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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 | ||
107 | ||
108 | Adding Nodes to the Cluster | |
ceabe189 | 109 | --------------------------- |
8a865621 | 110 | |
8c1189b6 | 111 | Login via `ssh` to the node you want to add. |
8a865621 DM |
112 | |
113 | hp2# pvecm add IP-ADDRESS-CLUSTER | |
114 | ||
115 | For `IP-ADDRESS-CLUSTER` use the IP from an existing cluster node. | |
116 | ||
5eba0743 | 117 | CAUTION: A new node cannot hold any VMs, because you would get |
7980581f | 118 | conflicts about identical VM IDs. Also, all existing configuration in |
8c1189b6 FG |
119 | `/etc/pve` is overwritten when you join a new node to the cluster. To |
120 | workaround, use `vzdump` to backup and restore to a different VMID after | |
7980581f | 121 | adding the node to the cluster. |
8a865621 DM |
122 | |
123 | To check the state of cluster: | |
124 | ||
125 | # pvecm status | |
126 | ||
ceabe189 | 127 | .Cluster status after adding 4 nodes |
8a865621 DM |
128 | ---- |
129 | hp2# pvecm status | |
130 | Quorum information | |
131 | ~~~~~~~~~~~~~~~~~~ | |
132 | Date: Mon Apr 20 12:30:13 2015 | |
133 | Quorum provider: corosync_votequorum | |
134 | Nodes: 4 | |
135 | Node ID: 0x00000001 | |
136 | Ring ID: 1928 | |
137 | Quorate: Yes | |
138 | ||
139 | Votequorum information | |
140 | ~~~~~~~~~~~~~~~~~~~~~~ | |
141 | Expected votes: 4 | |
142 | Highest expected: 4 | |
143 | Total votes: 4 | |
144 | Quorum: 2 | |
145 | Flags: Quorate | |
146 | ||
147 | Membership information | |
148 | ~~~~~~~~~~~~~~~~~~~~~~ | |
149 | Nodeid Votes Name | |
150 | 0x00000001 1 192.168.15.91 | |
151 | 0x00000002 1 192.168.15.92 (local) | |
152 | 0x00000003 1 192.168.15.93 | |
153 | 0x00000004 1 192.168.15.94 | |
154 | ---- | |
155 | ||
156 | If you only want the list of all nodes use: | |
157 | ||
158 | # pvecm nodes | |
159 | ||
5eba0743 | 160 | .List nodes in a cluster |
8a865621 DM |
161 | ---- |
162 | hp2# pvecm nodes | |
163 | ||
164 | Membership information | |
165 | ~~~~~~~~~~~~~~~~~~~~~~ | |
166 | Nodeid Votes Name | |
167 | 1 1 hp1 | |
168 | 2 1 hp2 (local) | |
169 | 3 1 hp3 | |
170 | 4 1 hp4 | |
171 | ---- | |
172 | ||
e4ec4154 TL |
173 | Adding Nodes With Separated Cluster Network |
174 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
175 | ||
176 | When adding a node to a cluster with a separated cluster network you need to | |
177 | use the 'ringX_addr' parameters to set the nodes address on those networks: | |
178 | ||
179 | [source,bash] | |
4d19cb00 | 180 | ---- |
e4ec4154 | 181 | pvecm add IP-ADDRESS-CLUSTER -ring0_addr IP-ADDRESS-RING0 |
4d19cb00 | 182 | ---- |
e4ec4154 TL |
183 | |
184 | If you want to use the Redundant Ring Protocol you will also want to pass the | |
185 | 'ring1_addr' parameter. | |
186 | ||
8a865621 DM |
187 | |
188 | Remove a Cluster Node | |
ceabe189 | 189 | --------------------- |
8a865621 DM |
190 | |
191 | CAUTION: Read carefully the procedure before proceeding, as it could | |
192 | not be what you want or need. | |
193 | ||
194 | Move all virtual machines from the node. Make sure you have no local | |
195 | data or backups you want to keep, or save them accordingly. | |
196 | ||
8c1189b6 | 197 | Log in to one remaining node via ssh. Issue a `pvecm nodes` command to |
7980581f | 198 | identify the node ID: |
8a865621 DM |
199 | |
200 | ---- | |
201 | hp1# pvecm status | |
202 | ||
203 | Quorum information | |
204 | ~~~~~~~~~~~~~~~~~~ | |
205 | Date: Mon Apr 20 12:30:13 2015 | |
206 | Quorum provider: corosync_votequorum | |
207 | Nodes: 4 | |
208 | Node ID: 0x00000001 | |
209 | Ring ID: 1928 | |
210 | Quorate: Yes | |
211 | ||
212 | Votequorum information | |
213 | ~~~~~~~~~~~~~~~~~~~~~~ | |
214 | Expected votes: 4 | |
215 | Highest expected: 4 | |
216 | Total votes: 4 | |
217 | Quorum: 2 | |
218 | Flags: Quorate | |
219 | ||
220 | Membership information | |
221 | ~~~~~~~~~~~~~~~~~~~~~~ | |
222 | Nodeid Votes Name | |
223 | 0x00000001 1 192.168.15.91 (local) | |
224 | 0x00000002 1 192.168.15.92 | |
225 | 0x00000003 1 192.168.15.93 | |
226 | 0x00000004 1 192.168.15.94 | |
227 | ---- | |
228 | ||
229 | IMPORTANT: at this point you must power off the node to be removed and | |
230 | make sure that it will not power on again (in the network) as it | |
231 | is. | |
232 | ||
233 | ---- | |
234 | hp1# pvecm nodes | |
235 | ||
