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