RAC Cheat Sheet


GCSGlobal Cache Servicesin memory database containing current locks and awaiting locks, also known as PCM
GESGlobal Enqueue Servicescoordinates the requests of all global enqueues uses the GCS, also known as non-PCM
GRDGlobal Resource Directoryall resources available to the cluster (formed and managed by GCS and GES), see GRDfor more details
GRMGlobal Resource Managerhelps to coordinate and communicate the locks requests between Oracle processes
GSDGlobal Services Daemonruns on each node with one GSD process per node. The GSD coordinates with the cluster manager to receive requests from clients such as the DBCA, EM, and the SRVCTL utility to execute administrative job tasks such as instance startup or shutdown. The GSD is not an Oracle instance background process and is therefore not started with the Oracle instance
PCM (IDLM)Parallel Cache Managementformly know as (integrated) Distributed Lock Manager, its another name for GCS
Resourcen/ait is a identifiable entity it basically has a name or a reference, it can be a area in memory, a disk file or an abstract entity
Resource (Global)n/aa resource that can be accessed by all the nodes within the cluster examples would be the following
  • Data Buffer Cache Block
  • Transaction Enqueue
  • Database Data Structures
LVBLock Value Blockcontains a small amount of data regarding the lock
TRFCTraffic Controllercontrols the DLM traffic between instances (messaging tickets)
Files and Directories
Files and Directories
$ORA_CRS_HOME/cdata/<cluster_name>OCR backups (default location)
$ORA_HOME/log/<hostname>/client/ocrconfig_<pid>.logOCR command log file
$ORA_CRS_HOME/crs/logcontains trace files for the CRS resources
$ORA_CRS_HOME/crs/initcontains trace files for the CRS daemon during startup, a good place to start
$ORA_CRS_HOME/css/logcontains cluster reconfigurations, missed check-ins, connects and disconnects from the client CSS listener. Look here to obtain when reboots occur
$ORA_CRS_HOME/css/initcontains core dumps from the cluster synchronization service daemon (OCSd)
$ORA_CRS_HOME/evm/loglogfiles for the event volume manager and eventlogger daemon
$ORA_CRS_HOME/evm/initpid and lock files for EVM
$ORA_CRS_HOME/srvm/loglogfiles for Oracle Cluster Registry (OCR)
$ORA_CRS_HOME/loglog fles for Oracle clusterware which contains diagnostic messages at the Oracle cluster level
Useful Views/Tables
GCS and Cache Fusion Diagnostics
v$cachecontains information about every cached block in the buffer cache
v$cache_transfercontains information from the block headers in SGA that have been pinged at least once
v$instance_cache_transfercontains information about the transfer of cache blocks through the interconnect
v$cr_block_servercontains statistics about CR block transfer across the instances
v$current_block_servercontains statistics about current block transfer across the instances
v$gc_elementcontains one-to-one information for each global cache resource used by the buffer cache
GES diagnostics
v$lockcontains information about locks held within a database and outstanding requests for locks and latches
v$ges_blocking_enqueuecontains information about locks that are being blocked or blocking others and locks that are known to the lock manager
v$enqueue_statisticscontains details about enqueue statistics in the instance
v$resource_limitsdisplay enqueue statistics
v$locked_objectcontains information about DML locks acquired by different transactions in databases with their mode held
v$ges_statisticscontains miscellaneous statistics for GES
v$ges_enqueuecontains information about all locks known to the lock manager
v$ges_convert_localcontains information about all local GES operations
v$ges_convert_remotecontains information about all remote GES operations
v$ges_resourcecontains information about all resources known to the lock manager
v$ges_misccontains information about messaging traffic information
v$ges_traffic_controllercontains information about the message ticket usage
Dynamic Resource Remastering
v$hvmaster_infocontains information about current and previous master instances of GES resources in relation to hash value ID of resource
v$gcshvmaster_infothe same as above but globally
v$gcspfmaster_infoconatins information about current and previous masters about GCS resources belonging to files mapped to a particular master, including the number of times the resource has remastered
Cluster Interconnect
v$cluster_interconnectscontains information about interconnects that are being used for cluster communication
v$configured_interconnectssame as above but also contains interconnects that AC is aware off that are not being used
v$serviceservices running on an instance
x$kjmsdpdisplay LMS daemon statistics
x$kjmddpdisplay LMD daemon statistics
Useful Parameters
cluster_interconnectsspecify a specific IP address to use for the inetrconnect
_gcs_fast_configenables fast reconfiguration for gcs locks (true|false)
_lm_master_weightcontrols which instance will hold or (re)master more resources than others
_gcs_resourcescontrols the number of resources an instance will master at a time
_lm_ticketscontrols the number of message tickets
_lm_ticket_active_sendbackcontrols the number of message tickets (aggressive messaging)
_db_block_max_cr_dbalimits the number of CR copies per DBA on the buffer cache (see grd)
_fairness_thresholdused when too many CR requested arrive for a particular buffer and the block becomes disowned (see grd)
_gc_affinity_timespecifies interval minutes for reamstering
_gc_affinity_limitdefines the number of times a instance access the resource before remastering
_gc_affinity_minimumdefines the minimum number of times a instance access the resource before remastering
_lm_file_affinitydisables dynamic remastering for the objects belonging to those files
_lm_dynamic_remasteringenable or disable remastering
_gc_defer_timedefine the time by which an instance deferred downgrading a lock (see Cache Fusion)
_lgwr_async_broadcastchange the SCN boardcast method (see troubleshooting)

