Provided by: ctdb_1.11+git20111102-2_amd64 bug

NAME

       ctdb - clustered tdb database management utility

SYNOPSIS

       ctdb [ OPTIONS ] COMMAND ...

       ctdb [-n <node>] [-Y] [-t <timeout>] [-T <timelimit>] [-? --help] [--usage]
            [-d --debug=<INTEGER>] [--socket=<filename>]

DESCRIPTION

       ctdb is a utility to view and manage a ctdb cluster.

OPTIONS

       -n <pnn>
           This specifies the physical node number on which to execute the command. Default is to
           run the command on the daemon running on the local host.

           The physical node number is an integer that describes the node in the cluster. The
           first node has physical node number 0.

       -Y
           Produce output in machine readable form for easier parsing by scripts. Not all
           commands support this option.

       -t <timeout>
           How long should ctdb wait for the local ctdb daemon to respond to a command before
           timing out. Default is 3 seconds.

       -T <timelimit>
           A limit on how long the ctdb command will run for before it will be aborted. When this
           timelimit has been exceeded the ctdb command will terminate.

       -? --help
           Print some help text to the screen.

       --usage
           Print useage information to the screen.

       -d --debug=<debuglevel>
           Change the debug level for the command. Default is 0.

       --socket=<filename>
           Specify the socketname to use when connecting to the local ctdb daemon. The default is
           /tmp/ctdb.socket .

           You only need to specify this parameter if you run multiple ctdb daemons on the same
           physical host and thus can not use the default name for the domain socket.

ADMINISTRATIVE COMMANDS

       These are commands used to monitor and administrate a CTDB cluster.

   pnn
       This command displays the pnn of the current node.

   status
       This command shows the current status of the ctdb node.

       node status
           Node status reflects the current status of the node. There are five possible states:

           OK - This node is fully functional.

           DISCONNECTED - This node could not be connected through the network and is currently
           not participating in the cluster. If there is a public IP address associated with this
           node it should have been taken over by a different node. No services are running on
           this node.

           DISABLED - This node has been administratively disabled. This node is still functional
           and participates in the CTDB cluster but its IP addresses have been taken over by a
           different node and no services are currently being hosted.

           UNHEALTHY - A service provided by this node is malfunctioning and should be
           investigated. The CTDB daemon itself is operational and participates in the cluster.
           Its public IP address has been taken over by a different node and no services are
           currnetly being hosted. All unhealthy nodes should be investigated and require an
           administrative action to rectify.

           BANNED - This node failed too many recovery attempts and has been banned from
           participating in the cluster for a period of RecoveryBanPeriod seconds. Any public IP
           address has been taken over by other nodes. This node does not provide any services.
           All banned nodes should be investigated and require an administrative action to
           rectify. This node does not perticipate in the CTDB cluster but can still be
           communicated with. I.e. ctdb commands can be sent to it.

           STOPPED - A node that is stopped does not host any public ip addresses, nor is it part
           of the VNNMAP. A stopped node can not become LVSMASTER, RECMASTER or NATGW. This node
           does not perticipate in the CTDB cluster but can still be communicated with. I.e. ctdb
           commands can be sent to it.

           PARTIALLYONLINE - A node that is partially online participates in a cluster like a
           node that is ok. Some interfaces to serve public ip addresses are down, but at least
           one interface is up. See also "ctdb ifaces".

       generation
           The generation id is a number that indicates the current generation of a cluster
           instance. Each time a cluster goes through a reconfiguration or a recovery its
           generation id will be changed.

           This number does not have any particular meaning other than to keep track of when a
           cluster has gone through a recovery. It is a random number that represents the current
           instance of a ctdb cluster and its databases. CTDBD uses this number internally to be
           able to tell when commands to operate on the cluster and the databases was issued in a
           different generation of the cluster, to ensure that commands that operate on the
           databases will not survive across a cluster database recovery. After a recovery, all
           old outstanding commands will automatically become invalid.

           Sometimes this number will be shown as "INVALID". This only means that the ctdbd
           daemon has started but it has not yet merged with the cluster through a recovery. All
           nodes start with generation "INVALID" and are not assigned a real generation id until
           they have successfully been merged with a cluster through a recovery.

