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difference between ocr and voting disk

Added on Sep 7 It was introduced in 11gR2, and is not shared by any other node in the cluster. If necessary, you can dynamically add or replace voting disks after you complete the Oracle Clusterware installation process without stopping the cluster. CSSD processes (Cluster Services Synchronization Daemon) monitor the health of RAC nodes employing two distinct heartbeats: Network heartbeat and Disk heartbeat. OCR manages Oracle Clusterware and Oracle RAC database configuration information, OLR resides on every node in the cluster and manages Oracle Clusterware configuration information for each particular node, Voting disks manage information about node membership. For example: The default backup location for the OLR is in the path Grid_home/cdata/host_name. Basic information about the resources, their location, permissions, current value, type, state, etc. Oracle By default, redo logs and control files are mirrored to both the DATA and FRA diskgroups. on Oct 5 2010. It records the data where marks are made on the form. The CRSD process that creates the backups also creates and retains an OCR backup for each full day and at the end of each week. such as Oracle RAC databases, listeners, virtual IP addresses (VIPs), and services and any applications. Mount and check status Diskgroup in all Nodes Recover the Oracle voting disk when its For example, if the OCR location is /dev/sde1, then use the command syntax ocrconfig -repair -add /dev/sde1 on this node to repair OCR on that node. Its application is in surveys, answer sheets, questionnaires and ballots. However, overriding the protection mechanism can result in the loss of data that was not available when the previous known good state was created. WebHello Friends,Here with one more topic on database administration guide. Run the following command to verify the current running version: Use the Oracle ASM Configuration Assistant (ASMCA) to configure and start Oracle ASM on all nodes in the cluster. The text to speech can be used by them. OCR You can inspect a backup using the OCRDUMP utility. Check the location of OCR Disk from GRID Home with root user. Rely on OCR Backups Since 11g (11.2), the voting disk data is automatically backed up in OCR as part of any configuration change and is automatically restored to any voting disk added. Check the Voting Disk Location At least two OCR locations if OCR is configured on mirrored hardware or third-party mirrored volumes. My test systems OLR files has about 651 keys. With the Oracle Clusterware storage residing in an Oracle ASM disk group, you can manage both database and clusterware storage using Oracle Enterprise Manager. Will install binaries on local disk and use SAN for Voting disk, OCR and ASM. If you choose to store your voting disks in Oracle ASM, then Oracle ASM stores all the voting disks for the cluster in the disk group you choose. This section describes how to manage OCR and the Oracle Local Registry (OLR) with the following utilities: OCRCONFIG, OCRDUMP, and OCRCHECK. FAILGROUP fg02 DISK '/dev/oracleasm/disks/OCR_DISK12' Healthy nodes will have continuous network & disk heartbeats exchanged between the nodes. Voting disks contain static and dynamic data. Then each node uses its local copy of OCR and the local CRSd process to access it and communicate via the same local process if they need more updates from the physical OCR file. These files can be stored either in ASM or in shared storage. Oracle Cluster Registry (OCR) and Oracle Local Registry (OLR) Oracle Cluster Registry (OCR) and Oracle Local Registry (OLR) are two very important components of a Grid Infrastructure that help manage the cluster resources. 1. OCR stores configuration information in a series of key-value pairs in a tree structure. Generally, the following information is found in the OLR. The destination of OCR file has been replaced. What is voting disks in RAC 11gR2 can have upto five mirrored copies of OCR. There are a few different scenarios possible with missing heartbeats:1. ERROR: Unable to verify the graphical display setup. Thus heartbeat of various nodes is recorded at different offsets in the voting disk. Restore Voting Disk Since we have restored OCR, we restored voting file as well. OCR is used in a variety of applications, such as scanning documents and recognizing text in images. OMR technology scans a printed form and reads from predefined positions. on Oct 5 2010. To downgrade, follow the downgrade instructions for each component and also downgrade OCR using the ocrconfig -downgrade command. A voting disk is a file that manages information about node membership. It contains the following