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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. | |
e8503c6c | 196 | In the following example we will remove the node hp4 from the cluster. |
8a865621 | 197 | |
e8503c6c EK |
198 | Log in to a *different* cluster node (not hp4), and issue a `pvecm nodes` |
199 | command to identify the node ID to remove: | |
8a865621 DM |
200 | |
201 | ---- | |
202 | hp1# pvecm nodes | |
203 | ||
204 | Membership information | |
205 | ~~~~~~~~~~~~~~~~~~~~~~ | |
206 | Nodeid Votes Name | |
207 | 1 1 hp1 (local) | |
208 | 2 1 hp2 | |
209 | 3 1 hp3 | |
210 | 4 1 hp4 | |
211 | ---- | |
212 | ||
e8503c6c EK |
213 | |
214 | At this point you must power off hp4 and | |
215 | make sure that it will not power on again (in the network) as it | |
216 | is. | |
217 | ||
218 | IMPORTANT: As said above, it is critical to power off the node | |
219 | *before* removal, and make sure that it will *never* power on again | |
220 | (in the existing cluster network) as it is. | |
221 | If you power on the node as it is, your cluster will be screwed up and | |
222 | it could be difficult to restore a clean cluster state. | |
223 | ||
224 | After powering off the node hp4, we can safely remove it from the cluster. | |
8a865621 DM |
225 | |
226 | hp1# pvecm delnode hp4 | |
227 | ||
228 | If the operation succeeds no output is returned, just check the node | |
8c1189b6 | 229 | list again with `pvecm nodes` or `pvecm status`. You should see |
8a865621 DM |
230 | something like: |
231 | ||
232 | ---- | |
233 | hp1# pvecm status | |
234 | ||
235 | Quorum information | |
236 | ~~~~~~~~~~~~~~~~~~ | |
237 | Date: Mon Apr 20 12:44:28 2015 | |
238 | Quorum provider: corosync_votequorum | |
239 | Nodes: 3 | |
240 | Node ID: 0x00000001 | |
241 | Ring ID: 1992 | |
242 | Quorate: Yes | |
243 | ||
244 | Votequorum information | |
245 | ~~~~~~~~~~~~~~~~~~~~~~ | |
246 | Expected votes: 3 | |
247 | Highest expected: 3 | |
248 | Total votes: 3 | |
249 | Quorum: 3 | |
250 | Flags: Quorate | |
251 | ||
252 | Membership information | |
253 | ~~~~~~~~~~~~~~~~~~~~~~ | |
254 | Nodeid Votes Name | |
255 | 0x00000001 1 192.168.15.90 (local) | |
256 | 0x00000002 1 192.168.15.91 | |
257 | 0x00000003 1 192.168.15.92 | |
258 | ---- | |
259 | ||
8a865621 DM |
260 | If, for whatever reason, you want that this server joins the same |
261 | cluster again, you have to | |
262 | ||
26ca7ff5 | 263 | * reinstall {pve} on it from scratch |
8a865621 DM |
264 | |
265 | * then join it, as explained in the previous section. | |
d8742b0c | 266 | |
38ae8db3 | 267 | [[pvecm_separate_node_without_reinstall]] |
555e966b TL |
268 | Separate A Node Without Reinstalling |
269 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
270 | ||
271 | CAUTION: This is *not* the recommended method, proceed with caution. Use the | |
272 | above mentioned method if you're unsure. | |
273 | ||
274 | You can also separate a node from a cluster without reinstalling it from | |
275 | scratch. But after removing the node from the cluster it will still have | |
276 | access to the shared storages! This must be resolved before you start removing | |
277 | the node from the cluster. A {pve} cluster cannot share the exact same | |
278 | storage with another cluster, as it leads to VMID conflicts. | |
279 | ||
3be22308 TL |
280 | Its suggested that you create a new storage where only the node which you want |
281 | to separate has access. This can be an new export on your NFS or a new Ceph | |
282 | pool, to name a few examples. Its just important that the exact same storage | |
283 | does not gets accessed by multiple clusters. After setting this storage up move | |
284 | all data from the node and its VMs to it. Then you are ready to separate the | |
285 | node from the cluster. | |
555e966b TL |
286 | |
287 | WARNING: Ensure all shared resources are cleanly separated! You will run into | |