       VNNMAP
           The list of Virtual Node Numbers. This is a list of all nodes that actively
           participates in the cluster and that share the workload of hosting the Clustered TDB
           database records. Only nodes that are participating in the vnnmap can become lmaster
           or dmaster for a database record.

       Recovery mode
           This is the current recovery mode of the cluster. There are two possible modes:

           NORMAL - The cluster is fully operational.

           RECOVERY - The cluster databases have all been frozen, pausing all services while the
           cluster awaits a recovery process to complete. A recovery process should finish within
           seconds. If a cluster is stuck in the RECOVERY state this would indicate a cluster
           malfunction which needs to be investigated.

           Once the recovery master detects an inconsistency, for example a node becomes
           disconnected/connected, the recovery daemon will trigger a cluster recovery process,
           where all databases are remerged across the cluster. When this process starts, the
           recovery master will first "freeze" all databases to prevent applications such as
           samba from accessing the databases and it will also mark the recovery mode as
           RECOVERY.

           When CTDBD starts up, it will start in RECOVERY mode. Once the node has been merged
           into a cluster and all databases have been recovered, the node mode will change into
           NORMAL mode and the databases will be "thawed", allowing samba to access the databases
           again.

       Recovery master
           This is the cluster node that is currently designated as the recovery master. This
           node is responsible of monitoring the consistency of the cluster and to perform the
           actual recovery process when reqired.

           Only one node at a time can be the designated recovery master. Which node is
           designated the recovery master is decided by an election process in the recovery
           daemons running on each node.

       Example: ctdb status

       Example output:

           Number of nodes:4
           pnn:0 11.1.2.200       OK (THIS NODE)
           pnn:1 11.1.2.201       OK
           pnn:2 11.1.2.202       OK
           pnn:3 11.1.2.203       OK
           Generation:1362079228
           Size:4
           hash:0 lmaster:0
           hash:1 lmaster:1
           hash:2 lmaster:2
           hash:3 lmaster:3
           Recovery mode:NORMAL (0)
           Recovery master:0

   recmaster
       This command shows the pnn of the node which is currently the recmaster.

   uptime
       This command shows the uptime for the ctdb daemon. When the last recovery or ip-failover
       completed and how long it took. If the "duration" is shown as a negative number, this
       indicates that there is a recovery/failover in progress and it started that many seconds
       ago.

       Example: ctdb uptime

       Example output:

           Current time of node          :                Thu Oct 29 10:38:54 2009
           Ctdbd start time              : (000 16:54:28) Wed Oct 28 17:44:26 2009
           Time of last recovery/failover: (000 16:53:31) Wed Oct 28 17:45:23 2009
           Duration of last recovery/failover: 2.248552 seconds

   listnodes
       This command shows lists the ip addresses of all the nodes in the cluster.

       Example: ctdb listnodes

       Example output:

           10.0.0.71
           10.0.0.72
           10.0.0.73
           10.0.0.74

   ping
       This command will "ping" all CTDB daemons in the cluster to verify that they are
       processing commands correctly.

       Example: ctdb ping

       Example output:

           response from 0 time=0.000054 sec  (3 clients)
           response from 1 time=0.000144 sec  (2 clients)
           response from 2 time=0.000105 sec  (2 clients)
           response from 3 time=0.000114 sec  (2 clients)

   ifaces
       This command will display the list of network interfaces, which could host public
       addresses, along with their status.

       Example: ctdb ifaces

       Example output:

           Interfaces on node 0
           name:eth5 link:up references:2
           name:eth4 link:down references:0
           name:eth3 link:up references:1
           name:eth2 link:up references:1

       Example: ctdb ifaces -Y

       Example output:

           :Name:LinkStatus:References:
           :eth5:1:2
           :eth4:0:0
           :eth3:1:1
           :eth2:1:1

   setifacelink <iface> <status>
       This command will set the status of a network interface. The status needs to be "up" or
       "down". This is typically used in the 10.interfaces script in the "monitor" event.

       Example: ctdb setifacelink eth0 up

   ip
       This command will display the list of public addresses that are provided by the cluster
       and which physical node is currently serving this ip. By default this command will ONLY
       show those public addresses that are known to the node itself. To see the full list of all
       public ips across the cluster you must use "ctdb ip -n all".

