1 <?xml version="1.0" encoding="iso-8859-1"?>
2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3 <refentry id="ctdbd.1">
6 <refentrytitle>ctdbd</refentrytitle>
7 <manvolnum>1</manvolnum>
12 <refname>ctdbd</refname>
13 <refpurpose>The CTDB cluster daemon</refpurpose>
18 <command>ctdbd</command>
22 <command>ctdbd</command>
23 <arg choice="opt">-? --help</arg>
24 <arg choice="opt">-d --debug=<INTEGER></arg>
25 <arg choice="req">--dbdir=<directory></arg>
26 <arg choice="req">--dbdir-persistent=<directory></arg>
27 <arg choice="opt">--event-script-dir=<directory></arg>
28 <arg choice="opt">-i --interactive</arg>
29 <arg choice="opt">--listen=<address></arg>
30 <arg choice="opt">--logfile=<filename></arg>
31 <arg choice="opt">--lvs</arg>
32 <arg choice="req">--nlist=<filename></arg>
33 <arg choice="opt">--no-lmaster</arg>
34 <arg choice="opt">--no-recmaster</arg>
35 <arg choice="opt">--nosetsched</arg>
36 <arg choice="opt">--public-addresses=<filename></arg>
37 <arg choice="opt">--public-interface=<interface></arg>
38 <arg choice="req">--reclock=<filename></arg>
39 <arg choice="opt">--single-public-ip=<address></arg>
40 <arg choice="opt">--socket=<filename></arg>
41 <arg choice="opt">--start-as-disabled</arg>
42 <arg choice="opt">--start-as-stopped</arg>
43 <arg choice="opt">--syslog</arg>
44 <arg choice="opt">--torture</arg>
45 <arg choice="opt">--transport=<STRING></arg>
46 <arg choice="opt">--usage</arg>
51 <refsect1><title>DESCRIPTION</title>
53 ctdbd is the main ctdb daemon.
56 ctdbd provides a clustered version of the TDB database with automatic rebuild/recovery of the databases upon nodefailures.
59 Combined with a cluster filesystem ctdbd provides a full HA environment for services such as clustered Samba and NFS as well as other services.
62 ctdbd provides monitoring of all nodes in the cluster and automatically reconfigures the cluster and recovers upon node failures.
65 ctdbd is the main component in clustered Samba that provides a high-availability load-sharing CIFS server cluster.
71 <title>OPTIONS</title>
74 <varlistentry><term>-? --help</term>
77 Print some help text to the screen.
82 <varlistentry><term>-d --debug=<DEBUGLEVEL></term>
85 This option sets the debuglevel on the ctdbd daemon which controls what will be written to the logfile. The default is 0 which will only log important events and errors. A larger number will provide additional logging.
90 <varlistentry><term>--dbdir=<directory></term>
93 This is the directory on local storage where ctdbd keeps the local
94 copy of the TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
97 This directory would usually be /var/ctdb .
102 <varlistentry><term>--dbdir-persistent=<directory></term>
105 This is the directory on local storage where ctdbd keeps the local
106 copy of the persistent TDB databases. This directory is local for each node and should not be stored on the shared cluster filesystem.
109 This directory would usually be /etc/ctdb/persistent .
114 <varlistentry><term>--event-script-dir=<directory></term>
117 This option is used to specify the directory where the CTDB event
121 This will normally be /etc/ctdb/events.d which is part of the ctdb distribution.
126 <varlistentry><term>-i --interactive</term>
129 By default ctdbd will detach itself from the shell and run in
130 the background as a daemon. This option makes ctdbd to start in interactive mode.
135 <varlistentry><term>--listen=<address></term>
138 This specifies which ip address ctdb will bind to. By default ctdbd will bind to the first address it finds in the /etc/ctdb/nodes file and which is also present on the local system in which case you do not need to provide this option.
141 This option is only required when you want to run multiple ctdbd daemons/nodes on the same physical host in which case there would be multiple entries in /etc/ctdb/nodes what would match a local interface.
146 <varlistentry><term>--logfile=<filename></term>
149 This is the file where ctdbd will write its log. This is usually /var/log/log.ctdb .
154 <varlistentry><term>--lvs</term>
157 This option is used to activate the LVS capability on a CTDB node.
158 Please see the LVS section.
163 <varlistentry><term>--nlist=<filename></term>
166 This file contains a list of the private ip addresses of every node in the cluster. There is one line/ip address for each node. This file must be the same for all nodes in the cluster.
