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Update pvecm documentation for corosync 3

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Parts about multicast and RRP have been removed entirely. Instead, a new
section 'Corosync Redundancy' has been added explaining the concept of
links and link priorities.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
This commit is contained in:
Stefan Reiter 2019-07-09 12:25:38 +02:00 committed by Thomas Lamprecht
parent 3254bfddb3
commit a9e7c3aa23
1 changed files with 218 additions and 228 deletions
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@ -56,13 +56,8 @@ Grouping nodes into a cluster has the following advantages:
Requirements Requirements
------------ ------------
* All nodes must be in the same network as `corosync` uses IP Multicast * All nodes must be able to connect to each other via UDP ports 5404 and 5405
to communicate between nodes (also see for corosync to work.
http://www.corosync.org[Corosync Cluster Engine]). Corosync uses UDP
ports 5404 and 5405 for cluster communication.
+
NOTE: Some switches do not support IP multicast by default and must be
manually enabled first.
* Date and time have to be synchronized. * Date and time have to be synchronized.
@ -84,6 +79,11 @@ NOTE: While it's possible for {pve} 4.4 and {pve} 5.0 this is not supported as
production configuration and should only used temporarily during upgrading the production configuration and should only used temporarily during upgrading the
whole cluster from one to another major version. whole cluster from one to another major version.
NOTE: Running a cluster of {pve} 6.x with earlier versions is not possible. The
cluster protocol (corosync) between {pve} 6.x and earlier versions changed
fundamentally. The corosync 3 packages for {pve} 5.4 are only intended for the
upgrade procedure to {pve} 6.0.
Preparing Nodes Preparing Nodes
--------------- ---------------
@ -96,10 +96,13 @@ Currently the cluster creation can either be done on the console (login via
`ssh`) or the API, which we have a GUI implementation for (__Datacenter -> `ssh`) or the API, which we have a GUI implementation for (__Datacenter ->
Cluster__). Cluster__).
While it's often common use to reference all other nodenames in `/etc/hosts` While it's common to reference all nodenames and their IPs in `/etc/hosts` (or
with their IP this is not strictly necessary for a cluster, which normally uses make their names resolvable through other means), this is not necessary for a
multicast, to work. It maybe useful as you then can connect from one node to cluster to work. It may be useful however, as you can then connect from one node
the other with SSH through the easier to remember node name. to the other with SSH via the easier to remember node name (see also
xref:pvecm_corosync_addresses[Link Address Types]). Note that we always
recommend to reference nodes by their IP addresses in the cluster configuration.
[[pvecm_create_cluster]] [[pvecm_create_cluster]]
Create the Cluster Create the Cluster
@ -113,10 +116,10 @@ node names.
hp1# pvecm create CLUSTERNAME hp1# pvecm create CLUSTERNAME
---- ----
CAUTION: The cluster name is used to compute the default multicast address. NOTE: It is possible to create multiple clusters in the same physical or logical
Please use unique cluster names if you run more than one cluster inside your network. Use unique cluster names if you do so. To avoid human confusion, it is
network. To avoid human confusion, it is also recommended to choose different also recommended to choose different names even if clusters do not share the
names even if clusters do not share the cluster network. cluster network.
To check the state of your cluster use: To check the state of your cluster use:
@ -124,20 +127,6 @@ To check the state of your cluster use:
hp1# pvecm status hp1# pvecm status
---- ----
Multiple Clusters In Same Network
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It is possible to create multiple clusters in the same physical or logical
network. Each cluster must have a unique name, which is used to generate the
cluster's multicast group address. As long as no duplicate cluster names are
configured in one network segment, the different clusters won't interfere with
each other.
If multiple clusters operate in a single network it may be beneficial to setup
an IGMP querier and enable IGMP Snooping in said network. This may reduce the
load of the network significantly because multicast packets are only delivered
to endpoints of the respective member nodes.
[[pvecm_join_node_to_cluster]] [[pvecm_join_node_to_cluster]]
Adding Nodes to the Cluster Adding Nodes to the Cluster
@ -150,7 +139,7 @@ Login via `ssh` to the node you want to add.
---- ----
For `IP-ADDRESS-CLUSTER` use the IP or hostname of an existing cluster node. For `IP-ADDRESS-CLUSTER` use the IP or hostname of an existing cluster node.
An IP address is recommended (see xref:pvecm_corosync_addresses[Ring Address Types]). An IP address is recommended (see xref:pvecm_corosync_addresses[Link Address Types]).