236 | Membership information | |
237 | ~~~~~~~~~~~~~~~~~~~~~~ | |
238 | Nodeid Votes Name | |
239 | 1 1 hp1 (local) | |
240 | 2 1 hp2 | |
241 | 3 1 hp3 | |
242 | 4 1 hp4 | |
243 | ---- | |
244 | ||
245 | Log in to one remaining node via ssh. Issue the delete command (here | |
8c1189b6 | 246 | deleting node `hp4`): |
8a865621 DM |
247 | |
248 | hp1# pvecm delnode hp4 | |
249 | ||
250 | If the operation succeeds no output is returned, just check the node | |
8c1189b6 | 251 | list again with `pvecm nodes` or `pvecm status`. You should see |
8a865621 DM |
252 | something like: |
253 | ||
254 | ---- | |
255 | hp1# pvecm status | |
256 | ||
257 | Quorum information | |
258 | ~~~~~~~~~~~~~~~~~~ | |
259 | Date: Mon Apr 20 12:44:28 2015 | |
260 | Quorum provider: corosync_votequorum | |
261 | Nodes: 3 | |
262 | Node ID: 0x00000001 | |
263 | Ring ID: 1992 | |
264 | Quorate: Yes | |
265 | ||
266 | Votequorum information | |
267 | ~~~~~~~~~~~~~~~~~~~~~~ | |
268 | Expected votes: 3 | |
269 | Highest expected: 3 | |
270 | Total votes: 3 | |
271 | Quorum: 3 | |
272 | Flags: Quorate | |
273 | ||
274 | Membership information | |
275 | ~~~~~~~~~~~~~~~~~~~~~~ | |
276 | Nodeid Votes Name | |
277 | 0x00000001 1 192.168.15.90 (local) | |
278 | 0x00000002 1 192.168.15.91 | |
279 | 0x00000003 1 192.168.15.92 | |
280 | ---- | |
281 | ||
282 | IMPORTANT: as said above, it is very important to power off the node | |
283 | *before* removal, and make sure that it will *never* power on again | |
284 | (in the existing cluster network) as it is. | |
285 | ||
286 | If you power on the node as it is, your cluster will be screwed up and | |
287 | it could be difficult to restore a clean cluster state. | |
288 | ||
289 | If, for whatever reason, you want that this server joins the same | |
290 | cluster again, you have to | |
291 | ||
26ca7ff5 | 292 | * reinstall {pve} on it from scratch |
8a865621 DM |
293 | |
294 | * then join it, as explained in the previous section. | |
d8742b0c | 295 | |
38ae8db3 | 296 | [[pvecm_separate_node_without_reinstall]] |
555e966b TL |
297 | Separate A Node Without Reinstalling |
298 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
299 | ||
300 | CAUTION: This is *not* the recommended method, proceed with caution. Use the | |
301 | above mentioned method if you're unsure. | |
302 | ||
303 | You can also separate a node from a cluster without reinstalling it from | |
304 | scratch. But after removing the node from the cluster it will still have | |
305 | access to the shared storages! This must be resolved before you start removing | |
306 | the node from the cluster. A {pve} cluster cannot share the exact same | |
307 | storage with another cluster, as it leads to VMID conflicts. | |
308 | ||
3be22308 TL |
309 | Its suggested that you create a new storage where only the node which you want |
310 | to separate has access. This can be an new export on your NFS or a new Ceph | |
311 | pool, to name a few examples. Its just important that the exact same storage | |
312 | does not gets accessed by multiple clusters. After setting this storage up move | |
313 | all data from the node and its VMs to it. Then you are ready to separate the | |
314 | node from the cluster. | |
555e966b TL |
315 | |
316 | WARNING: Ensure all shared resources are cleanly separated! You will run into | |
317 | conflicts and problems else. | |
318 | ||
319 | First stop the corosync and the pve-cluster services on the node: | |
320 | [source,bash] | |
4d19cb00 | 321 | ---- |
555e966b TL |
322 | systemctl stop pve-cluster |
323 | systemctl stop corosync | |
4d19cb00 | 324 | ---- |
555e966b TL |
325 | |
326 | Start the cluster filesystem again in local mode: | |
327 | [source,bash] | |
4d19cb00 | 328 | ---- |
555e966b | 329 | pmxcfs -l |
4d19cb00 | 330 | ---- |
555e966b TL |
331 | |
332 | Delete the corosync configuration files: | |
333 | [source,bash] | |
4d19cb00 | 334 | ---- |
555e966b TL |
335 | rm /etc/pve/corosync.conf |
336 | rm /etc/corosync/* | |
4d19cb00 | 337 | ---- |
555e966b TL |
338 | |
339 | You can now start the filesystem again as normal service: | |
340 | [source,bash] | |
4d19cb00 | 341 | ---- |
555e966b TL |
342 | killall pmxcfs |
343 | systemctl start pve-cluster | |
4d19cb00 | 344 | ---- |
555e966b TL |
345 | |
346 | The node is now separated from the cluster. You can deleted it from a remaining | |
347 | node of the cluster with: | |