Oracle RAC Daemons and Processes
OPROCdProcess Monitorprovides basic cluster integrity services
EVMdEvent Managementspawns a child process event logger and generates callouts
OCSSdCluster Synchronization Servicesbasic node membership, group services, basic locking
CRSdCluster Ready Servicesresource monitoring, failover and node recovery
Lock Manager Server process - GCSthis is the cache fusion part, it handles the consistent copies of blocks that are tranferred between instances. It receives requests from LMD to perform lock requests. I rools back any uncommitted transactions. There can be upto ten LMS processes running and can be started dynamically if demand requires it.
they manage lock manager service requests for GCS resources and send them to a service queue to be handled by the LMSn process. It also handles global deadlock detection and monitors for lock conversion timeouts.
Lock Monitor Process - GESthis process manages the GES, it maintains consistency of GCS memory in case of process death. It is also responsible for cluster reconfiguration and locks reconfiguration (node joining or leaving), it checks for instance deaths and listens for local messaging.
A detailed log file is created that tracks any reconfigurations that have happened.
Lock Manager Daemon - GESthis manages the enqueue manager service requests for the GCS. It also handles deadlock detention and remote resource requests from other instances.
Lock Process - GESmanages instance resource requests and cross-instance call operations for shared resources. It builds a list of invalid lock elements and validates lock elements during recovery.
Diagnostic DaemonThis is a lightweight process, it uses the DIAG framework to monitor the healt of the cluster. It captures information for later diagnosis in the event of failures. It will perform any neccessary recovery if an operational hang is detected.
General Administration
Managing the Cluster
starting/etc/init.d/init.crs start

crsctl start crs
stopping/etc/init.d/init.crs stop

crsctl stop crs
enable/disable at boot time/etc/init.d/init.crs enable
/etc/init.d/init.crs disable

crsctl enable crs
crsctl disable crs
Managing the database configuration with SRVCTL
start all instancessrvctl start database -d <database> -o <option>

Note: starts listeners if not already running, you can use the -o option to specify startup/shutdown options

stop all instancessrvctl stop database -d <database> -o <option>

Note: the listeners are not stopped, you can use the -o option to specify startup/shutdown options

start/stop particular instancesrvctl [start|stop] database -d <database> -i <instance>,<instance>
display the registered databasessrvctl config database
statussrvctl status database -d <database>
srvctl status instance -d <database> -i <instance>,<instance>
srvctl status service -d <database>
srvctl status nodeapps -n <node>
srvctl status asm -n <node>
stopping/startingsrvctl stop database -d <database>
srvctl stop instance -d <database> -i <instance>,<instance>
srvctl stop service -d <database> -s <service>,<service> -i <instance>,<instance>
srvctl stop nodeapps -n <node>
srvctl stop asm -n <node>

srvctl start database -d <database>
srvctl start instance -d <database> -i <instance>,<instance>
srvctl start service -d <database> -s <service>,<service> -i <instance>,<instance>
srvctl start nodeapps -n <node>
srvctl start asm -n <node>
adding/removingsrvctl add database -d <database> -o <oracle_home>
srvctl add instance -d <database> -i <instance> -n <node>
srvctl add service -d <database> -s <service> -r <preferred_list>
srvctl add nodeapps -n <node> -o <oracle_home> -A <name|ip>/network
srvctl add asm -n <node> -i <asm_instance> -o <oracle_home>

srvctl remove database -d <database> -o <oracle_home>
srvctl remove instance -d <database> -i <instance> -n <node>
srvctl remove service -d <database> -s <service> -r <preferred_list>
srvctl remove nodeapps -n <node> -o <oracle_home> -A <name|ip>/network
srvctl asm remove -n <node>
OCR utilities
log file$ORA_HOME/log/<hostname>/client/ocrconfig_<pid>.log

Note: will return the OCR version, total space allocated, space used, free space, location of each device and the result of the integrity check
dump contentsocrdump -backupfile <file>