CAUTION: A new node cannot hold any VMs, because you would get CAUTION: A new node cannot hold any VMs, because you would get
conflicts about identical VM IDs. Also, all existing configuration in conflicts about identical VM IDs. Also, all existing configuration in
@ -158,7 +147,7 @@ conflicts about identical VM IDs. Also, all existing configuration in
workaround, use `vzdump` to backup and restore to a different VMID after workaround, use `vzdump` to backup and restore to a different VMID after
adding the node to the cluster. adding the node to the cluster.
To check the state of cluster: To check the state of the cluster use:
---- ----
# pvecm status # pvecm status
@ -173,7 +162,7 @@ Date: Mon Apr 20 12:30:13 2015
Quorum provider: corosync_votequorum Quorum provider: corosync_votequorum
Nodes: 4 Nodes: 4
Node ID: 0x00000001 Node ID: 0x00000001
Ring ID: 1928 Ring ID: 1/8
Quorate: Yes Quorate: Yes
Votequorum information Votequorum information
@ -217,15 +206,15 @@ Adding Nodes With Separated Cluster Network
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When adding a node to a cluster with a separated cluster network you need to When adding a node to a cluster with a separated cluster network you need to
use the 'ringX_addr' parameters to set the nodes address on those networks: use the 'link0' parameter to set the nodes address on that network:
[source,bash] [source,bash]
---- ----
pvecm add IP-ADDRESS-CLUSTER -ring0_addr IP-ADDRESS-RING0 pvecm add IP-ADDRESS-CLUSTER -link0 LOCAL-IP-ADDRESS-LINK0
---- ----
If you want to use the Redundant Ring Protocol you will also want to pass the If you want to use the built-in xref:pvecm_redundancy[redundancy] of the
'ring1_addr' parameter. kronosnet transport layer, also use the 'link1' parameter.
Remove a Cluster Node Remove a Cluster Node
@ -283,7 +272,7 @@ Date: Mon Apr 20 12:44:28 2015
Quorum provider: corosync_votequorum Quorum provider: corosync_votequorum
Nodes: 3 Nodes: 3
Node ID: 0x00000001 Node ID: 0x00000001
Ring ID: 1992 Ring ID: 1/8
Quorate: Yes Quorate: Yes
Votequorum information Votequorum information
@ -302,8 +291,8 @@ Membership information
0x00000003 1 192.168.15.92 0x00000003 1 192.168.15.92
---- ----
If, for whatever reason, you want that this server joins the same If, for whatever reason, you want this server to join the same cluster again,
cluster again, you have to you have to
* reinstall {pve} on it from scratch * reinstall {pve} on it from scratch
@ -329,14 +318,14 @@ storage with another cluster, as storage locking doesn't work over cluster
boundary. Further, it may also lead to VMID conflicts. boundary. Further, it may also lead to VMID conflicts.
Its suggested that you create a new storage where only the node which you want Its suggested that you create a new storage where only the node which you want
to separate has access. This can be an new export on your NFS or a new Ceph to separate has access. This can be a new export on your NFS or a new Ceph
pool, to name a few examples. Its just important that the exact same storage pool, to name a few examples. Its just important that the exact same storage
does not gets accessed by multiple clusters. After setting this storage up move does not gets accessed by multiple clusters. After setting this storage up move
all data from the node and its VMs to it. Then you are ready to separate the all data from the node and its VMs to it. Then you are ready to separate the
node from the cluster. node from the cluster.
WARNING: Ensure all shared resources are cleanly separated! You will run into WARNING: Ensure all shared resources are cleanly separated! Otherwise you will
conflicts and problems else. run into conflicts and problems.
First stop the corosync and the pve-cluster services on the node: First stop the corosync and the pve-cluster services on the node:
[source,bash] [source,bash]
@ -400,6 +389,7 @@ the nodes can still connect to each other with public key authentication. This
should be fixed by removing the respective keys from the should be fixed by removing the respective keys from the
'/etc/pve/priv/authorized_keys' file. '/etc/pve/priv/authorized_keys' file.
Quorum Quorum
------ ------
@ -419,12 +409,13 @@ if it loses quorum.
NOTE: {pve} assigns a single vote to each node by default. NOTE: {pve} assigns a single vote to each node by default.