348 | [source,bash] | |
4d19cb00 | 349 | ---- |
555e966b | 350 | pvecm delnode oldnode |
4d19cb00 | 351 | ---- |
555e966b TL |
352 | |
353 | If the command failed, because the remaining node in the cluster lost quorum | |
354 | when the now separate node exited, you may set the expected votes to 1 as a workaround: | |
355 | [source,bash] | |
4d19cb00 | 356 | ---- |
555e966b | 357 | pvecm expected 1 |
4d19cb00 | 358 | ---- |
555e966b TL |
359 | |
360 | And the repeat the 'pvecm delnode' command. | |
361 | ||
362 | Now switch back to the separated node, here delete all remaining files left | |
363 | from the old cluster. This ensures that the node can be added to another | |
364 | cluster again without problems. | |
365 | ||
366 | [source,bash] | |
4d19cb00 | 367 | ---- |
555e966b | 368 | rm /var/lib/corosync/* |
4d19cb00 | 369 | ---- |
555e966b TL |
370 | |
371 | As the configuration files from the other nodes are still in the cluster | |
372 | filesystem you may want to clean those up too. Remove simply the whole | |
373 | directory recursive from '/etc/pve/nodes/NODENAME', but check three times that | |
374 | you used the correct one before deleting it. | |
375 | ||
376 | CAUTION: The nodes SSH keys are still in the 'authorized_key' file, this means | |
377 | the nodes can still connect to each other with public key authentication. This | |
378 | should be fixed by removing the respective keys from the | |
379 | '/etc/pve/priv/authorized_keys' file. | |
d8742b0c | 380 | |
806ef12d DM |
381 | Quorum |
382 | ------ | |
383 | ||
384 | {pve} use a quorum-based technique to provide a consistent state among | |
385 | all cluster nodes. | |
386 | ||
387 | [quote, from Wikipedia, Quorum (distributed computing)] | |
388 | ____ | |
389 | A quorum is the minimum number of votes that a distributed transaction | |
390 | has to obtain in order to be allowed to perform an operation in a | |
391 | distributed system. | |
392 | ____ | |
393 | ||
394 | In case of network partitioning, state changes requires that a | |
395 | majority of nodes are online. The cluster switches to read-only mode | |
5eba0743 | 396 | if it loses quorum. |
806ef12d DM |
397 | |
398 | NOTE: {pve} assigns a single vote to each node by default. | |
399 | ||
e4ec4154 TL |
400 | Cluster Network |
401 | --------------- | |
402 | ||
403 | The cluster network is the core of a cluster. All messages sent over it have to | |
404 | be delivered reliable to all nodes in their respective order. In {pve} this | |
405 | part is done by corosync, an implementation of a high performance low overhead | |
406 | high availability development toolkit. It serves our decentralized | |
407 | configuration file system (`pmxcfs`). | |
408 | ||
409 | [[cluster-network-requirements]] | |
410 | Network Requirements | |
411 | ~~~~~~~~~~~~~~~~~~~~ | |
412 | This needs a reliable network with latencies under 2 milliseconds (LAN | |
413 | performance) to work properly. While corosync can also use unicast for | |
414 | communication between nodes its **highly recommended** to have a multicast | |
415 | capable network. The network should not be used heavily by other members, | |
416 | ideally corosync runs on its own network. | |
417 | *never* share it with network where storage communicates too. | |
418 | ||
419 | Before setting up a cluster it is good practice to check if the network is fit | |
420 | for that purpose. | |
421 | ||
422 | * Ensure that all nodes are in the same subnet. This must only be true for the | |
423 | network interfaces used for cluster communication (corosync). | |
424 | ||
425 | * Ensure all nodes can reach each other over those interfaces, using `ping` is | |
426 | enough for a basic test. | |
427 | ||
428 | * Ensure that multicast works in general and a high package rates. This can be | |
429 | done with the `omping` tool. The final "%loss" number should be < 1%. | |
430 | [source,bash] | |
431 | ---- | |
432 | omping -c 10000 -i 0.001 -F -q NODE1-IP NODE2-IP ... | |
433 | ---- | |
434 | ||
435 | * Ensure that multicast communication works over an extended period of time. | |
436 | This covers up problems where IGMP snooping is activated on the network but | |
437 | no multicast querier is active. This test has a duration of around 10 | |
438 | minutes. | |
439 | [source,bash] | |
4d19cb00 | 440 | ---- |