169 This file is usually /etc/ctdb/nodes .
174 <varlistentry><term>--no-lmaster</term>
177 This argument specifies that this node can NOT become an lmaster
178 for records in the database. This means that it will never show up
179 in the vnnmap. This feature is primarily used for making a cluster
180 span across a WAN link and use CTDB as a WAN-accelerator.
183 Please see the "remote cluster nodes" section for more information.
188 <varlistentry><term>--no-recmaster</term>
191 This argument specifies that this node can NOT become a recmaster
192 for the database. This feature is primarily used for making a cluster
193 span across a WAN link and use CTDB as a WAN-accelerator.
196 Please see the "remote cluster nodes" section for more information.
201 <varlistentry><term>--nosetsched</term>
204 This is a ctdbd debugging option. this option is only used when
208 Normally ctdb will change its scheduler to run as a real-time
209 process. This is the default mode for a normal ctdbd operation
210 to gurarantee that ctdbd always gets the cpu cycles that it needs.
213 This option is used to tell ctdbd to NOT run as a real-time process
214 and instead run ctdbd as a normal userspace process.
215 This is useful for debugging and when you want to run ctdbd under
216 valgrind or gdb. (You dont want to attach valgrind or gdb to a
222 <varlistentry><term>--public_addresses=<filename></term>
225 When used with IP takeover this specifies a file containing the public ip addresses to use on the cluster. This file contains a list of ip addresses netmasks and interfaces. When ctdb is operational it will distribute these public ip addresses evenly across the available nodes.
228 This is usually the file /etc/ctdb/public_addresses
233 <varlistentry><term>--public-interface=<interface></term>
236 This option tells ctdb which interface to attach public-addresses
237 to and also where to attach the single-public-ip when used.
240 This is only required when using public ip addresses and only when
241 you dont specify the interface explicitly in /etc/ctdb/public_addresses or when you are using --single-public-ip.
244 If you omit this argument when using public addresses or single public ip, ctdb will not be able to send out Gratious ARPs correctly or be able to kill tcp connections correctly which will lead to application failures.
249 <varlistentry><term>--reclock=<filename></term>
252 This is the name of the lock file stored of the shared cluster filesystem that ctdbd uses to prevent split brains from occuring.
253 This file must be stored on shared storage.
256 It is possible to run CTDB without a reclock file, but then there
257 will be no protection against split brain if the network becomes
258 partitioned. Using CTDB without a reclock file is strongly
264 <varlistentry><term>--socket=<filename></term>
267 This specifies the name of the domain socket that ctdbd will create. This socket is used for local clients to attach to and communicate with the ctdbd daemon.
270 The default is /tmp/ctdb.socket . You only need to use this option if you plan to run multiple ctdbd daemons on the same physical host.
275 <varlistentry><term>--start-as-disabled</term>
278 This makes the ctdb daemon to be DISABLED when it starts up.
281 As it is DISABLED it will not get any of the public ip addresses
282 allocated to it, and thus this allow you to start ctdb on a node
283 without causing any ip address to failover from other nodes onto
287 When used, the administrator must keep track of when nodes start and
288 manually enable them again using the "ctdb enable" command, or else
289 the node will not host any services.
292 A node that is DISABLED will not host any services and will not be
293 reachable/used by any clients.
298 <varlistentry><term>--start-as-stopped</term>
301 This makes the ctdb daemon to be STOPPED when it starts up.
304 A node that is STOPPED does not host any public addresses. It is not part of the VNNMAP so it does act as an LMASTER. It also has all databases locked in recovery mode until restarted.
307 To restart and activate a STOPPED node, the command "ctdb continue" is used.
310 A node that is STOPPED will not host any services and will not be
311 reachable/used by any clients.
316 <varlistentry><term>--syslog</term>
319 Send all log messages to syslog instead of to the ctdb logfile.
324 <varlistentry><term>--torture</term>
327 This option is only used for development and testing of ctdbd. It adds artificial errors and failures to the common codepaths in ctdbd to verify that ctdbd can recover correctly for failures.