Note: by default it dumps the contents into a file named OCRDUMP in the current directory
export/importocrconfig -export <file>

ocrconfig -restore <file>
backup/restore# show backups
ocrconfig -showbackup

# to change the location of the backup, you can even specify a ASM disk
ocrconfig -backuploc <path|+asm>

# perform a backup, will use the location specified by the -backuploc location
ocrconfig -manualbackup

# perform a restore
ocrconfig -restore <file>

# delete a backup
orcconfig -delete <file>

Note: there are many more option so see the ocrconfig man page
add/remove/replace## add/relocate the ocrmirror file to the specified location
ocrconfig -replace ocrmirror '/ocfs2/ocr2.dbf'

## relocate an existing OCR file
ocrconfig -replace ocr '/ocfs1/ocr_new.dbf'

## remove the OCR or OCRMirror file
ocrconfig -replace ocr
ocrconfig -replace ocrmirror
CRS Administration
CRS Administration
starting## Starting CRS using Oracle 10g R1
not possible
## Starting CRS using Oracle 10g R2
$ORA_CRS_HOME/bin/crsctl start crs
stopping## Stopping CRS using Oracle 10g R1
srvctl stop database -d <database>
srvctl stop asm -n <node>
srvctl stop nodeapps -n <node>
/etc/init.d/init.crs stop

## Stopping CRS using Oracle 10g R2
$ORA_CRS_HOME/bin/crsctl stop crs
disabling/enabling## use to stop CRS restarting after a reboot

## Oracle 10g R1
/etc/init.d/init.crs [disable|enable]

## Oracle 10g R2
$ORA_CRS_HOME/bin/crsctl [disable|enable] crs
checking$ORA_CRS_HOME/bin/crsctl check crs
$ORA_CRS_HOME/bin/crsctl check evmd
$ORA_CRS_HOME/bin/crsctl check cssd
$ORA_CRS_HOME/bin/crsctl check crsd
$ORA_CRS_HOME/bin/crsctl check install -wait 600
Resource Applications (CRS Utilities)
create profile$ORA_CRS_HOME/bin/crs_profile
register/unregister application$ORA_CRS_HOME/bin/crs_register
Start/Stop an application$ORA_CRS_HOME/bin/crs_start
Resource permissions$ORA_CRS_HOME/bin/crs_getparam
Relocate a resource$ORA_CRS_HOME/bin/crs_relocate
member number/nameolsnodes -n
local node nameolsnodes -l
activates loggingolsnodes -g
Oracle Interfaces
displayoifcfg getif
deleteoicfg delig -global
setoicfg setif -global <interface name>/<subnet>:public
oicfg setif -global <interface name>/<subnet>:cluster_interconnect
Global Services Daemon Control
startinggsdctl start
stoppinggsdctl stop
statusgsdctl status
Cluster Configuration (clscfg is used during installation)
create a new configurationclscfg -install
upgrade or downgrade and existing configurationclscfg -upgrade
clscfg -downgrade
add or delete a node from the configurationclscfg -add
clscfg -delete
create a special single-node configuration for ASMclscfg -local
brief listing of terminology used in the other nodesclscfg -concepts
used for tracingclscfg -trace
helpclscfg -h
Cluster Name Check
print cluster namecemulto -n

Note: in Oracle 9i the ulity was called "cemutls"
print the clusterware versioncemulto -w

Note: in Oracle 9i the ulity was called "cemutls"
Node Scripts
Add Nodeaddnode.sh

Note: see adding and deleting nodes
Delete Nodedeletenode.sh

Note: see adding and deleting nodes
displaying statisticsSQL> column current_utilization heading current
SQL> column max_utilization heading max_usage
SQL> column initial_allocation heading initial
SQL> column resource_limit format a23;

SQL> select * from v$resource_limit;
Messaging (tickets)
ticket usageselect local_nid local, remote_nid remote, tckt_avail avail, tckt_limit limit, snd_q_len send_queue, tckt_wait waiting from v$ges_traffic_controller;
dump ticket informationSQL> oradebug setmypid
SQL> oradebug unlimit
SQL> oradebug lkdebug -t
Lighwork Rule and Fairness Threshold
downconvertselect cr_requests, light_works, data_requests, fairness_down_converts from v$cr_block_server;

Note: lower the _fairness_threshold if the ratio goes above 40%, set to 0 if the instance is a query only instance.
force dynamic remastering (DRM)## Obtain the OBJECT_ID form the below table
SQL> select * from v$gcspfmaster_info;
## Determine who masters it
SQL> oradebug setmypid
SQL> oradebug lkdebug -a <OBJECT_ID>

## Now remaster the resource
SQL> oradebug setmypid
SQL> oradebug lkdebug -m pkey <OBJECT_ID>
Enable tracing $ export SRVM_TRACE=true
Disable tracing $ export SRVM_TRACE=""
Voting Disk
addingcrsctl add css votedisk <file>
deletingcrsctl delete css votedisk <file>
queryingcrsctl query css votedisk


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