288 | conflicts and problems else. | |
289 | ||
290 | First stop the corosync and the pve-cluster services on the node: | |
291 | [source,bash] | |
4d19cb00 | 292 | ---- |
555e966b TL |
293 | systemctl stop pve-cluster |
294 | systemctl stop corosync | |
4d19cb00 | 295 | ---- |
555e966b TL |
296 | |
297 | Start the cluster filesystem again in local mode: | |
298 | [source,bash] | |
4d19cb00 | 299 | ---- |
555e966b | 300 | pmxcfs -l |
4d19cb00 | 301 | ---- |
555e966b TL |
302 | |
303 | Delete the corosync configuration files: | |
304 | [source,bash] | |
4d19cb00 | 305 | ---- |
555e966b TL |
306 | rm /etc/pve/corosync.conf |
307 | rm /etc/corosync/* | |
4d19cb00 | 308 | ---- |
555e966b TL |
309 | |
310 | You can now start the filesystem again as normal service: | |
311 | [source,bash] | |
4d19cb00 | 312 | ---- |
555e966b TL |
313 | killall pmxcfs |
314 | systemctl start pve-cluster | |
4d19cb00 | 315 | ---- |
555e966b TL |
316 | |
317 | The node is now separated from the cluster. You can deleted it from a remaining | |
318 | node of the cluster with: | |
319 | [source,bash] | |
4d19cb00 | 320 | ---- |
555e966b | 321 | pvecm delnode oldnode |
4d19cb00 | 322 | ---- |
555e966b TL |
323 | |
324 | If the command failed, because the remaining node in the cluster lost quorum | |
325 | when the now separate node exited, you may set the expected votes to 1 as a workaround: | |
326 | [source,bash] | |
4d19cb00 | 327 | ---- |
555e966b | 328 | pvecm expected 1 |
4d19cb00 | 329 | ---- |
555e966b TL |
330 | |
331 | And the repeat the 'pvecm delnode' command. | |
332 | ||
333 | Now switch back to the separated node, here delete all remaining files left | |
334 | from the old cluster. This ensures that the node can be added to another | |
335 | cluster again without problems. | |
336 | ||
337 | [source,bash] | |
4d19cb00 | 338 | ---- |
555e966b | 339 | rm /var/lib/corosync/* |
4d19cb00 | 340 | ---- |
555e966b TL |
341 | |
342 | As the configuration files from the other nodes are still in the cluster | |
343 | filesystem you may want to clean those up too. Remove simply the whole | |
344 | directory recursive from '/etc/pve/nodes/NODENAME', but check three times that | |
345 | you used the correct one before deleting it. | |
346 | ||
347 | CAUTION: The nodes SSH keys are still in the 'authorized_key' file, this means | |
348 | the nodes can still connect to each other with public key authentication. This | |
349 | should be fixed by removing the respective keys from the | |
350 | '/etc/pve/priv/authorized_keys' file. | |
d8742b0c | 351 | |
806ef12d DM |
352 | Quorum |
353 | ------ | |
354 | ||
355 | {pve} use a quorum-based technique to provide a consistent state among | |
356 | all cluster nodes. | |
357 | ||
358 | [quote, from Wikipedia, Quorum (distributed computing)] | |
359 | ____ | |
360 | A quorum is the minimum number of votes that a distributed transaction | |
361 | has to obtain in order to be allowed to perform an operation in a | |
362 | distributed system. | |
363 | ____ | |
364 | ||
365 | In case of network partitioning, state changes requires that a | |
366 | majority of nodes are online. The cluster switches to read-only mode | |
5eba0743 | 367 | if it loses quorum. |
806ef12d DM |
368 | |
369 | NOTE: {pve} assigns a single vote to each node by default. | |
370 | ||
e4ec4154 TL |
371 | Cluster Network |
372 | --------------- | |
373 | ||
374 | The cluster network is the core of a cluster. All messages sent over it have to | |
375 | be delivered reliable to all nodes in their respective order. In {pve} this | |
376 | part is done by corosync, an implementation of a high performance low overhead | |
377 | high availability development toolkit. It serves our decentralized | |
378 | configuration file system (`pmxcfs`). | |
379 | ||
380 | [[cluster-network-requirements]] | |
381 | Network Requirements | |
382 | ~~~~~~~~~~~~~~~~~~~~ | |