330 You do NOT want to use this option unless you are developing and testing new functionality in ctdbd.
335 <varlistentry><term>--transport=<STRING></term>
338 This option specifies which transport to use for ctdbd internode communications. The default is "tcp".
341 Currently only "tcp" is supported but "infiniband" might be
342 implemented in the future.
347 <varlistentry><term>--usage</term>
350 Print useage information to the screen.
359 <refsect1><title>Private vs Public addresses</title>
361 When used for ip takeover in a HA environment, each node in a ctdb
362 cluster has multiple ip addresses assigned to it. One private and one or more public.
365 <refsect2><title>Private address</title>
367 This is the physical ip address of the node which is configured in
368 linux and attached to a physical interface. This address uniquely
369 identifies a physical node in the cluster and is the ip addresses
370 that ctdbd will use to communicate with the ctdbd daemons on the
371 other nodes in the cluster.
374 The private addresses are configured in /etc/ctdb/nodes
375 (unless the --nlist option is used) and contain one line for each
376 node in the cluster. Each line contains the private ip address for one
377 node in the cluster. This file must be the same on all nodes in the
381 Since the private addresses are only available to the network when the
382 corresponding node is up and running you should not use these addresses
383 for clients to connect to services provided by the cluster. Instead
384 client applications should only attach to the public addresses since
385 these are guaranteed to always be available.
388 When using ip takeover, it is strongly recommended that the private
389 addresses are configured on a private network physically separated
390 from the rest of the network and that this private network is dedicated
393 Example /etc/ctdb/nodes for a four node cluster:
394 <screen format="linespecific">
401 <refsect2><title>Public address</title>
403 A public address on the other hand is not attached to an interface.
404 This address is managed by ctdbd itself and is attached/detached to
405 a physical node at runtime.
408 The ctdb cluster will assign/reassign these public addresses across the
409 available healthy nodes in the cluster. When one node fails, its public address
410 will be migrated to and taken over by a different node in the cluster
411 to ensure that all public addresses are always available to clients as
412 long as there are still nodes available capable of hosting this address.
415 These addresses are not physically attached to a specific node.
416 The 'ctdb ip' command can be used to view the current assignment of
417 public addresses and which physical node is currently serving it.
420 On each node this file contains a list of the public addresses that
421 this node is capable of hosting.
422 The list also contain the netmask and the
423 interface where this address should be attached for the case where you
424 may want to serve data out through multiple different interfaces.
426 Example /etc/ctdb/public_addresses for a node that can host 4 public addresses:
427 <screen format="linespecific">
435 In most cases this file would be the same on all nodes in a cluster but
436 there are exceptions when one may want to use different files
439 Example: 4 nodes partitioned into two subgroups :
440 <screen format="linespecific">
441 Node 0:/etc/ctdb/public_addresses
445 Node 1:/etc/ctdb/public_addresses
449 Node 2:/etc/ctdb/public_addresses
453 Node 3:/etc/ctdb/public_addresses
458 In this example nodes 0 and 1 host two public addresses on the
459 10.1.1.x network while nodes 2 and 3 host two public addresses for the
463 Ip address 10.1.1.1 can be hosted by either of nodes 0 or 1 and will be
464 available to clients as long as at least one of these two nodes are
466 If both nodes 0 and node 1 become unavailable 10.1.1.1 also becomes
467 unavailable. 10.1.1.1 can not be failed over to node 2 or node 3 since
468 these nodes do not have this ip address listed in their public
475 <refsect1><title>Node status</title>
477 The current status of each node in the cluster can be viewed by the
478 'ctdb status' command.
481 There are five possible states for a node.
485 OK - This node is fully functional.
489 DISCONNECTED - This node could not be connected through the network
490 and is currently not particpating in the cluster. If there is a
491 public IP address associated with this node it should have been taken
492 over by a different node. No services are running on this node.
496 DISABLED - This node has been administratively disabled. This node is
497 still functional and participates in the CTDB cluster but its IP
498 addresses have been taken over by a different node and no services are
499 currently being hosted.
503 UNHEALTHY - A service provided by this node is malfunctioning and should
504 be investigated. The CTDB daemon itself is operational and participates
505 in the cluster. Its public IP address has been taken over by a different
506 node and no services are currently being hosted. All unhealthy nodes
507 should be investigated and require an administrative action to rectify.