       Example: ctdb ip

       Example output:

           Public IPs on node 0
           172.31.91.82 node[1] active[] available[eth2,eth3] configured[eth2,eth3]
           172.31.91.83 node[0] active[eth3] available[eth2,eth3] configured[eth2,eth3]
           172.31.91.84 node[1] active[] available[eth2,eth3] configured[eth2,eth3]
           172.31.91.85 node[0] active[eth2] available[eth2,eth3] configured[eth2,eth3]
           172.31.92.82 node[1] active[] available[eth5] configured[eth4,eth5]
           172.31.92.83 node[0] active[eth5] available[eth5] configured[eth4,eth5]
           172.31.92.84 node[1] active[] available[eth5] configured[eth4,eth5]
           172.31.92.85 node[0] active[eth5] available[eth5] configured[eth4,eth5]

       Example: ctdb ip -Y

       Example output:

           :Public IP:Node:ActiveInterface:AvailableInterfaces:ConfiguredInterfaces:
           :172.31.91.82:1::eth2,eth3:eth2,eth3:
           :172.31.91.83:0:eth3:eth2,eth3:eth2,eth3:
           :172.31.91.84:1::eth2,eth3:eth2,eth3:
           :172.31.91.85:0:eth2:eth2,eth3:eth2,eth3:
           :172.31.92.82:1::eth5:eth4,eth5:
           :172.31.92.83:0:eth5:eth5:eth4,eth5:
           :172.31.92.84:1::eth5:eth4,eth5:
           :172.31.92.85:0:eth5:eth5:eth4,eth5:

   ipinfo <ip>
       This command will display details about the specified public addresses.

       Example: ctdb ipinfo 172.31.92.85

       Example output:

           Public IP[172.31.92.85] info on node 0
           IP:172.31.92.85
           CurrentNode:0
           NumInterfaces:2
           Interface[1]: Name:eth4 Link:down References:0
           Interface[2]: Name:eth5 Link:up References:2 (active)

   scriptstatus
       This command displays which scripts where run in the previous monitoring cycle and the
       result of each script. If a script failed with an error, causing the node to become
       unhealthy, the output from that script is also shown.

       Example: ctdb scriptstatus

       Example output:

           7 scripts were executed last monitoring cycle
           00.ctdb              Status:OK    Duration:0.056 Tue Mar 24 18:56:57 2009
           10.interface         Status:OK    Duration:0.077 Tue Mar 24 18:56:57 2009
           11.natgw             Status:OK    Duration:0.039 Tue Mar 24 18:56:57 2009
           20.multipathd        Status:OK    Duration:0.038 Tue Mar 24 18:56:57 2009
           31.clamd             Status:DISABLED
           40.vsftpd            Status:OK    Duration:0.045 Tue Mar 24 18:56:57 2009
           41.httpd             Status:OK    Duration:0.039 Tue Mar 24 18:56:57 2009
           50.samba             Status:ERROR    Duration:0.082 Tue Mar 24 18:56:57 2009
              OUTPUT:ERROR: Samba tcp port 445 is not responding

   disablescript <script>
       This command is used to disable an eventscript.

       This will take effect the next time the eventscripts are being executed so it can take a
       short while until this is reflected in 'scriptstatus'.

   enablescript <script>
       This command is used to enable an eventscript.

       This will take effect the next time the eventscripts are being executed so it can take a
       short while until this is reflected in 'scriptstatus'.

   getvar <name>
       Get the runtime value of a tuneable variable.

       Example: ctdb getvar MaxRedirectCount

       Example output:

           MaxRedirectCount    = 3

   setvar <name> <value>
       Set the runtime value of a tuneable variable.

       Example: ctdb setvar MaxRedirectCount 5

   listvars
       List all tuneable variables.