information shared across the nodes in the cluster. This is widely used for processing the large number of hand-filled forms which have to be processed quickly and with great accuracy. Move the OCR to new diskgroup. WebOracle Clusterware includes two important components that manage configuration and node membership: Oracle Cluster Registry (OCR), which also includes the local component Oracle Local Registry (OLR), and voting files. [root@NODE01 ~]# /u01/app/11.2.0.4/grid/bin/ocrconfig -delete +OCRVD_DG, 11. Disk Group ocr_newdg is running on node01,node02, 8. You cannot directly influence the number of voting disks in one disk group. You can run this command more than once if there is more than one OCR location configured. Oracle ASM on ScaleIO Best Practices - Dell Technologies For example, the database cannot be started until the asm resource has come up, or the service resource doesnt start until the database has been started. Restoring the Oracle Cluster Registry on Linux or UNIX Systems, Restoring the Oracle Cluster Registry on Windows Systems, Restoring the Oracle Cluster Registry in an Oracle Restart Environment. To migrate OCR to Oracle ASM using OCRCONFIG: Ensure the upgrade to Oracle Clusterware 11g release 2 (11.2) is complete. If you cannot mount the disk group locally, then run the following SQL*Plus command: Optionally, if you want to restore OCR to a raw device, then you must run the ocrconfig -repair -replace command as root, assuming that you have all the necessary permissions on all nodes to do so and that OCR was not previously on Oracle ASM. While marking their own presence, all the nodes also register the information about their communicability with other nodes in the voting disk. This is called NETWORK HEARTBEAT. Please contact us at contactus@smarttechways.com, How to get DDL of Tablespace present in OracleDatabase, Follow Smart way of Technology on WordPress.com, Exclude/Include option in EXPDP and IMPDP Datapump, Create & grant permission to directory in Oracle, Check the Undo tablespace Usage in Oracle, Check datafiles and tablespace information in Oracle, Check the Patch Applied to the Oracle Database, Stop the EXPDP/IMPDP Datapump Job in Oracle, Find top CPU Consuming Session or SQLs query in Oracle. col header_status for a20 You cannot add a voting disk to a cluster file system if the voting disks are stored in an Oracle ASM disk group. The visually impaired people find it useful. "OCRDUMP Utility Syntax and Options" for more information about the OCRDUMP utility, "Using the OCRCHECK Utility" for more information about the OCRCHECK utility. Optical Mark Reader (OMR) is the technology of electronically extracting data from marked fields such as checkboxes or bubbles from pre-printed forms. If we are not using a voting disk, then due to network failure, nodes are neither able to communicate with each other nor synchronize with the database, this situation is called a cluster SPLIT-BRAIN problem. It stands for Optical Character Reader or Optical Character Recognition. If it cannot access the minimum of voting disks, then it is evicted/removed from the cluster. However, Oracle recommends using several failure groups. For eg, if you have 5 voting disks, a node must be able to access at least 3 of the voting disks. In a nutshell, OCR is used by CRSd and OLR by the OHASd. Restore Voting Disk Since we have restored OCR, we restored voting file as well. The Oracle Clusterware installation process creates the voting disk and the OCR on a shared storage volume. user13389425 Sep 7 2010 edited Sep 7 2010. OLR is a registry similar to OCR located on each node in a cluster, but contains information specific to each node. This step is necessary only if OCR is also corrupted or otherwise unavailable, such as if OCR is on Oracle ASM and the disk group is no longer available. (LogOut/ The voting disk is a file that manages information about node membership, and the OCR is a file that manages the cluster and Real Application Clusters (RAC) database configuration information. In such cases, Oracle Database displays an alert message in either Oracle Enterprise Manager, the Oracle Clusterware alert log files, or both. OCR stores Oracle Clusterware and Oracle RAC database configuration information 2) CSSD process on every node makes entries in the voting disk to ascertain the membership of the node. This chapter includes the following topics: Managing Oracle Cluster Registry and Oracle Local Registry. If the configurations do not match, run ocrconfig -repair. WebOracle Clusterware includes two important components that manage configuration and node membership: Oracle Cluster Registry (OCR), which also includes the local component Oracle Local Registry (OLR), and voting