383 | This needs a reliable network with latencies under 2 milliseconds (LAN | |
384 | performance) to work properly. While corosync can also use unicast for | |
385 | communication between nodes its **highly recommended** to have a multicast | |
386 | capable network. The network should not be used heavily by other members, | |
387 | ideally corosync runs on its own network. | |
388 | *never* share it with network where storage communicates too. | |
389 | ||
390 | Before setting up a cluster it is good practice to check if the network is fit | |
391 | for that purpose. | |
392 | ||
393 | * Ensure that all nodes are in the same subnet. This must only be true for the | |
394 | network interfaces used for cluster communication (corosync). | |
395 | ||
396 | * Ensure all nodes can reach each other over those interfaces, using `ping` is | |
397 | enough for a basic test. | |
398 | ||
399 | * Ensure that multicast works in general and a high package rates. This can be | |
400 | done with the `omping` tool. The final "%loss" number should be < 1%. | |
401 | [source,bash] | |
402 | ---- | |
403 | omping -c 10000 -i 0.001 -F -q NODE1-IP NODE2-IP ... | |
404 | ---- | |
405 | ||
406 | * Ensure that multicast communication works over an extended period of time. | |
407 | This covers up problems where IGMP snooping is activated on the network but | |
408 | no multicast querier is active. This test has a duration of around 10 | |
409 | minutes. | |
410 | [source,bash] | |
4d19cb00 | 411 | ---- |
e4ec4154 | 412 | omping -c 600 -i 1 -q NODE1-IP NODE2-IP ... |
4d19cb00 | 413 | ---- |
e4ec4154 TL |
414 | |
415 | Your network is not ready for clustering if any of these test fails. Recheck | |
416 | your network configuration. Especially switches are notorious for having | |
417 | multicast disabled by default or IGMP snooping enabled with no IGMP querier | |
418 | active. | |
419 | ||
420 | In smaller cluster its also an option to use unicast if you really cannot get | |
421 | multicast to work. | |
422 | ||
423 | Separate Cluster Network | |
424 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
425 | ||
426 | When creating a cluster without any parameters the cluster network is generally | |
427 | shared with the Web UI and the VMs and its traffic. Depending on your setup | |
428 | even storage traffic may get sent over the same network. Its recommended to | |
429 | change that, as corosync is a time critical real time application. | |
430 | ||
431 | Setting Up A New Network | |
432 | ^^^^^^^^^^^^^^^^^^^^^^^^ | |
433 | ||
434 | First you have to setup a new network interface. It should be on a physical | |
435 | separate network. Ensure that your network fulfills the | |
436 | <<cluster-network-requirements,cluster network requirements>>. | |
437 | ||
438 | Separate On Cluster Creation | |
439 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
440 | ||
441 | This is possible through the 'ring0_addr' and 'bindnet0_addr' parameter of | |
442 | the 'pvecm create' command used for creating a new cluster. | |
443 | ||
444 | If you have setup a additional NIC with a static address on 10.10.10.1/25 | |
445 | and want to send and receive all cluster communication over this interface | |
446 | you would execute: | |
447 | ||
448 | [source,bash] | |
4d19cb00 | 449 | ---- |
e4ec4154 | 450 | pvecm create test --ring0_addr 10.10.10.1 --bindnet0_addr 10.10.10.0 |
4d19cb00 | 451 | ---- |
e4ec4154 TL |
452 | |
453 | To check if everything is working properly execute: | |
454 | [source,bash] | |
4d19cb00 | 455 | ---- |
e4ec4154 | 456 | systemctl status corosync |
4d19cb00 | 457 | ---- |
e4ec4154 TL |
458 | |
459 | [[separate-cluster-net-after-creation]] | |
460 | Separate After Cluster Creation | |
461 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
462 | ||
463 | You can do this also if you have already created a cluster and want to switch | |