       Example: ctdb listvars

       Example output:

           MaxRedirectCount    = 3
           SeqnumInterval      = 1000
           ControlTimeout      = 60
           TraverseTimeout     = 20
           KeepaliveInterval   = 5
           KeepaliveLimit      = 5
           RecoverTimeout      = 20
           RecoverInterval     = 1
           ElectionTimeout     = 3
           TakeoverTimeout     = 9
           MonitorInterval     = 15
           TickleUpdateInterval = 20
           EventScriptTimeout  = 30
           EventScriptTimeoutCount = 1
           EventScriptUnhealthyOnTimeout = 0
           RecoveryGracePeriod = 120
           RecoveryBanPeriod   = 300
           DatabaseHashSize    = 100001
           DatabaseMaxDead     = 5
           RerecoveryTimeout   = 10
           EnableBans          = 1
           DeterministicIPs    = 1
           ReclockPingPeriod   = 60
           NoIPFailback        = 0
           DisableIPFailover   = 0
           VerboseMemoryNames  = 0
           RecdPingTimeout     = 60
           RecdFailCount       = 10
           LogLatencyMs        = 0
           RecLockLatencyMs    = 1000
           RecoveryDropAllIPs  = 120
           VerifyRecoveryLock  = 1
           VacuumDefaultInterval = 10
           VacuumMaxRunTime    = 30
           RepackLimit         = 10000
           VacuumLimit         = 5000
           VacuumMinInterval   = 10
           VacuumMaxInterval   = 10
           VacuumFastPathCount = 60
           MaxQueueDropMsg     = 1000000
           UseStatusEvents     = 0
           AllowUnhealthyDBRead = 0
           StatHistoryInterval = 1
           DeferredAttachTO    = 120

   lvsmaster
       This command shows which node is currently the LVSMASTER. The LVSMASTER is the node in the
       cluster which drives the LVS system and which receives all incoming traffic from clients.

       LVS is the mode where the entire CTDB/Samba cluster uses a single ip address for the
       entire cluster. In this mode all clients connect to one specific node which will then
       multiplex/loadbalance the clients evenly onto the other nodes in the cluster. This is an
       alternative to using public ip addresses. See the manpage for ctdbd for more information
       about LVS.

   lvs
       This command shows which nodes in the cluster are currently active in the LVS
       configuration. I.e. which nodes we are currently loadbalancing the single ip address
       across.

       LVS will by default only loadbalance across those nodes that are both LVS capable and also
       HEALTHY. Except if all nodes are UNHEALTHY in which case LVS will loadbalance across all
       UNHEALTHY nodes as well. LVS will never use nodes that are DISCONNECTED, STOPPED, BANNED
       or DISABLED.

       Example output:

           2:10.0.0.13
           3:10.0.0.14

   getcapabilities
       This command shows the capabilities of the current node. Please see manpage for ctdbd for
       a full list of all capabilities and more detailed description.

       RECMASTER and LMASTER capabilities are primarily used when CTDBD is used to create a
       cluster spanning across WAN links. In which case ctdbd acts as a WAN accelerator.

       LVS capabile means that the node is participating in LVS, a mode where the entire CTDB
       cluster uses one single ip address for the entire cluster instead of using public ip
       address failover. This is an alternative to using a loadbalancing layer-4 switch.

       Example output:

           RECMASTER: YES
           LMASTER: YES
           LVS: NO

   statistics
       Collect statistics from the CTDB daemon about how many calls it has served.

       Example: ctdb statistics

       Example output:

           CTDB version 1
            num_clients                        3
            frozen                             0
            recovering                         0
            client_packets_sent           360489
            client_packets_recv           360466
            node_packets_sent             480931
            node_packets_recv             240120
            keepalive_packets_sent             4
            keepalive_packets_recv             3
            node
                req_call                       2
                reply_call                     2
                req_dmaster                    0
                reply_dmaster                  0
                reply_error                    0
                req_message                   42
                req_control               120408
                reply_control             360439
            client
                req_call                       2
                req_message                   24
                req_control               360440
            timeouts
                call                           0
                control                        0
                traverse                       0
            total_calls                        2
            pending_calls                      0
            lockwait_calls                     0
            pending_lockwait_calls             0
            memory_used                     5040
            max_hop_count                      0
            max_call_latency                   4.948321 sec
            max_lockwait_latency               0.000000 sec

   statisticsreset
       This command is used to clear all statistics counters in a node.

       Example: ctdb statisticsreset

   getreclock
       This command is used to show the filename of the reclock file that is used.