Cluster Network Cluster Network
--------------- ---------------
The cluster network is the core of a cluster. All messages sent over it have to The cluster network is the core of a cluster. All messages sent over it have to
be delivered reliable to all nodes in their respective order. In {pve} this be delivered reliably to all nodes in their respective order. In {pve} this
part is done by corosync, an implementation of a high performance low overhead part is done by corosync, an implementation of a high performance, low overhead
high availability development toolkit. It serves our decentralized high availability development toolkit. It serves our decentralized
configuration file system (`pmxcfs`). configuration file system (`pmxcfs`).
@ -432,75 +423,57 @@ configuration file system (`pmxcfs`).
Network Requirements Network Requirements
~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
This needs a reliable network with latencies under 2 milliseconds (LAN This needs a reliable network with latencies under 2 milliseconds (LAN
performance) to work properly. While corosync can also use unicast for performance) to work properly. The network should not be used heavily by other
communication between nodes its **highly recommended** to have a multicast members, ideally corosync runs on its own network. Do not use a shared network
capable network. The network should not be used heavily by other members, for corosync and storage (except as a potential low-priority fallback in a
ideally corosync runs on its own network. xref:pvecm_redundancy[redundant] configuration).
*never* share it with network where storage communicates too.
Before setting up a cluster it is good practice to check if the network is fit Before setting up a cluster, it is good practice to check if the network is fit
for that purpose. for that purpose. To make sure the nodes can connect to each other on the
cluster network, you can test the connectivity between them with the `ping`
tool.
* Ensure that all nodes are in the same subnet. This must only be true for the If the {pve} firewall is enabled, ACCEPT rules for corosync will automatically
network interfaces used for cluster communication (corosync). be generated - no manual action is required.
* Ensure all nodes can reach each other over those interfaces, using `ping` is NOTE: Corosync used Multicast before version 3.0 (introduced in {pve} 6.0).
enough for a basic test. Modern versions rely on https://kronosnet.org/[Kronosnet] for cluster
communication, which, for now, only supports regular UDP unicast.
* Ensure that multicast works in general and a high package rates. This can be CAUTION: You can still enable Multicast or legacy unicast by setting your
done with the `omping` tool. The final "%loss" number should be < 1%. transport to `udp` or `udpu` in your xref:pvecm_edit_corosync_conf[corosync.conf],
+ but keep in mind that this will disable all cryptography and redundancy support.
[source,bash] This is therefore not recommended.
----
omping -c 10000 -i 0.001 -F -q NODE1-IP NODE2-IP ...
----
* Ensure that multicast communication works over an extended period of time.
This uncovers problems where IGMP snooping is activated on the network but
no multicast querier is active. This test has a duration of around 10
minutes.
+
[source,bash]
----
omping -c 600 -i 1 -q NODE1-IP NODE2-IP ...
----
Your network is not ready for clustering if any of these test fails. Recheck
your network configuration. Especially switches are notorious for having
multicast disabled by default or IGMP snooping enabled with no IGMP querier
active.
In smaller cluster its also an option to use unicast if you really cannot get
multicast to work.
Separate Cluster Network Separate Cluster Network
~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~
When creating a cluster without any parameters the cluster network is generally When creating a cluster without any parameters the corosync cluster network is
shared with the Web UI and the VMs and its traffic. Depending on your setup generally shared with the Web UI and the VMs and their traffic. Depending on
even storage traffic may get sent over the same network. Its recommended to your setup, even storage traffic may get sent over the same network. Its
change that, as corosync is a time critical real time application. recommended to change that, as corosync is a time critical real time
application.
Setting Up A New Network Setting Up A New Network
^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^
First you have to setup a new network interface. It should be on a physical First you have to set up a new network interface. It should be on a physically
separate network. Ensure that your network fulfills the separate network. Ensure that your network fulfills the
xref:pvecm_cluster_network_requirements[cluster network requirements]. xref:pvecm_cluster_network_requirements[cluster network requirements].
Separate On Cluster Creation Separate On Cluster Creation
^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This is possible through the 'ring0_addr' and 'bindnet0_addr' parameter of This is possible via the 'linkX' parameters of the 'pvecm create'
the 'pvecm create' command used for creating a new cluster. command used for creating a new cluster.