e4ec4154 | 441 | omping -c 600 -i 1 -q NODE1-IP NODE2-IP ... |
4d19cb00 | 442 | ---- |
e4ec4154 TL |
443 | |
444 | Your network is not ready for clustering if any of these test fails. Recheck | |
445 | your network configuration. Especially switches are notorious for having | |
446 | multicast disabled by default or IGMP snooping enabled with no IGMP querier | |
447 | active. | |
448 | ||
449 | In smaller cluster its also an option to use unicast if you really cannot get | |
450 | multicast to work. | |
451 | ||
452 | Separate Cluster Network | |
453 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
454 | ||
455 | When creating a cluster without any parameters the cluster network is generally | |
456 | shared with the Web UI and the VMs and its traffic. Depending on your setup | |
457 | even storage traffic may get sent over the same network. Its recommended to | |
458 | change that, as corosync is a time critical real time application. | |
459 | ||
460 | Setting Up A New Network | |
461 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
462 | ||
463 | First you have to setup a new network interface. It should be on a physical | |
464 | separate network. Ensure that your network fulfills the | |
465 | <<cluster-network-requirements,cluster network requirements>>. | |
466 | ||
467 | Separate On Cluster Creation | |
468 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
469 | ||
470 | This is possible through the 'ring0_addr' and 'bindnet0_addr' parameter of | |
471 | the 'pvecm create' command used for creating a new cluster. | |
472 | ||
473 | If you have setup a additional NIC with a static address on 10.10.10.1/25 | |
474 | and want to send and receive all cluster communication over this interface | |
475 | you would execute: | |
476 | ||
477 | [source,bash] | |
4d19cb00 | 478 | ---- |
e4ec4154 | 479 | pvecm create test --ring0_addr 10.10.10.1 --bindnet0_addr 10.10.10.0 |
4d19cb00 | 480 | ---- |
e4ec4154 TL |
481 | |
482 | To check if everything is working properly execute: | |
483 | [source,bash] | |
4d19cb00 | 484 | ---- |
e4ec4154 | 485 | systemctl status corosync |
4d19cb00 | 486 | ---- |
e4ec4154 TL |
487 | |
488 | [[separate-cluster-net-after-creation]] | |
489 | Separate After Cluster Creation | |
490 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
491 | ||
492 | You can do this also if you have already created a cluster and want to switch | |
493 | its communication to another network, without rebuilding the whole cluster. | |
494 | This change may lead to short durations of quorum loss in the cluster, as nodes | |
495 | have to restart corosync and come up one after the other on the new network. | |
496 | ||
497 | Check how to <<edit-corosync-conf,edit the corosync.conf file>> first. | |
498 | The open it and you should see a file similar to: | |
499 | ||
500 | ---- | |
501 | logging { | |
502 | debug: off | |
503 | to_syslog: yes | |
504 | } | |
505 | ||
506 | nodelist { | |
507 | ||
508 | node { | |
509 | name: due | |
510 | nodeid: 2 | |
511 | quorum_votes: 1 | |
512 | ring0_addr: due | |
513 | } | |
514 | ||
515 | node { | |
516 | name: tre | |
517 | nodeid: 3 | |
518 | quorum_votes: 1 | |
519 | ring0_addr: tre | |
520 | } | |
521 | ||
522 | node { | |
523 | name: uno | |
524 | nodeid: 1 | |
525 | quorum_votes: 1 | |
526 | ring0_addr: uno | |
527 | } | |
528 | ||
529 | } | |
530 | ||
531 | quorum { | |
532 | provider: corosync_votequorum | |
533 | } | |
534 | ||
535 | totem { | |
536 | cluster_name: thomas-testcluster | |
537 | config_version: 3 | |
538 | ip_version: ipv4 | |
539 | secauth: on | |
540 | version: 2 | |
541 | interface { | |
542 | bindnetaddr: 192.168.30.50 | |
543 | ringnumber: 0 | |
544 | } | |
545 | ||
546 | } | |
547 | ---- | |
548 | ||
549 | The first you want to do is add the 'name' properties in the node entries if | |
550 | you do not see them already. Those *must* match the node name. | |
551 | ||
552 | Then replace the address from the 'ring0_addr' properties with the new | |
553 | addresses. You may use plain IP addresses or also hostnames here. If you use | |
554 | hostnames ensure that they are resolvable from all nodes. | |
555 | ||
556 | In my example I want to switch my cluster communication to the 10.10.10.1/25 | |
557 | network. So I replace all 'ring0_addr' respectively. I also set the bindetaddr | |
558 | in the totem section of the config to an address of the new network. It can be | |