       Example output:

           Reclock file:/gpfs/.ctdb/shared

   setreclock [filename]
       This command is used to modify, or clear, the file that is used as the reclock file at
       runtime. When this command is used, the reclock file checks are disabled. To re-enable the
       checks the administrator needs to activate the "VerifyRecoveryLock" tunable using "ctdb
       setvar".

       If run with no parameter this will remove the reclock file completely. If run with a
       parameter the parameter specifies the new filename to use for the recovery lock.

       This command only affects the runtime settings of a ctdb node and will be lost when ctdb
       is restarted. For persistent changes to the reclock file setting you must edit
       /etc/sysconfig/ctdb.

   getdebug
       Get the current debug level for the node. the debug level controls what information is
       written to the log file.

       The debug levels are mapped to the corresponding syslog levels. When a debug level is set,
       only those messages at that level and higher levels will be printed.

       The list of debug levels from highest to lowest are :

       EMERG ALERT CRIT ERR WARNING NOTICE INFO DEBUG

   setdebug <debuglevel>
       Set the debug level of a node. This controls what information will be logged.

       The debuglevel is one of EMERG ALERT CRIT ERR WARNING NOTICE INFO DEBUG

   getpid
       This command will return the process id of the ctdb daemon.

   disable
       This command is used to administratively disable a node in the cluster. A disabled node
       will still participate in the cluster and host clustered TDB records but its public ip
       address has been taken over by a different node and it no longer hosts any services.

   enable
       Re-enable a node that has been administratively disabled.

   stop
       This command is used to administratively STOP a node in the cluster. A STOPPED node is
       connected to the cluster but will not host any public ip addresse, nor does it participate
       in the VNNMAP. The difference between a DISABLED node and a STOPPED node is that a STOPPED
       node does not host any parts of the database which means that a recovery is required to
       stop/continue nodes.

   continue
       Re-start a node that has been administratively stopped.

   addip <public_ip/mask> <iface>
       This command is used to add a new public ip to a node during runtime. This allows public
       addresses to be added to a cluster without having to restart the ctdb daemons.

       Note that this only updates the runtime instance of ctdb. Any changes will be lost next
       time ctdb is restarted and the public addresses file is re-read. If you want this change
       to be permanent you must also update the public addresses file manually.

   delip <public_ip>
       This command is used to remove a public ip from a node during runtime. If this public ip
       is currently hosted by the node it being removed from, the ip will first be failed over to
       another node, if possible, before it is removed.

       Note that this only updates the runtime instance of ctdb. Any changes will be lost next
       time ctdb is restarted and the public addresses file is re-read. If you want this change
       to be permanent you must also update the public addresses file manually.

   moveip <public_ip> <node>
       This command can be used to manually fail a public ip address to a specific node.

       In order to manually override the "automatic" distribution of public ip addresses that
       ctdb normally provides, this command only works when you have changed the tunables for the
       daemon to:

       DeterministicIPs = 0

       NoIPFailback = 1

   shutdown
       This command will shutdown a specific CTDB daemon.

   recover
       This command will trigger the recovery daemon to do a cluster recovery.

   ipreallocate
       This command will force the recovery master to perform a full ip reallocation process and
       redistribute all ip addresses. This is useful to "reset" the allocations back to its
       default state if they have been changed using the "moveip" command. While a "recover" will
       also perform this reallocation, a recovery is much more hevyweight since it will also
       rebuild all the databases.

   setlmasterrole <on|off>
       This command is used ot enable/disable the LMASTER capability for a node at runtime. This
       capability determines whether or not a node can be used as an LMASTER for records in the
       database. A node that does not have the LMASTER capability will not show up in the vnnmap.

       Nodes will by default have this capability, but it can be stripped off nodes by the
       setting in the sysconfig file or by using this command.

       Once this setting has been enabled/disabled, you need to perform a recovery for it to take
       effect.

       See also "ctdb getcapabilities"

   setrecmasterrole <on|off>
       This command is used ot enable/disable the RECMASTER capability for a node at runtime.
       This capability determines whether or not a node can be used as an RECMASTER for the
       cluster. A node that does not have the RECMASTER capability can not win a recmaster
       election. A node that already is the recmaster for the cluster when the capability is
       stripped off the node will remain the recmaster until the next cluster election.