464 | its communication to another network, without rebuilding the whole cluster. | |
465 | This change may lead to short durations of quorum loss in the cluster, as nodes | |
466 | have to restart corosync and come up one after the other on the new network. | |
467 | ||
468 | Check how to <<edit-corosync-conf,edit the corosync.conf file>> first. | |
469 | The open it and you should see a file similar to: | |
470 | ||
471 | ---- | |
472 | logging { | |
473 | debug: off | |
474 | to_syslog: yes | |
475 | } | |
476 | ||
477 | nodelist { | |
478 | ||
479 | node { | |
480 | name: due | |
481 | nodeid: 2 | |
482 | quorum_votes: 1 | |
483 | ring0_addr: due | |
484 | } | |
485 | ||
486 | node { | |
487 | name: tre | |
488 | nodeid: 3 | |
489 | quorum_votes: 1 | |
490 | ring0_addr: tre | |
491 | } | |
492 | ||
493 | node { | |
494 | name: uno | |
495 | nodeid: 1 | |
496 | quorum_votes: 1 | |
497 | ring0_addr: uno | |
498 | } | |
499 | ||
500 | } | |
501 | ||
502 | quorum { | |
503 | provider: corosync_votequorum | |
504 | } | |
505 | ||
506 | totem { | |
507 | cluster_name: thomas-testcluster | |
508 | config_version: 3 | |
509 | ip_version: ipv4 | |
510 | secauth: on | |
511 | version: 2 | |
512 | interface { | |
513 | bindnetaddr: 192.168.30.50 | |
514 | ringnumber: 0 | |
515 | } | |
516 | ||
517 | } | |
518 | ---- | |
519 | ||
520 | The first you want to do is add the 'name' properties in the node entries if | |
521 | you do not see them already. Those *must* match the node name. | |
522 | ||
523 | Then replace the address from the 'ring0_addr' properties with the new | |
524 | addresses. You may use plain IP addresses or also hostnames here. If you use | |
525 | hostnames ensure that they are resolvable from all nodes. | |
526 | ||
527 | In my example I want to switch my cluster communication to the 10.10.10.1/25 | |
528 | network. So I replace all 'ring0_addr' respectively. I also set the bindetaddr | |
529 | in the totem section of the config to an address of the new network. It can be | |
530 | any address from the subnet configured on the new network interface. | |
531 | ||
532 | After you increased the 'config_version' property the new configuration file | |
533 | should look like: | |
534 | ||
535 | ---- | |
536 | ||
537 | logging { | |
538 | debug: off | |
539 | to_syslog: yes | |
540 | } | |
541 | ||
542 | nodelist { | |
543 | ||
544 | node { | |
545 | name: due | |
546 | nodeid: 2 | |
547 | quorum_votes: 1 | |
548 | ring0_addr: 10.10.10.2 | |
549 | } | |
550 | ||
551 | node { | |
552 | name: tre | |
553 | nodeid: 3 | |
554 | quorum_votes: 1 | |
555 | ring0_addr: 10.10.10.3 | |
556 | } | |
557 | ||
558 | node { | |
559 | name: uno | |
560 | nodeid: 1 | |
561 | quorum_votes: 1 | |
562 | ring0_addr: 10.10.10.1 | |
563 | } | |
564 | ||
565 | } | |
566 | ||
567 | quorum { | |
568 | provider: corosync_votequorum | |
569 | } | |
570 | ||
571 | totem { | |
572 | cluster_name: thomas-testcluster | |
573 | config_version: 4 | |
574 | ip_version: ipv4 | |
575 | secauth: on | |
576 | version: 2 | |
577 | interface { | |
578 | bindnetaddr: 10.10.10.1 | |
579 | ringnumber: 0 | |
580 | } | |
581 | ||
582 | } | |
583 | ---- | |
584 | ||
585 | Now after a final check whether all changed information is correct we save it | |
586 | and see again the <<edit-corosync-conf,edit corosync.conf file>> section to | |
587 | learn how to bring it in effect. | |
588 | ||
589 | As our change cannot be enforced live from corosync we have to do an restart. | |
590 | ||
591 | On a single node execute: | |
592 | [source,bash] | |
4d19cb00 | 593 | ---- |
e4ec4154 | 594 | systemctl restart corosync |
4d19cb00 | 595 | ---- |
e4ec4154 TL |
596 | |
597 | Now check if everything is fine: | |
598 | ||
599 | [source,bash] | |
4d19cb00 | 600 | ---- |
e4ec4154 | 601 | systemctl status corosync |
4d19cb00 | 602 | ---- |
e4ec4154 TL |
603 | |
604 | If corosync runs again correct restart corosync also on all other nodes. | |