559 | any address from the subnet configured on the new network interface. | |
560 | ||
561 | After you increased the 'config_version' property the new configuration file | |
562 | should look like: | |
563 | ||
564 | ---- | |
565 | ||
566 | logging { | |
567 | debug: off | |
568 | to_syslog: yes | |
569 | } | |
570 | ||
571 | nodelist { | |
572 | ||
573 | node { | |
574 | name: due | |
575 | nodeid: 2 | |
576 | quorum_votes: 1 | |
577 | ring0_addr: 10.10.10.2 | |
578 | } | |
579 | ||
580 | node { | |
581 | name: tre | |
582 | nodeid: 3 | |
583 | quorum_votes: 1 | |
584 | ring0_addr: 10.10.10.3 | |
585 | } | |
586 | ||
587 | node { | |
588 | name: uno | |
589 | nodeid: 1 | |
590 | quorum_votes: 1 | |
591 | ring0_addr: 10.10.10.1 | |
592 | } | |
593 | ||
594 | } | |
595 | ||
596 | quorum { | |
597 | provider: corosync_votequorum | |
598 | } | |
599 | ||
600 | totem { | |
601 | cluster_name: thomas-testcluster | |
602 | config_version: 4 | |
603 | ip_version: ipv4 | |
604 | secauth: on | |
605 | version: 2 | |
606 | interface { | |
607 | bindnetaddr: 10.10.10.1 | |
608 | ringnumber: 0 | |
609 | } | |
610 | ||
611 | } | |
612 | ---- | |
613 | ||
614 | Now after a final check whether all changed information is correct we save it | |
615 | and see again the <<edit-corosync-conf,edit corosync.conf file>> section to | |
616 | learn how to bring it in effect. | |
617 | ||
618 | As our change cannot be enforced live from corosync we have to do an restart. | |
619 | ||
620 | On a single node execute: | |
621 | [source,bash] | |
4d19cb00 | 622 | ---- |
e4ec4154 | 623 | systemctl restart corosync |
4d19cb00 | 624 | ---- |
e4ec4154 TL |
625 | |
626 | Now check if everything is fine: | |
627 | ||
628 | [source,bash] | |
4d19cb00 | 629 | ---- |
e4ec4154 | 630 | systemctl status corosync |
4d19cb00 | 631 | ---- |
e4ec4154 TL |
632 | |
633 | If corosync runs again correct restart corosync also on all other nodes. | |
634 | They will then join the cluster membership one by one on the new network. | |
635 | ||
636 | Redundant Ring Protocol | |
637 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
638 | To avoid a single point of failure you should implement counter measurements. | |
639 | This can be on the hardware and operating system level through network bonding. | |
640 | ||
641 | Corosync itself offers also a possibility to add redundancy through the so | |
642 | called 'Redundant Ring Protocol'. This protocol allows running a second totem | |
643 | ring on another network, this network should be physically separated from the | |
644 | other rings network to actually increase availability. | |
645 | ||
646 | RRP On Cluster Creation | |
647 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
648 | ||
649 | The 'pvecm create' command provides the additional parameters 'bindnetX_addr', | |
650 | 'ringX_addr' and 'rrp_mode', can be used for RRP configuration. | |
651 | ||
652 | NOTE: See the <<corosync-conf-glossary,glossary>> if you do not know what each parameter means. | |
653 | ||
654 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
655 | 10.10.20.1/24 subnet you would execute: | |
656 | ||
657 | [source,bash] | |
4d19cb00 | 658 | ---- |
e4ec4154 TL |
659 | pvecm create CLUSTERNAME -bindnet0_addr 10.10.10.1 -ring0_addr 10.10.10.1 \ |
660 | -bindnet1_addr 10.10.20.1 -ring1_addr 10.10.20.1 | |
4d19cb00 | 661 | ---- |
e4ec4154 TL |
662 | |
663 | RRP On A Created Cluster | |
664 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
665 | ||
666 | When enabling an already running cluster to use RRP you will take similar steps | |
7d48940b DM |
667 | as describe in |
668 | <<separate-cluster-net-after-creation,separating the cluster network>>. You | |
669 | just do it on another ring. | |
e4ec4154 TL |
670 | |
671 | First add a new `interface` subsection in the `totem` section, set its | |
672 | `ringnumber` property to `1`. Set the interfaces `bindnetaddr` property to an | |
673 | address of the subnet you have configured for your new ring. | |
674 | Further set the `rrp_mode` to `passive`, this is the only stable mode. | |
675 | ||
676 | Then add to each node entry in the `nodelist` section its new `ring1_addr` | |
677 | property with the nodes additional ring address. | |
678 | ||
679 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
680 | 10.10.20.1/24 subnet, the final configuration file should look like: | |
