$ crsctl check crs
CRS-4638: Oracle High Availability Services is online.
CRS-4537: Cluster Ready Services is online.
CRS-4529: Cluster Synchronization Services is online.
CRS-4533: Event Manager is online.
In 10g its not possible, where in 11g it is possible
[root@pic1]# crsctl start cluster -all
[root@pic2]# crsctl stop cluster –all
ocrconfig local=+DATA
local_only=FALSE
To start or stop Oracle Cluster ware on a specific node:
To enable or disable Oracle Cluster ware on a specific node:
crsctl enable crs (as root)
to disable
crsctl disable crs (as root)
Yes, as per documentation, if you have multiple voting disk you can add online, but if you have only one voting disk, by that cluster will be down as its lost you just need to start crs in exclusive mode and add the vote disk using
crsctl add vote disk <path>
Well, there is not much difference between 10g and 11gR (1) RAC.
But there is a significant difference in 11gR2.
Prior to 11gR1 (10g) RAC, the following were managed by Oracle CRS:
From 11gR2 (onwards) it’s completed HA stack managing and providing the following resources as like the other cluster software like VCS etc.
To check the viability of Cluster Synchronization Services (CSS) across nodes:
$ crsctl check cluster
CRS-4537: Cluster Ready Services is online.
CRS-4529: Cluster Synchronization Services is online.
CRS-4533: Event Manager is online.
To add a SCAN VIP resource:
To remove Cluster ware resources from SCAN VIPs:
To add a SCAN listener resource:
To remove Cluster ware resources from all SCAN listeners:
Software that provides various interfaces and services for a cluster. Typically, this includes capabilities that:
Basically Oracle kernel need to switched on with RAC On option when you convert to RAC, that is the difference as it facilitates few RAC bg process like LMON, LCK, LMD, LMS etc.
To turn on RAC:
Oracle RAC is composed of two or more database instances. They are composed of Memory structures and background processes same as the single instance database. Oracle RAC instances use two processes GES(Global Enqueue Service), GCS(Global Cache Service) that enable cache fusion.
Oracle RAC instances are composed of following background processes:
On a single node in the cluster, add the new global interface specification:
Verify the changes with oifcfg getif and then stop Cluster ware on all nodes by running the following command as root on each node:
Assign the network address to the new network adapters on all nodes using ifconfig:
Remove the former adapter/subnet specification and restart Cluster ware:
Crsctl manages cluster ware-related operations:
Srvctl manages Oracle resource–related operations:
ASM can use variable size data extents to support larger files, reduce memory requirements, and improve performance.
The data extent size is:
ASM stripes files using extents with a coarse method for load balancing or a fine method to reduce latency.
A scan listener is something that additional to node listener which listens the incoming db connection requests from the client which got through the scan IP, it got endpoints configured to node listener where it routes the db connection requests to particular node listener.
Grid Naming service is alternative service to DNS , which will act as a sub domain in your DNS but managed by Oracle, with GNS the connection is routed to the cluster IP and manages internally.
$ cluvfy comp nodecon -n all –verbose
ASM imposes the following limits:
ASM file size limits (database limit is 128 TB):
In 11gr2 the listeners will run from Grid Infrastructure software home
With Oracle Cluster ware 11g release 2, Oracle Universal Installer (OUI) detects when the minimum requirements for an installation are not met, and creates shell scripts, called fixup scripts, to finish incomplete system configuration steps. If OUI detects an incomplete task, then it generates fixup scripts (runfixup.sh). You can run the fixup script after you click the Fix and Check Again Button.
The Fixup script does the following:
If necessary sets kernel parameters to values required for successful installation, including:
Sets permissions on the Oracle Inventory (central inventory) directory. Reconfigures primary and secondary group memberships for the installation owner, if necessary, for the Oracle Inventory directory and the operating system privileges groups.
VIP, Node apps etc.
crsctl stop cluster (possible only from 11gr2), please note crsctl commands becomes global now, if you do not specify node specifically the command executed globally
for example:
The cluster stack will be down due to the fact that cssd is unable to maintain the integrity, this is true in 10g, from 11gR2 onwards, the crsd stack will be down, the house still up and running. You can add the OCR back by restoring the automatic backup or import the manual backup.