605 | They will then join the cluster membership one by one on the new network. | |
606 | ||
607 | Redundant Ring Protocol | |
608 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
609 | To avoid a single point of failure you should implement counter measurements. | |
610 | This can be on the hardware and operating system level through network bonding. | |
611 | ||
612 | Corosync itself offers also a possibility to add redundancy through the so | |
613 | called 'Redundant Ring Protocol'. This protocol allows running a second totem | |
614 | ring on another network, this network should be physically separated from the | |
615 | other rings network to actually increase availability. | |
616 | ||
617 | RRP On Cluster Creation | |
618 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
619 | ||
620 | The 'pvecm create' command provides the additional parameters 'bindnetX_addr', | |
621 | 'ringX_addr' and 'rrp_mode', can be used for RRP configuration. | |
622 | ||
623 | NOTE: See the <<corosync-conf-glossary,glossary>> if you do not know what each parameter means. | |
624 | ||
625 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
626 | 10.10.20.1/24 subnet you would execute: | |
627 | ||
628 | [source,bash] | |
4d19cb00 | 629 | ---- |
e4ec4154 TL |
630 | pvecm create CLUSTERNAME -bindnet0_addr 10.10.10.1 -ring0_addr 10.10.10.1 \ |
631 | -bindnet1_addr 10.10.20.1 -ring1_addr 10.10.20.1 | |
4d19cb00 | 632 | ---- |
e4ec4154 TL |
633 | |
634 | RRP On A Created Cluster | |
635 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
636 | ||
637 | When enabling an already running cluster to use RRP you will take similar steps | |
7d48940b DM |
638 | as describe in |
639 | <<separate-cluster-net-after-creation,separating the cluster network>>. You | |
640 | just do it on another ring. | |
e4ec4154 TL |
641 | |
642 | First add a new `interface` subsection in the `totem` section, set its | |
643 | `ringnumber` property to `1`. Set the interfaces `bindnetaddr` property to an | |
644 | address of the subnet you have configured for your new ring. | |
645 | Further set the `rrp_mode` to `passive`, this is the only stable mode. | |
646 | ||
647 | Then add to each node entry in the `nodelist` section its new `ring1_addr` | |
648 | property with the nodes additional ring address. | |
649 | ||
650 | So if you have two networks, one on the 10.10.10.1/24 and the other on the | |
651 | 10.10.20.1/24 subnet, the final configuration file should look like: | |
652 | ||
653 | ---- | |
654 | totem { | |
655 | cluster_name: tweak | |
656 | config_version: 9 | |
657 | ip_version: ipv4 | |
658 | rrp_mode: passive | |
659 | secauth: on | |
660 | version: 2 | |
661 | interface { | |
662 | bindnetaddr: 10.10.10.1 | |
663 | ringnumber: 0 | |
664 | } | |
665 | interface { | |
666 | bindnetaddr: 10.10.20.1 | |
667 | ringnumber: 1 | |
668 | } | |
669 | } | |
670 | ||
671 | nodelist { | |
672 | node { | |
673 | name: pvecm1 | |
674 | nodeid: 1 | |
675 | quorum_votes: 1 | |
676 | ring0_addr: 10.10.10.1 | |
677 | ring1_addr: 10.10.20.1 | |
678 | } | |
679 | ||
680 | node { | |
681 | name: pvecm2 | |
682 | nodeid: 2 | |
683 | quorum_votes: 1 | |
684 | ring0_addr: 10.10.10.2 | |
685 | ring1_addr: 10.10.20.2 | |
686 | } | |
687 | ||
688 | [...] # other cluster nodes here | |
689 | } | |
690 | ||
691 | [...] # other remaining config sections here | |
692 | ||
693 | ---- | |
694 | ||
7d48940b DM |
695 | Bring it in effect like described in the |
696 | <<edit-corosync-conf,edit the corosync.conf file>> section. | |
e4ec4154 TL |
697 | |
698 | This is a change which cannot take live in effect and needs at least a restart | |
699 | of corosync. Recommended is a restart of the whole cluster. | |
700 | ||
701 | If you cannot reboot the whole cluster ensure no High Availability services are | |
702 | configured and the stop the corosync service on all nodes. After corosync is | |