681 | ||
682 | ---- | |
683 | totem { | |
684 | cluster_name: tweak | |
685 | config_version: 9 | |
686 | ip_version: ipv4 | |
687 | rrp_mode: passive | |
688 | secauth: on | |
689 | version: 2 | |
690 | interface { | |
691 | bindnetaddr: 10.10.10.1 | |
692 | ringnumber: 0 | |
693 | } | |
694 | interface { | |
695 | bindnetaddr: 10.10.20.1 | |
696 | ringnumber: 1 | |
697 | } | |
698 | } | |
699 | ||
700 | nodelist { | |
701 | node { | |
702 | name: pvecm1 | |
703 | nodeid: 1 | |
704 | quorum_votes: 1 | |
705 | ring0_addr: 10.10.10.1 | |
706 | ring1_addr: 10.10.20.1 | |
707 | } | |
708 | ||
709 | node { | |
710 | name: pvecm2 | |
711 | nodeid: 2 | |
712 | quorum_votes: 1 | |
713 | ring0_addr: 10.10.10.2 | |
714 | ring1_addr: 10.10.20.2 | |
715 | } | |
716 | ||
717 | [...] # other cluster nodes here | |
718 | } | |
719 | ||
720 | [...] # other remaining config sections here | |
721 | ||
722 | ---- | |
723 | ||
7d48940b DM |
724 | Bring it in effect like described in the |
725 | <<edit-corosync-conf,edit the corosync.conf file>> section. | |
e4ec4154 TL |
726 | |
727 | This is a change which cannot take live in effect and needs at least a restart | |
728 | of corosync. Recommended is a restart of the whole cluster. | |
729 | ||
730 | If you cannot reboot the whole cluster ensure no High Availability services are | |
731 | configured and the stop the corosync service on all nodes. After corosync is | |
732 | stopped on all nodes start it one after the other again. | |
733 | ||
734 | Corosync Configuration | |
735 | ---------------------- | |
736 | ||
737 | The `/ect/pve/corosync.conf` file plays a central role in {pve} cluster. It | |
738 | controls the cluster member ship and its network. | |
739 | For reading more about it check the corosync.conf man page: | |
740 | [source,bash] | |
4d19cb00 | 741 | ---- |
e4ec4154 | 742 | man corosync.conf |
4d19cb00 | 743 | ---- |
e4ec4154 TL |
744 | |
745 | For node membership you should always use the `pvecm` tool provided by {pve}. | |
746 | You may have to edit the configuration file manually for other changes. | |
747 | Here are a few best practice tips for doing this. | |
748 | ||
749 | [[edit-corosync-conf]] | |
750 | Edit corosync.conf | |
751 | ~~~~~~~~~~~~~~~~~~ | |
752 | ||
753 | Editing the corosync.conf file can be not always straight forward. There are | |
754 | two on each cluster, one in `/etc/pve/corosync.conf` and the other in | |
755 | `/etc/corosync/corosync.conf`. Editing the one in our cluster file system will | |
756 | propagate the changes to the local one, but not vice versa. | |
757 | ||
758 | The configuration will get updated automatically as soon as the file changes. | |
759 | This means changes which can be integrated in a running corosync will take | |
760 | instantly effect. So you should always make a copy and edit that instead, to | |
761 | avoid triggering some unwanted changes by an in between safe. | |
762 | ||
763 | [source,bash] | |
4d19cb00 | 764 | ---- |
e4ec4154 | 765 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.new |
4d19cb00 | 766 | ---- |
e4ec4154 TL |
767 | |
768 | Then open the Config file with your favorite editor, `nano` and `vim.tiny` are | |
769 | preinstalled on {pve} for example. | |
770 | ||
771 | NOTE: Always increment the 'config_version' number on configuration changes, | |
772 | omitting this can lead to problems. | |
773 | ||
774 | After making the necessary changes create another copy of the current working | |
775 | configuration file. This serves as a backup if the new configuration fails to | |
776 | apply or makes problems in other ways. | |
777 | ||
778 | [source,bash] | |
4d19cb00 | 779 | ---- |
e4ec4154 | 780 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.bak |
4d19cb00 | 781 | ---- |
e4ec4154 TL |
782 | |
783 | Then move the new configuration file over the old one: | |
784 | [source,bash] | |
4d19cb00 | 785 | ---- |
e4ec4154 | 786 | mv /etc/pve/corosync.conf.new /etc/pve/corosync.conf |
4d19cb00 | 787 | ---- |
e4ec4154 TL |
788 | |
789 | You may check with the commands | |
790 | [source,bash] | |
4d19cb00 | 791 | ---- |
e4ec4154 TL |
792 | systemctl status corosync |
793 | journalctl -b -u corosync | |
4d19cb00 | 794 | ---- |
e4ec4154 TL |
795 | |
796 | If the change could applied automatically. If not you may have to restart the | |
797 | corosync service via: | |