511 BANNED - This node failed too many recovery attempts and has been banned
512 from participating in the cluster for a period of RecoveryBanPeriod
513 seconds. Any public IP address has been taken over by other nodes. This
514 node does not provide any services. All banned nodes should be
515 investigated and require an administrative action to rectify. This node
516 does not perticipate in the CTDB cluster but can still be communicated
517 with. I.e. ctdb commands can be sent to it.
521 STOPPED - A node that is stopped does not host any public ip addresses,
522 nor is it part of the VNNMAP. A stopped node can not become LVSMASTER,
524 This node does not perticipate in the CTDB cluster but can still be
525 communicated with. I.e. ctdb commands can be sent to it.
530 <title>PUBLIC TUNABLES</title>
532 These are the public tuneables that can be used to control how ctdb behaves.
535 <refsect2><title>KeepaliveInterval</title>
536 <para>Default: 1</para>
538 How often should the nodes send keepalives to eachother.
541 <refsect2><title>KeepaliveLimit</title>
542 <para>Default: 5</para>
544 After how many keepalive intervals without any traffic should a node
545 wait until marking the peer as DISCONNECTED.
548 <refsect2><title>MonitorInterval</title>
549 <para>Default: 15</para>
551 How often should ctdb run the event scripts to check for a nodes health.
554 <refsect2><title>TickleUpdateInterval</title>
555 <para>Default: 20</para>
557 How often will ctdb record and store the "tickle" information used to
558 kickstart stalled tcp connections after a recovery.
561 <refsect2><title>EventScriptTimeout</title>
562 <para>Default: 20</para>
564 How long should ctdb let an event script run before aborting it and
565 marking the node unhealthy.
568 <refsect2><title>RecoveryBanPeriod</title>
569 <para>Default: 300</para>
571 If a node becomes banned causing repetitive recovery failures. The node will
572 eventually become banned from the cluster.
573 This controls how long the culprit node will be banned from the cluster
574 before it is allowed to try to join the cluster again.
575 Dont set to small. A node gets banned for a reason and it is usually due
576 to real problems with the node.
579 <refsect2><title>DatabaseHashSize</title>
580 <para>Default: 100000</para>
582 Size of the hash chains for the local store of the tdbs that ctdb manages.
585 <refsect2><title>RerecoveryTimeout</title>
586 <para>Default: 10</para>
588 Once a recovery has completed, no additional recoveries are permitted until this timeout has expired.
591 <refsect2><title>EnableBans</title>
592 <para>Default: 1</para>
594 When set to 0, this disables BANNING completely in the cluster and thus nodes can not get banned, even it they break. Dont set to 0.
597 <refsect2><title>DeterministicIPs</title>
598 <para>Default: 1</para>
600 When enabled, this tunable makes ctdb try to keep public IP addresses locked to specific nodes as far as possible. This makes it easier for debugging since you can know that as long as all nodes are healthy public IP X will always be hosted by node Y.
603 The cost of using deterministic IP address assignment is that it disables part of the logic where ctdb tries to reduce the number of public IP assignment changes in the cluster. This tunable may increase the number of IP failover/failbacks that are performed on the cluster by a small margin.
606 <refsect2><title>DisableWhenUnhealthy</title>
607 <para>Default: 0</para>
609 When set, As soon as a node becomes unhealthy, that node will also automatically become permanently DISABLED. Once a node is DISABLED, the only way to make it participate in the cluster again and host services is by manually enabling the node again using 'ctdb enable'.
612 This disables parts of the resilience and robustness of the cluster and should ONLY be used when the system administrator is actively monitoring the cluster, so that nodes can be enabled again.
615 <refsect2><title>NoIPFailback</title>
616 <para>Default: 0</para>
618 When set to 1, ctdb will not perform failback of IP addresses when a node becomes healthy. Ctdb WILL perform failover of public IP addresses when a node becomes UNHEALTHY, but when the node becomes HEALTHY again, ctdb will not fail the addresses back.
621 Use with caution! Normally when a node becomes available to the cluster
622 ctdb will try to reassign public IP addresses onto the new node as a way to distribute the workload evenly across the clusternode. Ctdb tries to make sure that all running nodes have approximately the same number of public addresses it hosts.