703 | stopped on all nodes start it one after the other again. | |
704 | ||
705 | Corosync Configuration | |
706 | ---------------------- | |
707 | ||
708 | The `/ect/pve/corosync.conf` file plays a central role in {pve} cluster. It | |
709 | controls the cluster member ship and its network. | |
710 | For reading more about it check the corosync.conf man page: | |
711 | [source,bash] | |
4d19cb00 | 712 | ---- |
e4ec4154 | 713 | man corosync.conf |
4d19cb00 | 714 | ---- |
e4ec4154 TL |
715 | |
716 | For node membership you should always use the `pvecm` tool provided by {pve}. | |
717 | You may have to edit the configuration file manually for other changes. | |
718 | Here are a few best practice tips for doing this. | |
719 | ||
720 | [[edit-corosync-conf]] | |
721 | Edit corosync.conf | |
722 | ~~~~~~~~~~~~~~~~~~ | |
723 | ||
724 | Editing the corosync.conf file can be not always straight forward. There are | |
725 | two on each cluster, one in `/etc/pve/corosync.conf` and the other in | |
726 | `/etc/corosync/corosync.conf`. Editing the one in our cluster file system will | |
727 | propagate the changes to the local one, but not vice versa. | |
728 | ||
729 | The configuration will get updated automatically as soon as the file changes. | |
730 | This means changes which can be integrated in a running corosync will take | |
731 | instantly effect. So you should always make a copy and edit that instead, to | |
732 | avoid triggering some unwanted changes by an in between safe. | |
733 | ||
734 | [source,bash] | |
4d19cb00 | 735 | ---- |
e4ec4154 | 736 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.new |
4d19cb00 | 737 | ---- |
e4ec4154 TL |
738 | |
739 | Then open the Config file with your favorite editor, `nano` and `vim.tiny` are | |
740 | preinstalled on {pve} for example. | |
741 | ||
742 | NOTE: Always increment the 'config_version' number on configuration changes, | |
743 | omitting this can lead to problems. | |
744 | ||
745 | After making the necessary changes create another copy of the current working | |
746 | configuration file. This serves as a backup if the new configuration fails to | |
747 | apply or makes problems in other ways. | |
748 | ||
749 | [source,bash] | |
4d19cb00 | 750 | ---- |
e4ec4154 | 751 | cp /etc/pve/corosync.conf /etc/pve/corosync.conf.bak |
4d19cb00 | 752 | ---- |
e4ec4154 TL |
753 | |
754 | Then move the new configuration file over the old one: | |
755 | [source,bash] | |
4d19cb00 | 756 | ---- |
e4ec4154 | 757 | mv /etc/pve/corosync.conf.new /etc/pve/corosync.conf |
4d19cb00 | 758 | ---- |
e4ec4154 TL |
759 | |
760 | You may check with the commands | |
761 | [source,bash] | |
4d19cb00 | 762 | ---- |
e4ec4154 TL |
763 | systemctl status corosync |
764 | journalctl -b -u corosync | |
4d19cb00 | 765 | ---- |
e4ec4154 TL |
766 | |
767 | If the change could applied automatically. If not you may have to restart the | |
768 | corosync service via: | |
769 | [source,bash] | |
4d19cb00 | 770 | ---- |
e4ec4154 | 771 | systemctl restart corosync |
4d19cb00 | 772 | ---- |
e4ec4154 TL |
773 | |
774 | On errors check the troubleshooting section below. | |
775 | ||
776 | Troubleshooting | |
777 | ~~~~~~~~~~~~~~~ | |
778 | ||
779 | Issue: 'quorum.expected_votes must be configured' | |
780 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
781 | ||
782 | When corosync starts to fail and you get the following message in the system log: | |
783 | ||
784 | ---- | |
785 | [...] | |
786 | corosync[1647]: [QUORUM] Quorum provider: corosync_votequorum failed to initialize. | |
787 | corosync[1647]: [SERV ] Service engine 'corosync_quorum' failed to load for reason | |
788 | 'configuration error: nodelist or quorum.expected_votes must be configured!' | |
789 | [...] | |
790 | ---- | |
791 | ||
792 | It means that the hostname you set for corosync 'ringX_addr' in the | |