798 | [source,bash] | |
4d19cb00 | 799 | ---- |
e4ec4154 | 800 | systemctl restart corosync |
4d19cb00 | 801 | ---- |
e4ec4154 TL |
802 | |
803 | On errors check the troubleshooting section below. | |
804 | ||
805 | Troubleshooting | |
806 | ~~~~~~~~~~~~~~~ | |
807 | ||
808 | Issue: 'quorum.expected_votes must be configured' | |
809 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
810 | ||
811 | When corosync starts to fail and you get the following message in the system log: | |
812 | ||
813 | ---- | |
814 | [...] | |
815 | corosync[1647]: [QUORUM] Quorum provider: corosync_votequorum failed to initialize. | |
816 | corosync[1647]: [SERV ] Service engine 'corosync_quorum' failed to load for reason | |
817 | 'configuration error: nodelist or quorum.expected_votes must be configured!' | |
818 | [...] | |
819 | ---- | |
820 | ||
821 | It means that the hostname you set for corosync 'ringX_addr' in the | |
822 | configuration could not be resolved. | |
823 | ||
824 | ||
825 | Write Configuration When Not Quorate | |
826 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
827 | ||
828 | If you need to change '/etc/pve/corosync.conf' on an node with no quorum, and you | |
829 | know what you do, use: | |
830 | [source,bash] | |
4d19cb00 | 831 | ---- |
e4ec4154 | 832 | pvecm expected 1 |
4d19cb00 | 833 | ---- |
e4ec4154 TL |
834 | |
835 | This sets the expected vote count to 1 and makes the cluster quorate. You can | |
836 | now fix your configuration, or revert it back to the last working backup. | |
837 | ||
838 | This is not enough if corosync cannot start anymore. Here its best to edit the | |
839 | local copy of the corosync configuration in '/etc/corosync/corosync.conf' so | |
840 | that corosync can start again. Ensure that on all nodes this configuration has | |
841 | the same content to avoid split brains. If you are not sure what went wrong | |
842 | it's best to ask the Proxmox Community to help you. | |
843 | ||
844 | ||
845 | [[corosync-conf-glossary]] | |
846 | Corosync Configuration Glossary | |
847 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
848 | ||
849 | ringX_addr:: | |
850 | This names the different ring addresses for the corosync totem rings used for | |
851 | the cluster communication. | |
852 | ||
853 | bindnetaddr:: | |
854 | Defines to which interface the ring should bind to. It may be any address of | |
855 | the subnet configured on the interface we want to use. In general its the | |
856 | recommended to just use an address a node uses on this interface. | |
857 | ||
858 | rrp_mode:: | |
859 | Specifies the mode of the redundant ring protocol and may be passive, active or | |
860 | none. Note that use of active is highly experimental and not official | |
861 | supported. Passive is the preferred mode, it may double the cluster | |
862 | communication throughput and increases availability. | |
863 | ||
806ef12d DM |
864 | |
865 | Cluster Cold Start | |
866 | ------------------ | |
867 | ||
868 | It is obvious that a cluster is not quorate when all nodes are | |
869 | offline. This is a common case after a power failure. | |
870 | ||
871 | NOTE: It is always a good idea to use an uninterruptible power supply | |
8c1189b6 | 872 | (``UPS'', also called ``battery backup'') to avoid this state, especially if |
806ef12d DM |
873 | you want HA. |
874 | ||
8c1189b6 FG |
875 | On node startup, service `pve-manager` is started and waits for |
876 | quorum. Once quorate, it starts all guests which have the `onboot` | |
612417fd DM |
877 | flag set. |
878 | ||
879 | When you turn on nodes, or when power comes back after power failure, | |
880 | it is likely that some nodes boots faster than others. Please keep in | |
881 | mind that guest startup is delayed until you reach quorum. | |
806ef12d | 882 | |
054a7e7d | 883 | |
082ea7d9 TL |
884 | Guest Migration |
885 | --------------- | |
886 | ||
054a7e7d DM |
887 | Migrating virtual guests to other nodes is a useful feature in a |
888 | cluster. There are settings to control the behavior of such | |
889 | migrations. This can be done via the configuration file | |
890 | `datacenter.cfg` or for a specific migration via API or command line | |
891 | parameters. | |
892 | ||
082ea7d9 TL |
893 | |
894 | Migration Type | |
895 | ~~~~~~~~~~~~~~ | |
896 | ||
897 | The migration type defines if the migration data should be sent over a | |