625 When you enable this tunable, CTDB will no longer attempt to rebalance the cluster by failing IP addresses back to the new nodes. An unbalanced cluster will therefore remain unbalanced until there is manual intervention from the administrator. When this parameter is set, you can manually fail public IP addresses over to the new node(s) using the 'ctdb moveip' command.
630 <refsect1><title>LVS</title>
632 LVS is a mode where CTDB presents one single IP address for the entire
633 cluster. This is an alternative to using public IP addresses and round-robin
634 DNS to loadbalance clients across the cluster.
638 This is similar to using a layer-4 loadbalancing switch but with some restrictions.
642 In this mode the cluster select a set of nodes in the cluster and loadbalance
643 all client access to the LVS address across this set of nodes. This set of nodes are all LVS capable nodes that are HEALTHY, or if no HEALTHY nodes exists
644 all LVS capable nodes regardless of health status.
645 LVS will however never loadbalance traffic to nodes that are BANNED,
646 STOPPED, DISABLED or DISCONNECTED. The "ctdb lvs" command is used to show
647 which nodes are currently load-balanced across.
651 One of the these nodes are elected as the LVSMASTER. This node receives all
652 traffic from clients coming in to the LVS address and multiplexes it
653 across the internal network to one of the nodes that LVS is using.
654 When responding to the client, that node will send the data back
655 directly to the client, bypassing the LVSMASTER node.
656 The command "ctdb lvsmaster" will show which node is the current
661 The path used for a client i/o is thus :
662 <screen format="linespecific">
663 (1) Client sends request packet to LVSMASTER
664 (2) LVSMASTER passes the request on to one node across the internal network.
665 (3) Selected node processes the request.
666 (4) Node responds back to client.
671 This means that all incoming traffic to the cluster will pass through
672 one physical node, which limits scalability. You can send more data to the
673 LVS address that one physical node can multiplex. This means that you
674 should not use LVS if your I/O pattern is write-intensive since you will be
675 limited in the available network bandwidth that node can handle.
676 LVS does work wery well for read-intensive workloads where only smallish
677 READ requests are going through the LVSMASTER bottleneck and the majority
678 of the traffic volume (the data in the read replies) goes straight from
679 the processing node back to the clients. For read-intensive i/o patterns you can acheive very high throughput rates in this mode.
683 Note: you can use LVS and public addresses at the same time.
686 <refsect2><title>Configuration</title>
688 To activate LVS on a CTDB node you must specify CTDB_PUBLIC_INTERFACE and
689 CTDB_LVS_PUBLIC_ADDRESS in /etc/sysconfig/ctdb.
693 You must also specify the "--lvs" command line argument to ctdbd to activete LVS as a capability of the node. This should be done automatically for you by the /etc/init.d/ctdb script.
698 <screen format="linespecific">
699 CTDB_PUBLIC_INTERFACE=eth0
700 CTDB_LVS_PUBLIC_IP=10.0.0.237
707 If you use LVS, you must still have a real/permanent address configured
708 for the public interface on each node. This address must be routable
709 and the cluster nodes must be configured so that all traffic back to client
710 hosts are routed through this interface. This is also required in order
711 to allow samba/winbind on the node to talk to the domain controller.
712 (we can not use the lvs IP address to initiate outgoing traffic)
715 I.e. make sure that you can "ping" both the domain controller and also
716 all of the clients from the node BEFORE you enable LVS. Also make sure
717 that when you ping these hosts that the traffic is routed out through the
723 <refsect1><title>REMOTE CLUSTER NODES</title>
725 It is possible to have a CTDB cluster that spans across a WAN link.
726 For example where you have a CTDB cluster in your datacentre but you also
727 want to have one additional CTDB node located at a remote branch site.
728 This is similar to how a WAN accelerator works but with the difference
729 that while a WAN-accelerator often acts as a Proxy or a MitM, in
730 the ctdb remote cluster node configuration the Samba instance at the remote site
731 IS the genuine server, not a proxy and not a MitM, and thus provides 100%
732 correct CIFS semantics to clients.
736 See the cluster as one single multihomed samba server where one of
737 the NICs (the remote node) is very far away.