793 | configuration could not be resolved. | |
794 | ||
795 | ||
796 | Write Configuration When Not Quorate | |
797 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
798 | ||
799 | If you need to change '/etc/pve/corosync.conf' on an node with no quorum, and you | |
800 | know what you do, use: | |
801 | [source,bash] | |
4d19cb00 | 802 | ---- |
e4ec4154 | 803 | pvecm expected 1 |
4d19cb00 | 804 | ---- |
e4ec4154 TL |
805 | |
806 | This sets the expected vote count to 1 and makes the cluster quorate. You can | |
807 | now fix your configuration, or revert it back to the last working backup. | |
808 | ||
809 | This is not enough if corosync cannot start anymore. Here its best to edit the | |
810 | local copy of the corosync configuration in '/etc/corosync/corosync.conf' so | |
811 | that corosync can start again. Ensure that on all nodes this configuration has | |
812 | the same content to avoid split brains. If you are not sure what went wrong | |
813 | it's best to ask the Proxmox Community to help you. | |
814 | ||
815 | ||
816 | [[corosync-conf-glossary]] | |
817 | Corosync Configuration Glossary | |
818 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
819 | ||
820 | ringX_addr:: | |
821 | This names the different ring addresses for the corosync totem rings used for | |
822 | the cluster communication. | |
823 | ||
824 | bindnetaddr:: | |
825 | Defines to which interface the ring should bind to. It may be any address of | |
826 | the subnet configured on the interface we want to use. In general its the | |
827 | recommended to just use an address a node uses on this interface. | |
828 | ||
829 | rrp_mode:: | |
830 | Specifies the mode of the redundant ring protocol and may be passive, active or | |
831 | none. Note that use of active is highly experimental and not official | |
832 | supported. Passive is the preferred mode, it may double the cluster | |
833 | communication throughput and increases availability. | |
834 | ||
806ef12d DM |
835 | |
836 | Cluster Cold Start | |
837 | ------------------ | |
838 | ||
839 | It is obvious that a cluster is not quorate when all nodes are | |
840 | offline. This is a common case after a power failure. | |
841 | ||
842 | NOTE: It is always a good idea to use an uninterruptible power supply | |
8c1189b6 | 843 | (``UPS'', also called ``battery backup'') to avoid this state, especially if |
806ef12d DM |
844 | you want HA. |
845 | ||
8c1189b6 FG |
846 | On node startup, service `pve-manager` is started and waits for |
847 | quorum. Once quorate, it starts all guests which have the `onboot` | |
612417fd DM |
848 | flag set. |
849 | ||
850 | When you turn on nodes, or when power comes back after power failure, | |
851 | it is likely that some nodes boots faster than others. Please keep in | |
852 | mind that guest startup is delayed until you reach quorum. | |
806ef12d | 853 | |
054a7e7d | 854 | |
082ea7d9 TL |
855 | Guest Migration |
856 | --------------- | |
857 | ||
054a7e7d DM |
858 | Migrating virtual guests to other nodes is a useful feature in a |
859 | cluster. There are settings to control the behavior of such | |
860 | migrations. This can be done via the configuration file | |
861 | `datacenter.cfg` or for a specific migration via API or command line | |
862 | parameters. | |
863 | ||
082ea7d9 TL |
864 | |
865 | Migration Type | |
866 | ~~~~~~~~~~~~~~ | |
867 | ||
868 | The migration type defines if the migration data should be sent over a | |
d63be10b | 869 | encrypted (`secure`) channel or an unencrypted (`insecure`) one. |
082ea7d9 | 870 | Setting the migration type to insecure means that the RAM content of a |
b1743473 DM |
871 | virtual guest gets also transfered unencrypted, which can lead to |
872 | information disclosure of critical data from inside the guest (for | |
873 | example passwords or encryption keys). | |
054a7e7d DM |
874 | |
875 | Therefore, we strongly recommend using the secure channel if you do | |
