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