If you have setup an additional NIC with a static address on 10.10.10.1/25 If you have set up an additional NIC with a static address on 10.10.10.1/25,
and want to send and receive all cluster communication over this interface and want to send and receive all cluster communication over this interface,
you would execute: you would execute:
[source,bash] [source,bash]
---- ----
pvecm create test --ring0_addr 10.10.10.1 --bindnet0_addr 10.10.10.0 pvecm create test --link0 10.10.10.1
---- ----
To check if everything is working properly execute: To check if everything is working properly execute:
@ -509,20 +482,20 @@ To check if everything is working properly execute:
systemctl status corosync systemctl status corosync
---- ----
Afterwards, proceed as descripted in the section to Afterwards, proceed as described above to
xref:pvecm_adding_nodes_with_separated_cluster_network[add nodes with a separated cluster network]. xref:pvecm_adding_nodes_with_separated_cluster_network[add nodes with a separated cluster network].
[[pvecm_separate_cluster_net_after_creation]] [[pvecm_separate_cluster_net_after_creation]]
Separate After Cluster Creation Separate After Cluster Creation
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
You can do this also if you have already created a cluster and want to switch You can do this if you have already created a cluster and want to switch
its communication to another network, without rebuilding the whole cluster. its communication to another network, without rebuilding the whole cluster.
This change may lead to short durations of quorum loss in the cluster, as nodes This change may lead to short durations of quorum loss in the cluster, as nodes
have to restart corosync and come up one after the other on the new network. have to restart corosync and come up one after the other on the new network.
Check how to xref:pvecm_edit_corosync_conf[edit the corosync.conf file] first. Check how to xref:pvecm_edit_corosync_conf[edit the corosync.conf file] first.
The open it and you should see a file similar to: Then, open it and you should see a file similar to:
---- ----
logging { logging {
@ -560,37 +533,41 @@ quorum {
} }
totem { totem {
cluster_name: thomas-testcluster cluster_name: testcluster
config_version: 3 config_version: 3
ip_version: ipv4 ip_version: ipv4-6
secauth: on secauth: on
version: 2 version: 2
interface { interface {
bindnetaddr: 192.168.30.50 linknumber: 0
ringnumber: 0
} }
} }
---- ----
The first you want to do is add the 'name' properties in the node entries if NOTE: `ringX_addr` actually specifies a corosync *link address*, the name "ring"
you do not see them already. Those *must* match the node name. is a remnant of older corosync versions that is kept for backwards
compatibility.
Then replace the address from the 'ring0_addr' properties with the new The first thing you want to do is add the 'name' properties in the node entries
addresses. You may use plain IP addresses or also hostnames here. If you use if you do not see them already. Those *must* match the node name.
Then replace all addresses from the 'ring0_addr' properties of all nodes with
the new addresses. You may use plain IP addresses or hostnames here. If you use
hostnames ensure that they are resolvable from all nodes. (see also hostnames ensure that they are resolvable from all nodes. (see also
xref:pvecm_corosync_addresses[Ring Address Types]) xref:pvecm_corosync_addresses[Link Address Types])
In my example I want to switch my cluster communication to the 10.10.10.1/25 In this example, we want to switch the cluster communication to the
network. So I replace all 'ring0_addr' respectively. I also set the bindnetaddr 10.10.10.1/25 network. So we replace all 'ring0_addr' respectively.
in the totem section of the config to an address of the new network. It can be
any address from the subnet configured on the new network interface.
After you increased the 'config_version' property the new configuration file NOTE: The exact same procedure can be used to change other 'ringX_addr' values
as well, although we recommend to not change multiple addresses at once, to make
it easier to recover if something goes wrong.
After we increase the 'config_version' property, the new configuration file
should look like: should look like:
---- ----
logging { logging {
debug: off debug: off
to_syslog: yes to_syslog: yes
@ -626,26 +603,28 @@ quorum {
} }
totem { totem {
cluster_name: thomas-testcluster cluster_name: testcluster
config_version: 4 config_version: 4
ip_version: ipv4 ip_version: ipv4-6
secauth: on secauth: on
version: 2 version: 2
interface { interface {
bindnetaddr: 10.10.10.1 linknumber: 0
ringnumber: 0
} }
} }
---- ----
Now after a final check whether all changed information is correct we save it Then, after a final check if all changed information is correct, we save it and
and see again the xref:pvecm_edit_corosync_conf[edit corosync.conf file] section to once again follow the xref:pvecm_edit_corosync_conf[edit corosync.conf file]
learn how to bring it in effect. section to bring it into effect.
As our change cannot be enforced live from corosync we have to do an restart. The changes will be applied live, so restarting corosync is not strictly
necessary. If you changed other settings as well, or notice corosync
complaining, you can optionally trigger a restart.