d63be10b | 898 | encrypted (`secure`) channel or an unencrypted (`insecure`) one. |
082ea7d9 | 899 | Setting the migration type to insecure means that the RAM content of a |
b1743473 DM |
900 | virtual guest gets also transfered unencrypted, which can lead to |
901 | information disclosure of critical data from inside the guest (for | |
902 | example passwords or encryption keys). | |
054a7e7d DM |
903 | |
904 | Therefore, we strongly recommend using the secure channel if you do | |
905 | not have full control over the network and can not guarantee that no | |
906 | one is eavesdropping to it. | |
082ea7d9 | 907 | |
054a7e7d DM |
908 | NOTE: Storage migration does not follow this setting. Currently, it |
909 | always sends the storage content over a secure channel. | |
910 | ||
911 | Encryption requires a lot of computing power, so this setting is often | |
912 | changed to "unsafe" to achieve better performance. The impact on | |
913 | modern systems is lower because they implement AES encryption in | |
b1743473 DM |
914 | hardware. The performance impact is particularly evident in fast |
915 | networks where you can transfer 10 Gbps or more. | |
082ea7d9 | 916 | |
082ea7d9 TL |
917 | |
918 | Migration Network | |
919 | ~~~~~~~~~~~~~~~~~ | |
920 | ||
a9baa444 TL |
921 | By default, {pve} uses the network in which cluster communication |
922 | takes place to send the migration traffic. This is not optimal because | |
923 | sensitive cluster traffic can be disrupted and this network may not | |
924 | have the best bandwidth available on the node. | |
925 | ||
926 | Setting the migration network parameter allows the use of a dedicated | |
927 | network for the entire migration traffic. In addition to the memory, | |
928 | this also affects the storage traffic for offline migrations. | |
929 | ||
930 | The migration network is set as a network in the CIDR notation. This | |
931 | has the advantage that you do not have to set individual IP addresses | |
932 | for each node. {pve} can determine the real address on the | |
933 | destination node from the network specified in the CIDR form. To | |
934 | enable this, the network must be specified so that each node has one, | |
935 | but only one IP in the respective network. | |
936 | ||
082ea7d9 TL |
937 | |
938 | Example | |
939 | ^^^^^^^ | |
940 | ||
a9baa444 TL |
941 | We assume that we have a three-node setup with three separate |
942 | networks. One for public communication with the Internet, one for | |
943 | cluster communication and a very fast one, which we want to use as a | |
944 | dedicated network for migration. | |
945 | ||
946 | A network configuration for such a setup might look as follows: | |
082ea7d9 TL |
947 | |
948 | ---- | |
949 | iface eth0 inet manual | |
950 | ||
951 | # public network | |
952 | auto vmbr0 | |
953 | iface vmbr0 inet static | |
954 | address 192.X.Y.57 | |
955 | netmask 255.255.250.0 | |
956 | gateway 192.X.Y.1 | |
957 | bridge_ports eth0 | |
958 | bridge_stp off | |
959 | bridge_fd 0 | |
960 | ||
961 | # cluster network | |
962 | auto eth1 | |
963 | iface eth1 inet static | |
964 | address 10.1.1.1 | |
965 | netmask 255.255.255.0 | |
966 | ||
967 | # fast network | |
968 | auto eth2 | |
969 | iface eth2 inet static | |
970 | address 10.1.2.1 | |
971 | netmask 255.255.255.0 | |
082ea7d9 TL |
972 | ---- |
973 | ||
a9baa444 TL |
974 | Here, we will use the network 10.1.2.0/24 as a migration network. For |
975 | a single migration, you can do this using the `migration_network` | |
976 | parameter of the command line tool: | |
977 | ||
082ea7d9 | 978 | ---- |
b1743473 | 979 | # qm migrate 106 tre --online --migration_network 10.1.2.0/24 |
082ea7d9 TL |
980 | ---- |
981 | ||
a9baa444 TL |
982 | To configure this as the default network for all migrations in the |
983 | cluster, set the `migration` property of the `/etc/pve/datacenter.cfg` | |
984 | file: | |
985 | ||
082ea7d9 | 986 | ---- |
a9baa444 | 987 | # use dedicated migration network |
b1743473 | 988 | migration: secure,network=10.1.2.0/24 |
082ea7d9 TL |
989 | ---- |
990 | ||
a9baa444 TL |
991 | NOTE: The migration type must always be set when the migration network |
992 | gets set in `/etc/pve/datacenter.cfg`. | |
993 | ||
806ef12d | 994 | |
d8742b0c DM |
995 | ifdef::manvolnum[] |
996 | include::pve-copyright.adoc[] | |
997 | endif::manvolnum[] |