       Nodes will by default have this capability, but it can be stripped off nodes by the
       setting in the sysconfig file or by using this command.

       See also "ctdb getcapabilities"

   killtcp <srcip:port> <dstip:port>
       This command will kill the specified TCP connection by issuing a TCP RST to the srcip:port
       endpoint. This is a command used by the ctdb eventscripts.

   gratiousarp <ip> <interface>
       This command will send out a gratious arp for the specified interface through the
       specified interface. This command is mainly used by the ctdb eventscripts.

   reloadnodes
       This command is used when adding new nodes, or removing existing nodes from an existing
       cluster.

       Procedure to add a node:

       1, To expand an existing cluster, first ensure with 'ctdb status' that all nodes are up
       and running and that they are all healthy. Do not try to expand a cluster unless it is
       completely healthy!

       2, On all nodes, edit /etc/ctdb/nodes and add the new node as the last entry to the file.
       The new node MUST be added to the end of this file!

       3, Verify that all the nodes have identical /etc/ctdb/nodes files after you edited them
       and added the new node!

       4, Run 'ctdb reloadnodes' to force all nodes to reload the nodesfile.

       5, Use 'ctdb status' on all nodes and verify that they now show the additional node.

       6, Install and configure the new node and bring it online.

       Procedure to remove a node:

       1, To remove a node from an existing cluster, first ensure with 'ctdb status' that all
       nodes, except the node to be deleted, are up and running and that they are all healthy. Do
       not try to remove a node from a cluster unless the cluster is completely healthy!

       2, Shutdown and poweroff the node to be removed.

       3, On all other nodes, edit the /etc/ctdb/nodes file and comment out the node to be
       removed. Do not delete the line for that node, just comment it out by adding a '#' at the
       beginning of the line.

       4, Run 'ctdb reloadnodes' to force all nodes to reload the nodesfile.

       5, Use 'ctdb status' on all nodes and verify that the deleted node no longer shows up in
       the list..

   tickle <srcip:port> <dstip:port>
       This command will will send a TCP tickle to the source host for the specified TCP
       connection. A TCP tickle is a TCP ACK packet with an invalid sequence and acknowledge
       number and will when received by the source host result in it sending an immediate correct
       ACK back to the other end.

       TCP tickles are useful to "tickle" clients after a IP failover has occured since this will
       make the client immediately recognize the TCP connection has been disrupted and that the
       client will need to reestablish. This greatly speeds up the time it takes for a client to
       detect and reestablish after an IP failover in the ctdb cluster.

   gettickles <ip>
       This command is used to show which TCP connections are registered with CTDB to be
       "tickled" if there is a failover.

   repack [max_freelist]
       Over time, when records are created and deleted in a TDB, the TDB list of free space will
       become fragmented. This can lead to a slowdown in accessing TDB records. This command is
       used to defragment a TDB database and pruning the freelist.

       If [max_freelist] is specified, then a database will only be repacked if it has more than
       this number of entries in the freelist.

       During repacking of the database, the entire TDB database will be locked to prevent
       writes. If samba tries to write to a record in the database during a repack operation,
       samba will block until the repacking has completed.

       This command can be disruptive and can cause samba to block for the duration of the repack
       operation. In general, a repack operation will take less than one second to complete.

       A repack operation will only defragment the local TDB copy of the CTDB database. You need
       to run this command on all of the nodes to repack a CTDB database completely.

       Example: ctdb repack 1000

       By default, this operation is issued from the 00.ctdb event script every 5 minutes.

   vacuum [max_records]
       Over time CTDB databases will fill up with empty deleted records which will lead to a
       progressive slow down of CTDB database access. This command is used to prune all databases
       and delete all empty records from the cluster.

       By default, vacuum will delete all empty records from all databases. If [max_records] is
       specified, the command will only delete the first [max_records] empty records for each
       database.

       Vacuum only deletes records where the local node is the lmaster. To delete all records
       from the entire cluster you need to run a vacuum from each node. This command is not
       disruptive. Samba is unaffected and will still be able to read/write records normally
       while the database is being vacuumed.