On a single node execute: On a single node execute:
[source,bash] [source,bash]
---- ----
systemctl restart corosync systemctl restart corosync
@ -665,7 +644,8 @@ They will then join the cluster membership one by one on the new network.
Corosync addresses Corosync addresses
~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
A corosync link or ring address can be specified in two ways: A corosync link address (for backwards compatibility denoted by 'ringX_addr' in
`corosync.conf`) can be specified in two ways:
* **IPv4/v6 addresses** will be used directly. They are recommended, since they * **IPv4/v6 addresses** will be used directly. They are recommended, since they
are static and usually not changed carelessly. are static and usually not changed carelessly.
@ -691,104 +671,132 @@ Nodes that joined the cluster on earlier versions likely still use their
unresolved hostname in `corosync.conf`. It might be a good idea to replace unresolved hostname in `corosync.conf`. It might be a good idea to replace
them with IPs or a seperate hostname, as mentioned above. them with IPs or a seperate hostname, as mentioned above.
[[pvecm_rrp]]
Redundant Ring Protocol
~~~~~~~~~~~~~~~~~~~~~~~
To avoid a single point of failure you should implement counter measurements.
This can be on the hardware and operating system level through network bonding.
Corosync itself offers also a possibility to add redundancy through the so [[pvecm_redundancy]]
called 'Redundant Ring Protocol'. This protocol allows running a second totem Corosync Redundancy
ring on another network, this network should be physically separated from the -------------------
other rings network to actually increase availability.
RRP On Cluster Creation Corosync supports redundant networking via its integrated kronosnet layer by
~~~~~~~~~~~~~~~~~~~~~~~ default (it is not supported on the legacy udp/udpu transports). It can be
enabled by specifying more than one link address, either via the '--linkX'
parameters of `pvecm` (while creating a cluster or adding a new node) or by
specifying more than one 'ringX_addr' in `corosync.conf`.
The 'pvecm create' command provides the additional parameters 'bindnetX_addr', NOTE: To provide useful failover, every link should be on its own
'ringX_addr' and 'rrp_mode', can be used for RRP configuration. physical network connection.
NOTE: See the xref:pvecm_corosync_conf_glossary[glossary] if you do not know what each parameter means. Links are used according to a priority setting. You can configure this priority
by setting 'knet_link_priority' in the corresponding interface section in
So if you have two networks, one on the 10.10.10.1/24 and the other on the `corosync.conf`, or, preferrably, using the 'priority' parameter when creating
10.10.20.1/24 subnet you would execute: your cluster with `pvecm`:
[source,bash]
----
pvecm create CLUSTERNAME -bindnet0_addr 10.10.10.1 -ring0_addr 10.10.10.1 \
-bindnet1_addr 10.10.20.1 -ring1_addr 10.10.20.1
----
RRP On Existing Clusters
~~~~~~~~~~~~~~~~~~~~~~~~
You will take similar steps as described in
xref:pvecm_separate_cluster_net_after_creation[separating the cluster network] to
enable RRP on an already running cluster. The single difference is, that you
will add `ring1` and use it instead of `ring0`.
First add a new `interface` subsection in the `totem` section, set its
`ringnumber` property to `1`. Set the interfaces `bindnetaddr` property to an
address of the subnet you have configured for your new ring.
Further set the `rrp_mode` to `passive`, this is the only stable mode.
Then add to each node entry in the `nodelist` section its new `ring1_addr`
property with the nodes additional ring address.
So if you have two networks, one on the 10.10.10.1/24 and the other on the
10.10.20.1/24 subnet, the final configuration file should look like:
---- ----
totem { # pvecm create CLUSTERNAME --link0 10.10.10.1,priority=20 --link1 10.20.20.1,priority=15
cluster_name: tweak ----
config_version: 9
ip_version: ipv4 This would cause 'link1' to be used first, since it has the lower priority.
rrp_mode: passive
secauth: on If no priorities are configured manually (or two links have the same priority),
version: 2 links will be used in order of their number, with the lower number having higher
interface { priority.
bindnetaddr: 10.10.10.1
ringnumber: 0 Even if all links are working, only the one with the highest priority will see
} corosync traffic. Link priorities cannot be mixed, i.e. links with different
interface { priorities will not be able to communicate with each other.
bindnetaddr: 10.10.20.1
ringnumber: 1 Since lower priority links will not see traffic unless all higher priorities
} have failed, it becomes a useful strategy to specify even networks used for
other tasks (VMs, storage, etc...) as low-priority links. If worst comes to
worst, a higher-latency or more congested connection might be better than no
connection at all.