741 NOTE: This does require that the cluster filesystem you use can cope
742 with WAN-link latencies. Not all cluster filesystems can handle
743 WAN-link latencies! Whether this will provide very good WAN-accelerator
744 performance or it will perform very poorly depends entirely
745 on how optimized your cluster filesystem is in handling high latency
746 for data and metadata operations.
750 To activate a node as being a remote cluster node you need to set
751 the following two parameters in /etc/sysconfig/ctdb for the remote node:
752 <screen format="linespecific">
753 CTDB_CAPABILITY_LMASTER=no
754 CTDB_CAPABILITY_RECMASTER=no
759 Verify with the command "ctdb getcapabilities" that that node no longer
760 has the recmaster or the lmaster capabilities.
766 <refsect1><title>NAT-GW</title>
768 Sometimes it is desireable to run services on the CTDB node which will
769 need to originate outgoing traffic to external servers. This might
770 be contacting NIS servers, LDAP servers etc. etc.
773 This can sometimes be problematic since there are situations when a
774 node does not have any public ip addresses assigned. This could
775 be due to the nobe just being started up and no addresses have been
776 assigned yet or it could be that the node is UNHEALTHY in which
777 case all public addresses have been migrated off.
780 If then the service status of CTDB depends on such services being
781 able to always being able to originate traffic to external resources
782 this becomes extra troublesome. The node might be UNHEALTHY because
783 the service can not be reached, and the service can not be reached
784 because the node is UNHEALTHY.
787 There are two ways to solve this problem. The first is by assigning a
788 static ip address for one public interface on every node which will allow
789 every node to be able to route traffic to the public network even
790 if there are no public addresses assigned to the node.
791 This is the simplest way but it uses up a lot of ip addresses since you
792 have to assign both static and also public addresses to each node.
794 <refsect2><title>NAT-GW</title>
796 A second way is to use the built in NAT-GW feature in CTDB.
797 With NAT-GW you assign one public NATGW address for each natgw group.
798 Each NATGW group is a set of nodes in the cluster that shares the same
799 NATGW address to talk to the outside world. Normally there would only be
800 one NATGW group spanning the entire cluster, but in situations where one
801 ctdb cluster spans multiple physical sites it is useful to have one
802 NATGW group for each of the two sites.
805 There can be multiple NATGW groups in one cluster but each node can only
806 be member of one NATGW group.
809 In each NATGW group, one of the nodes is designated the NAT Gateway
810 through which all traffic that is originated by nodes in this group
811 will be routed through if a public addresses are not available.
815 <refsect2><title>Configuration</title>
817 NAT-GW is configured in /etc/sysconfigctdb by setting the following
820 <screen format="linespecific">
821 # NAT-GW configuration
822 # Some services running on nthe CTDB node may need to originate traffic to
823 # remote servers before the node is assigned any IP addresses,
824 # This is problematic since before the node has public addresses the node might
825 # not be able to route traffic to the public networks.
826 # One solution is to have static public addresses assigned with routing
827 # in addition to the public address interfaces, thus guaranteeing that
828 # a node always can route traffic to the external network.
829 # This is the most simple solution but it uses up a large number of
830 # additional ip addresses.
832 # A more complex solution is NAT-GW.
833 # In this mode we only need one additional ip address for the cluster from
834 # the exsternal public network.
835 # One of the nodes in the cluster is elected to be hosting this ip address
836 # so it can reach the external services. This node is also configured
837 # to use NAT MASQUERADING for all traffic from the internal private network
838 # to the external network. This node is the NAT-GW node.
840 # All other nodes are set up with a default rote with a metric of 10 to point
841 # to the nat-gw node.
843 # The effect of this is that only when a node does not have a public address
844 # and thus no proper routes to the external world it will instead
845 # route all packets through the nat-gw node.
847 # CTDB_NATGW_NODES is the list of nodes that belong to this natgw group.
848 # You can have multiple natgw groups in one cluster but each node
849 # can only belong to one single natgw group.