       Example: ctdb vacuum

       By default, this operation is issued from the 00.ctdb event script every 5 minutes.

   backupdb <dbname> <file>
       This command can be used to copy the entire content of a database out to a file. This file
       can later be read back into ctdb using the restoredb command. This is mainly useful for
       backing up persistent databases such as secrets.tdb and similar.

   restoredb <file> [<dbname>]
       This command restores a persistent database that was previously backed up using backupdb.
       By default the data will be restored back into the same database as it was created from.
       By specifying dbname you can restore the data into a different database.

   wipedb <dbname>
       This command can be used to remove all content of a database.

   getlog <level>
       In addition to the normal loggign to a log file, CTDBD also keeps a in-memory ringbuffer
       containing the most recent log entries for all log levels (except DEBUG).

       This is useful since it allows for keeping continuous logs to a file at a reasonable
       non-verbose level, but shortly after an incident has occured, a much more detailed log can
       be pulled from memory. This can allow you to avoid having to reproduce an issue due to the
       on-disk logs being of insufficient detail.

       This command extracts all messages of level or lower log level from memory and prints it
       to the screen.

   clearlog
       This command clears the in-memory logging ringbuffer.

DEBUGGING COMMANDS

       These commands are primarily used for CTDB development and testing and should not be used
       for normal administration.

   process-exists <pid>
       This command checks if a specific process exists on the CTDB host. This is mainly used by
       Samba to check if remote instances of samba are still running or not.

   getdbmap
       This command lists all clustered TDB databases that the CTDB daemon has attached to. Some
       databases are flagged as PERSISTENT, this means that the database stores data persistently
       and the data will remain across reboots. One example of such a database is secrets.tdb
       where information about how the cluster was joined to the domain is stored.

       If a PERSISTENT database is not in a healthy state the database is flagged as UNHEALTHY.
       If there's at least one completely healthy node running in the cluster, it's possible that
       the content is restored by a recovery run automaticly. Otherwise an administrator needs to
       analyze the problem.

       See also "ctdb getdbstatus", "ctdb backupdb", "ctdb restoredb", "ctdb dumpbackup", "ctdb
       wipedb", "ctdb setvar AllowUnhealthyDBRead 1" and (if samba or tdb-utils are installed)
       "tdbtool check".

       Most databases are not persistent and only store the state information that the currently
       running samba daemons need. These databases are always wiped when ctdb/samba starts and
       when a node is rebooted.

       Example: ctdb getdbmap

       Example output:

           Number of databases:10
           dbid:0x435d3410 name:notify.tdb path:/var/ctdb/notify.tdb.0
           dbid:0x42fe72c5 name:locking.tdb path:/var/ctdb/locking.tdb.0
           dbid:0x1421fb78 name:brlock.tdb path:/var/ctdb/brlock.tdb.0
           dbid:0x17055d90 name:connections.tdb path:/var/ctdb/connections.tdb.0
           dbid:0xc0bdde6a name:sessionid.tdb path:/var/ctdb/sessionid.tdb.0
           dbid:0x122224da name:test.tdb path:/var/ctdb/test.tdb.0
           dbid:0x2672a57f name:idmap2.tdb path:/var/ctdb/persistent/idmap2.tdb.0 PERSISTENT
           dbid:0xb775fff6 name:secrets.tdb path:/var/ctdb/persistent/secrets.tdb.0 PERSISTENT
           dbid:0xe98e08b6 name:group_mapping.tdb path:/var/ctdb/persistent/group_mapping.tdb.0 PERSISTENT
           dbid:0x7bbbd26c name:passdb.tdb path:/var/ctdb/persistent/passdb.tdb.0 PERSISTENT

       Example output for an unhealthy database:

           Number of databases:1
           dbid:0xb775fff6 name:secrets.tdb path:/var/ctdb/persistent/secrets.tdb.0 PERSISTENT UNHEALTHY

       Example output for a healthy database as machinereadable output -Y:

           :ID:Name:Path:Persistent:Unhealthy:
           :0x7bbbd26c:passdb.tdb:/var/ctdb/persistent/passdb.tdb.0:1:0:

   getdbstatus <dbname>
       This command displays more details about a database.

