | On node startup, the `pve-guests` service is started and waits for |
8c1189b6 | 873 | quorum. Once quorate, it starts all guests which have the `onboot` |
612417fd DM |
874 | flag set. |
875 | ||
876 | When you turn on nodes, or when power comes back after power failure, | |
877 | it is likely that some nodes boots faster than others. Please keep in | |
878 | mind that guest startup is delayed until you reach quorum. | |
806ef12d | 879 | |
054a7e7d | 880 | |
082ea7d9 TL |
881 | Guest Migration |
882 | --------------- | |
883 | ||
054a7e7d DM |
884 | Migrating virtual guests to other nodes is a useful feature in a |
885 | cluster. There are settings to control the behavior of such | |
886 | migrations. This can be done via the configuration file | |
887 | `datacenter.cfg` or for a specific migration via API or command line | |
888 | parameters. | |
889 | ||
da6c7dee DC |
890 | It makes a difference if a Guest is online or offline, or if it has |
891 | local resources (like a local disk). | |
892 | ||
893 | For Details about Virtual Machine Migration see the | |
894 | xref:qm_migration[QEMU/KVM Migration Chapter] | |
895 | ||
896 | For Details about Container Migration see the | |
897 | xref:pct_migration[Container Migration Chapter] | |
082ea7d9 TL |
898 | |
899 | Migration Type | |
900 | ~~~~~~~~~~~~~~ | |
901 | ||
44f38275 | 902 | The migration type defines if the migration data should be sent over an |
d63be10b | 903 | encrypted (`secure`) channel or an unencrypted (`insecure`) one. |
082ea7d9 | 904 | Setting the migration type to insecure means that the RAM content of a |
470d4313 | 905 | virtual guest gets also transferred unencrypted, which can lead to |
b1743473 DM |
906 | information disclosure of critical data from inside the guest (for |
907 | example passwords or encryption keys). | |
054a7e7d DM |
908 | |
909 | Therefore, we strongly recommend using the secure channel if you do | |
910 | not have full control over the network and can not guarantee that no | |
911 | one is eavesdropping to it. | |
082ea7d9 | 912 | |
054a7e7d DM |
913 | NOTE: Storage migration does not follow this setting. Currently, it |
914 | always sends the storage content over a secure channel. | |
915 | ||
916 | Encryption requires a lot of computing power, so this setting is often | |
917 | changed to "unsafe" to achieve better performance. The impact on | |
918 | modern systems is lower because they implement AES encryption in | |
b1743473 DM |
919 | hardware. The performance impact is particularly evident in fast |
920 | networks where you can transfer 10 Gbps or more. | |
082ea7d9 | 921 | |
082ea7d9 TL |
922 | |
923 | Migration Network | |
924 | ~~~~~~~~~~~~~~~~~ | |
925 | ||
a9baa444 TL |
926 | By default, {pve} uses the network in which cluster communication |
927 | takes place to send the migration traffic. This is not optimal because | |
928 | sensitive cluster traffic can be disrupted and this network may not | |
929 | have the best bandwidth available on the node. | |
930 | ||
931 | Setting the migration network parameter allows the use of a dedicated | |
932 | network for the entire migration traffic. In addition to the memory, | |
933 | this also affects the storage traffic for offline migrations. | |
934 | ||
935 | The migration network is set as a network in the CIDR notation. This | |
936 | has the advantage that you do not have to set individual IP addresses | |
937 | for each node. {pve} can determine the real address on the | |
938 | destination node from the network specified in the CIDR form. To | |
939 | enable this, the network must be specified so that each node has one, | |
940 | but only one IP in the respective network. | |
941 | ||
082ea7d9 TL |
942 | |
943 | Example | |
944 | ^^^^^^^ | |
945 | ||
a9baa444 TL |
946 | We assume that we have a three-node setup with three separate |
947 | networks. One for public communication with the Internet, one for | |
948 | cluster communication and a very fast one, which we want to use as a | |
949 | dedicated network for migration. | |
950 | ||
951 | A network configuration for such a setup might look as follows: | |
082ea7d9 TL |
952 | |
953 | ---- | |
7a0d4784 | 954 | iface eno1 inet manual |
082ea7d9 TL |
955 | |
956 | # public network | |
957 | auto vmbr0 | |
958 | iface vmbr0 inet static | |
959 | address 192.X.Y.57 | |
960 | netmask 255.255.250.0 | |
961 | gateway 192.X.Y.1 | |
7a0d4784 | 962 | bridge_ports eno1 |
082ea7d9 TL |
963 | bridge_stp off |
964 | bridge_fd 0 | |
965 | ||
966 | # cluster network | |
7a0d4784 WL |
967 | auto eno2 |
968 | iface eno2 inet static | |
082ea7d9 TL |
969 | address 10.1.1.1 |
970 | netmask 255.255.255.0 | |
971 | ||
972 | # fast network | |
7a0d4784 WL |
973 | auto eno3 |
974 | iface eno3 inet static | |
082ea7d9 TL |
975 | address 10.1.2.1 |
976 | netmask 255.255.255.0 | |
082ea7d9 TL |
977 | ---- |
978 | ||
a9baa444 TL |
979 | Here, we will use the network 10.1.2.0/24 as a migration network. For |
980 | a single migration, you can do this using the `migration_network` | |
981 | parameter of the command line tool: | |
982 | ||
082ea7d9 | 983 | ---- |
b1743473 | 984 | # qm migrate 106 tre --online --migration_network 10.1.2.0/24 |
082ea7d9 TL |
985 | ---- |
986 | ||
a9baa444 TL |
987 | To configure this as the default network for all migrations in the |
988 | cluster, set the `migration` property of the `/etc/pve/datacenter.cfg` | |
989 | file: | |
990 | ||
082ea7d9 | 991 | ---- |
a9baa444 | 992 | # use dedicated migration network |
b1743473 | 993 | migration: secure,network=10.1.2.0/24 |
082ea7d9 TL |
994 | ---- |
995 | ||
a9baa444 TL |
996 | NOTE: The migration type must always be set when the migration network |
997 | gets set in `/etc/pve/datacenter.cfg`. | |
998 | ||
806ef12d | 999 | |
d8742b0c DM |
1000 | ifdef::manvolnum[] |
1001 | include::pve-copyright.adoc[] | |
1002 | endif::manvolnum[] |