851 # CTDB_NATGW_PUBLIC_IP=10.0.0.227/24
852 # CTDB_NATGW_PUBLIC_IFACE=eth0
853 # CTDB_NATGW_DEFAULT_GATEWAY=10.0.0.1
854 # CTDB_NATGW_PRIVATE_NETWORK=10.1.1.0/24
855 # CTDB_NATGW_NODES=/etc/ctdb/natgw_nodes
859 <refsect2><title>CTDB_NATGW_PUBLIC_IP</title>
861 This is an ip address in the public network that is used for all outgoing
862 traffic when the public addresses are not assigned.
863 This address will be assigned to one of the nodes in the cluster which
864 will masquerade all traffic for the other nodes.
867 Format of this parameter is IPADDRESS/NETMASK
871 <refsect2><title>CTDB_NATGW_PUBLIC_IFACE</title>
873 This is the physical interface where the CTDB_NATGW_PUBLIC_IP will be
874 assigned to. This should be an interface connected to the public network.
877 Format of this parameter is INTERFACE
881 <refsect2><title>CTDB_NATGW_DEFAULT_GATEWAY</title>
883 This is the default gateway to use on the node that is elected to host
884 the CTDB_NATGW_PUBLIC_IP. This is the default gateway on the public network.
887 Format of this parameter is IPADDRESS
891 <refsect2><title>CTDB_NATGW_PRIVATE_NETWORK</title>
893 This is the network/netmask used for the interal private network.
896 Format of this parameter is IPADDRESS/NETMASK
900 <refsect2><title>CTDB_NATGW_NODES</title>
902 This is the list of all nodes that belong to the same NATGW group
903 as this node. The default is /etc/ctdb/natgw_nodes.
907 <refsect2><title>Operation</title>
909 When the NAT-GW functionality is used, one of the nodes is elected
910 to act as a NAT router for all the other nodes in the group when
911 they need to originate traffic to the external public network.
914 The NAT-GW node is assigned the CTDB_NATGW_PUBLIC_IP to the designated
915 interface and the provided default route. The NAT-GW is configured
916 to act as a router and to masquerade all traffic it receives from the
917 internal private network and which is destined to the external network(s).
920 All other nodes in the group are configured with a default route of
921 metric 10 pointing to the designated NAT GW node.
924 This is implemented in the 11.natgw eventscript. Please see the
925 eventscript for further information.
934 <refsect1><title>ClamAV Daemon</title>
936 CTDB has support to manage the popular anti-virus daemon ClamAV.
937 This support is implemented through the
938 eventscript : /etc/ctdb/events.d/31.clamd.
941 <refsect2><title>Configuration</title>
943 Start by configuring CLAMAV normally and test that it works. Once this is
944 done, copy the configuration files over to all the nodes so that all nodes
945 share identical CLAMAV configurations.
946 Once this is done you can proceed with the intructions below to activate
947 CTDB support for CLAMAV.
951 First, to activate CLAMAV support in CTDB, edit /etc/sysconfig/ctdb and add the two lines :
953 <screen format="linespecific">
954 CTDB_MANAGES_CLAMD=yes
955 CTDB_CLAMD_SOCKET="/path/to/clamd.socket"
959 Second, activate the eventscript by making it executable:
961 <screen format="linespecific">
962 chmod +x /etc/ctdb/events.d/31.clamd
966 Third, CTDB will now be starting and stopping this service accordingly,
967 so make sure that the system is not configured to start/stop this service
969 On RedHat systems you can disable the system starting/stopping CLAMAV automatically by running :
970 <screen format="linespecific">
977 Once you have restarted CTDBD, use
978 <screen format="linespecific">
981 and verify that the 31.clamd eventscript is listed and that it was executed successfully.
990 <refsect1><title>SEE ALSO</title>
993 <ulink url="http://ctdb.samba.org/"/>
997 <refsect1><title>COPYRIGHT/LICENSE</title>
999 Copyright (C) Andrew Tridgell 2007
1000 Copyright (C) Ronnie sahlberg 2007
1002 This program is free software; you can redistribute it and/or modify
1003 it under the terms of the GNU General Public License as published by
1004 the Free Software Foundation; either version 3 of the License, or (at
1005 your option) any later version.
1007 This program is distributed in the hope that it will be useful, but
1008 WITHOUT ANY WARRANTY; without even the implied warranty of
1009 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1010 General Public License for more details.
1012 You should have received a copy of the GNU General Public License
1013 along with this program; if not, see http://www.gnu.org/licenses/.