       Example: ctdb getdbstatus test.tdb.0

       Example output:

           dbid: 0x122224da
           name: test.tdb
           path: /var/ctdb/test.tdb.0
           PERSISTENT: no
           HEALTH: OK

       Example: ctdb getdbstatus registry.tdb (with a corrupted TDB)

       Example output:

           dbid: 0xf2a58948
           name: registry.tdb
           path: /var/ctdb/persistent/registry.tdb.0
           PERSISTENT: yes
           HEALTH: NO-HEALTHY-NODES - ERROR - Backup of corrupted TDB in '/var/ctdb/persistent/registry.tdb.0.corrupted.20091208091949.0Z'

   catdb <dbname>
       This command will dump a clustered TDB database to the screen. This is a debugging
       command.

   cattdb <dbname>
       This command will dump the content of the local TDB database to the screen. This is a
       debugging command.

   dumpdbbackup <backup-file>
       This command will dump the content of database backup to the screen (similar to ctdb
       catdb). This is a debugging command.

   getmonmode
       This command returns the monutoring mode of a node. The monitoring mode is either ACTIVE
       or DISABLED. Normally a node will continuously monitor that all other nodes that are
       expected are in fact connected and that they respond to commands.

       ACTIVE - This is the normal mode. The node is actively monitoring all other nodes, both
       that the transport is connected and also that the node responds to commands. If a node
       becomes unavailable, it will be marked as DISCONNECTED and a recovery is initiated to
       restore the cluster.

       DISABLED - This node is not monitoring that other nodes are available. In this mode a node
       failure will not be detected and no recovery will be performed. This mode is useful when
       for debugging purposes one wants to attach GDB to a ctdb process but wants to prevent the
       rest of the cluster from marking this node as DISCONNECTED and do a recovery.

   setmonmode <0|1>
       This command can be used to explicitly disable/enable monitoring mode on a node. The main
       purpose is if one wants to attach GDB to a running ctdb daemon but wants to prevent the
       other nodes from marking it as DISCONNECTED and issuing a recovery. To do this, set
       monitoring mode to 0 on all nodes before attaching with GDB. Remember to set monitoring
       mode back to 1 afterwards.

   attach <dbname> [persistent]
       This is a debugging command. This command will make the CTDB daemon create a new CTDB
       database and attach to it.

   dumpmemory
       This is a debugging command. This command will make the ctdb daemon to write a fill memory
       allocation map to standard output.

   rddumpmemory
       This is a debugging command. This command will dump the talloc memory allocation tree for
       the recovery daemon to standard output.

   thaw
       Thaw a previously frozen node.

   eventscript <arguments>
       This is a debugging command. This command can be used to manually invoke and run the
       eventscritps with arbitrary arguments.

   ban <bantime|0>
       Administratively ban a node for bantime seconds. A bantime of 0 means that the node should
       be permanently banned.

       A banned node does not participate in the cluster and does not host any records for the
       clustered TDB. Its ip address has been taken over by another node and no services are
       hosted.

       Nodes are automatically banned if they are the cause of too many cluster recoveries.

       This is primarily a testing command. Note that the recovery daemon controls the overall
       ban state and it may automatically unban nodes at will. Meaning that a node that has been
       banned by the administrator can and ofter are unbanned before the admin specifid timeout
       triggers. If wanting to "drop" a node out from the cluster for mainentance or other
       reasons, use the "stop" / "continue" commands instad of "ban" / "unban".

   unban
       This command is used to unban a node that has either been administratively banned using
       the ban command or has been automatically banned by the recovery daemon.

SEE ALSO

       ctdbd(1), onnode(1) http://ctdb.samba.org/

COPYRIGHT/LICENSE

           Copyright (C) Andrew Tridgell 2007
           Copyright (C) Ronnie sahlberg 2007

           This program is free software; you can redistribute it and/or modify
           it under the terms of the GNU General Public License as published by
           the Free Software Foundation; either version 3 of the License, or (at
           your option) any later version.

           This program is distributed in the hope that it will be useful, but
           WITHOUT ANY WARRANTY; without even the implied warranty of
           MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
           General Public License for more details.

           You should have received a copy of the GNU General Public License
           along with this program; if not, see http://www.gnu.org/licenses/.