Adding Redundant Links To An Existing Cluster
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To add a new link to a running configuration, first check how to
xref:pvecm_edit_corosync_conf[edit the corosync.conf file].
Then, add a new 'ringX_addr' to every node in the `nodelist` section. Make
sure that your 'X' is the same for every node you add it to, and that it is
unique for each node.
Lastly, add a new 'interface', as shown below, to your `totem`
section, replacing 'X' with your link number chosen above.
Assuming you added a link with number 1, the new configuration file could look
like this:
----
logging {
debug: off
to_syslog: yes
} }
nodelist { nodelist {
node {
name: pvecm1
nodeid: 1
quorum_votes: 1
ring0_addr: 10.10.10.1
ring1_addr: 10.10.20.1
}
node { node {
name: pvecm2 name: due
nodeid: 2 nodeid: 2
quorum_votes: 1 quorum_votes: 1
ring0_addr: 10.10.10.2 ring0_addr: 10.10.10.2
ring1_addr: 10.10.20.2 ring1_addr: 10.20.20.2
}
node {
name: tre
nodeid: 3
quorum_votes: 1
ring0_addr: 10.10.10.3
ring1_addr: 10.20.20.3
}
node {
name: uno
nodeid: 1
quorum_votes: 1
ring0_addr: 10.10.10.1
ring1_addr: 10.20.20.1
} }
[...] # other cluster nodes here
} }
[...] # other remaining config sections here quorum {
provider: corosync_votequorum
}
totem {
cluster_name: testcluster
config_version: 4
ip_version: ipv4-6
secauth: on
version: 2
interface {
linknumber: 0
}
interface {
linknumber: 1
}
}
---- ----
Bring it in effect like described in the The new link will be enabled as soon as you follow the last steps to
xref:pvecm_edit_corosync_conf[edit the corosync.conf file] section. xref:pvecm_edit_corosync_conf[edit the corosync.conf file]. A restart should not
be necessary. You can check that corosync loaded the new link using:
This is a change which cannot take live in effect and needs at least a restart ----
of corosync. Recommended is a restart of the whole cluster. journalctl -b -u corosync
----
It might be a good idea to test the new link by temporarily disconnecting the
old link on one node and making sure that its status remains online while
disconnected:
----
pvecm status
----
If you see a healthy cluster state, it means that your new link is being used.
If you cannot reboot the whole cluster ensure no High Availability services are
configured and the stop the corosync service on all nodes. After corosync is
stopped on all nodes start it one after the other again.
Corosync External Vote Support Corosync External Vote Support
------------------------------ ------------------------------
@ -832,10 +840,8 @@ for Debian based hosts, other Linux distributions should also have a package
available through their respective package manager. available through their respective package manager.
NOTE: In contrast to corosync itself, a QDevice connects to the cluster over NOTE: In contrast to corosync itself, a QDevice connects to the cluster over
TCP/IP and thus does not need a multicast capable network between itself and TCP/IP. The daemon may even run outside of the clusters LAN and can have longer
the cluster. In fact the daemon may run outside of the LAN and can have latencies than 2 ms.
longer latencies than 2 ms.
Supported Setups Supported Setups
~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~
@ -871,7 +877,6 @@ There are two drawbacks with this:
If you understand the drawbacks and implications you can decide yourself if If you understand the drawbacks and implications you can decide yourself if
you should use this technology in an odd numbered cluster setup. you should use this technology in an odd numbered cluster setup.
QDevice-Net Setup QDevice-Net Setup
~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
@ -923,7 +928,6 @@ Membership information
which means the QDevice is set up. which means the QDevice is set up.
Frequently Asked Questions Frequently Asked Questions
~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~
@ -961,15 +965,15 @@ pve# pvecm qdevice remove
//Still TODO //Still TODO
//^^^^^^^^^^ //^^^^^^^^^^
//There ist still stuff to add here //There is still stuff to add here
Corosync Configuration Corosync Configuration
---------------------- ----------------------
The `/etc/pve/corosync.conf` file plays a central role in {pve} cluster. It The `/etc/pve/corosync.conf` file plays a central role in a {pve} cluster. It
controls the cluster member ship and its network. controls the cluster membership and its network.