876 | not have full control over the network and can not guarantee that no | |
877 | one is eavesdropping to it. | |
082ea7d9 | 878 | |
054a7e7d DM |
879 | NOTE: Storage migration does not follow this setting. Currently, it |
880 | always sends the storage content over a secure channel. | |
881 | ||
882 | Encryption requires a lot of computing power, so this setting is often | |
883 | changed to "unsafe" to achieve better performance. The impact on | |
884 | modern systems is lower because they implement AES encryption in | |
b1743473 DM |
885 | hardware. The performance impact is particularly evident in fast |
886 | networks where you can transfer 10 Gbps or more. | |
082ea7d9 | 887 | |
082ea7d9 TL |
888 | |
889 | Migration Network | |
890 | ~~~~~~~~~~~~~~~~~ | |
891 | ||
a9baa444 TL |
892 | By default, {pve} uses the network in which cluster communication |
893 | takes place to send the migration traffic. This is not optimal because | |
894 | sensitive cluster traffic can be disrupted and this network may not | |
895 | have the best bandwidth available on the node. | |
896 | ||
897 | Setting the migration network parameter allows the use of a dedicated | |
898 | network for the entire migration traffic. In addition to the memory, | |
899 | this also affects the storage traffic for offline migrations. | |
900 | ||
901 | The migration network is set as a network in the CIDR notation. This | |
902 | has the advantage that you do not have to set individual IP addresses | |
903 | for each node. {pve} can determine the real address on the | |
904 | destination node from the network specified in the CIDR form. To | |
905 | enable this, the network must be specified so that each node has one, | |
906 | but only one IP in the respective network. | |
907 | ||
082ea7d9 TL |
908 | |
909 | Example | |
910 | ^^^^^^^ | |
911 | ||
a9baa444 TL |
912 | We assume that we have a three-node setup with three separate |
913 | networks. One for public communication with the Internet, one for | |
914 | cluster communication and a very fast one, which we want to use as a | |
915 | dedicated network for migration. | |
916 | ||
917 | A network configuration for such a setup might look as follows: | |
082ea7d9 TL |
918 | |
919 | ---- | |
920 | iface eth0 inet manual | |
921 | ||
922 | # public network | |
923 | auto vmbr0 | |
924 | iface vmbr0 inet static | |
925 | address 192.X.Y.57 | |
926 | netmask 255.255.250.0 | |
927 | gateway 192.X.Y.1 | |
928 | bridge_ports eth0 | |
929 | bridge_stp off | |
930 | bridge_fd 0 | |
931 | ||
932 | # cluster network | |
933 | auto eth1 | |
934 | iface eth1 inet static | |
935 | address 10.1.1.1 | |
936 | netmask 255.255.255.0 | |
937 | ||
938 | # fast network | |
939 | auto eth2 | |
940 | iface eth2 inet static | |
941 | address 10.1.2.1 | |
942 | netmask 255.255.255.0 | |
082ea7d9 TL |
943 | ---- |
944 | ||
a9baa444 TL |
945 | Here, we will use the network 10.1.2.0/24 as a migration network. For |
946 | a single migration, you can do this using the `migration_network` | |
947 | parameter of the command line tool: | |
948 | ||
082ea7d9 | 949 | ---- |
b1743473 | 950 | # qm migrate 106 tre --online --migration_network 10.1.2.0/24 |
082ea7d9 TL |
951 | ---- |
952 | ||
a9baa444 TL |
953 | To configure this as the default network for all migrations in the |
954 | cluster, set the `migration` property of the `/etc/pve/datacenter.cfg` | |
955 | file: | |
956 | ||
082ea7d9 | 957 | ---- |
a9baa444 | 958 | # use dedicated migration network |
b1743473 | 959 | migration: secure,network=10.1.2.0/24 |
082ea7d9 TL |
960 | ---- |
961 | ||
a9baa444 TL |
962 | NOTE: The migration type must always be set when the migration network |
963 | gets set in `/etc/pve/datacenter.cfg`. | |
964 | ||
806ef12d | 965 | |
d8742b0c DM |
966 | ifdef::manvolnum[] |
967 | include::pve-copyright.adoc[] | |
968 | endif::manvolnum[] |