For reading more about it check the corosync.conf man page: For further information about it, check the corosync.conf man page:
[source,bash] [source,bash]
---- ----
man corosync.conf man corosync.conf
@ -983,23 +987,23 @@ Here are a few best practice tips for doing this.
Edit corosync.conf Edit corosync.conf
~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
Editing the corosync.conf file can be not always straight forward. There are Editing the corosync.conf file is not always very straightforward. There are
two on each cluster, one in `/etc/pve/corosync.conf` and the other in two on each cluster node, one in `/etc/pve/corosync.conf` and the other in
`/etc/corosync/corosync.conf`. Editing the one in our cluster file system will `/etc/corosync/corosync.conf`. Editing the one in our cluster file system will
propagate the changes to the local one, but not vice versa. propagate the changes to the local one, but not vice versa.
The configuration will get updated automatically as soon as the file changes. The configuration will get updated automatically as soon as the file changes.
This means changes which can be integrated in a running corosync will take This means changes which can be integrated in a running corosync will take
instantly effect. So you should always make a copy and edit that instead, to effect immediately. So you should always make a copy and edit that instead, to
avoid triggering some unwanted changes by an in between safe. avoid triggering some unwanted changes by an in-between safe.
[source,bash] [source,bash]
---- ----
cp /etc/pve/corosync.conf /etc/pve/corosync.conf.new cp /etc/pve/corosync.conf /etc/pve/corosync.conf.new
---- ----
Then open the Config file with your favorite editor, `nano` and `vim.tiny` are Then open the config file with your favorite editor, `nano` and `vim.tiny` are
preinstalled on {pve} for example. preinstalled on any {pve} node for example.
NOTE: Always increment the 'config_version' number on configuration changes, NOTE: Always increment the 'config_version' number on configuration changes,
omitting this can lead to problems. omitting this can lead to problems.
@ -1026,7 +1030,7 @@ systemctl status corosync
journalctl -b -u corosync journalctl -b -u corosync
---- ----
If the change could applied automatically. If not you may have to restart the If the change could be applied automatically. If not you may have to restart the
corosync service via: corosync service via:
[source,bash] [source,bash]
---- ----
@ -1054,7 +1058,6 @@ corosync[1647]: [SERV ] Service engine 'corosync_quorum' failed to load for re
It means that the hostname you set for corosync 'ringX_addr' in the It means that the hostname you set for corosync 'ringX_addr' in the
configuration could not be resolved. configuration could not be resolved.
Write Configuration When Not Quorate Write Configuration When Not Quorate
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -1080,19 +1083,8 @@ Corosync Configuration Glossary
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ringX_addr:: ringX_addr::
This names the different ring addresses for the corosync totem rings used for This names the different link addresses for the kronosnet connections between
the cluster communication. nodes.
bindnetaddr::
Defines to which interface the ring should bind to. It may be any address of
the subnet configured on the interface we want to use. In general its the
recommended to just use an address a node uses on this interface.
rrp_mode::
Specifies the mode of the redundant ring protocol and may be passive, active or
none. Note that use of active is highly experimental and not official
supported. Passive is the preferred mode, it may double the cluster
communication throughput and increases availability.
Cluster Cold Start Cluster Cold Start
@ -1127,10 +1119,10 @@ It makes a difference if a Guest is online or offline, or if it has
local resources (like a local disk). local resources (like a local disk).
For Details about Virtual Machine Migration see the For Details about Virtual Machine Migration see the
xref:qm_migration[QEMU/KVM Migration Chapter] xref:qm_migration[QEMU/KVM Migration Chapter].
For Details about Container Migration see the For Details about Container Migration see the
xref:pct_migration[Container Migration Chapter] xref:pct_migration[Container Migration Chapter].
Migration Type Migration Type
~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
@ -1155,7 +1147,6 @@ modern systems is lower because they implement AES encryption in
hardware. The performance impact is particularly evident in fast hardware. The performance impact is particularly evident in fast
networks where you can transfer 10 Gbps or more. networks where you can transfer 10 Gbps or more.
Migration Network Migration Network
~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
@ -1175,7 +1166,6 @@ destination node from the network specified in the CIDR form. To
enable this, the network must be specified so that each node has one, enable this, the network must be specified so that each node has one,
but only one IP in the respective network. but only one IP in the respective network.
Example Example
^^^^^^^ ^^^^^^^