files. To add a new disk and remove the existing disk, run the following command, replacing the path_to_voting_diskB variable with the fully qualified path name of voting disk B: The -purge option deletes existing voting disks. If you run the ocrconfig -add | -repair | -replace command, then the device, file, or Oracle ASM disk group that you are adding must be accessible. You can have up to five OCR locations. It is the rapid method of data entry. To replace all voting disks not stored in Oracle ASM with voting disks managed by Oracle ASM in an Oracle ASM disk group, run the following command: Modifying voting disks that are not stored on Oracle ASM: To display the voting disk FUID and file path of each current voting disk, run the following command: This command returns a disk sequence number, the status of the disk, the FUID, and the path of the disk and no name of an Oracle ASM disk group. --add the new diskgroup with root user. Network heartbeat is successful, but disk heartbeat is missed.2. The heartbeat counter increments every second on every write call. Voting disks/files are just like attendance registers where you have nodes mark their attendance (heartbeats). When using ScaleIO snapshots, it can be beneficial to snapshot the DATA and FRA diskgroups independently. Successfully replaced voting disk group with +OCR_NEWDG. OCR and voting disk difference between OCR and voting disk If the original OCR location does not exist, then you must create an empty (0 byte) OCR location with appropriate permissions before you run the ocrconfig -add or ocrconfig -replace commands. Managing Oracle Cluster Registry and Voting Disks Below is a table of differentiation between Optical Mark Reader (OMR) and Optical Character Reader (OCR): Difference between Optical Character Recognition (OCR) and Magnetic Ink Character Reader (MICR), Difference Between Electric Potential and Potential Difference, Difference between EMF and Potential Difference, Difference between Voltage Drop and Potential Difference, Difference between Difference Engine and Analytical Engine, Difference Between Single and Double Quotes in Shell Script and Linux, Difference between Time Tracking and Time and Attendance Software, Difference and Similarities between PHP and C, Similarities and Difference between Java and C++. If the crsd process running on the node affected by the Oracle ASM instance failure is the OCR writer, the majority of the OCR locations are stored in Oracle ASM, and you attempt I/O on OCR during the time the Oracle ASM instance is down on this node, then crsd stops and becomes inoperable. Perform the following procedure to overwrite OCR if a node cannot start and if the alert log contains CLSD-1009 and CLSD-1011 messages. Using the crsctl replace votedisk command, you can move a given set of voting disks from one Oracle ASM disk group into another, or onto a certified file system. Oracle recommends just two diskgroups by default: By default, redo logs and control files are mirrored to both the DATA and FRA diskgroups. Ensure that the Oracle ASM disk group that you specify exists and is mounted. Change). Begin to start Oracle Clusterware by running the following command as root on all of the nodes: Verify OCR integrity of all of the cluster nodes that are configured as part of your cluster by running the following CVU command: Use the following procedure to restore OCR on Windows systems: Stop Oracle Clusterware by running the following command as a member of the Administrators group on all of the nodes: If the preceding command returns any error due to OCR corruption, stop Oracle Clusterware by running the following command as a member of the Administrators group on all of the nodes: Start the Oracle Clusterware stack on one node in exclusive mode by running the following command as a member of the Administrators group: Restore OCR with the OCR backup file that you identified in "Listing Backup Files" by running the following command as a member of the Administrators group: Make sure that the OCR devices that you specify in the OCR configuration exist and that these OCR devices are valid. For any work, queries and help. OCR has a mechanism that prevents data loss due to accidental overwrites. CSS service is sending heartbeat messages through the network and voting disk.In a situation, when due to private network failure, nodes are not able to synchronize I/O to the shared disks, Therefore some of the nodes will be going to the offline stage. Oracle If the OCR mirror and OCR have been deleted, then it may be faster to restore the OCR using the OCR backups. acknowledge that you have read and understood our, Data Structure & Algorithm Classes (Live), Data Structures & Algorithms in JavaScript, Data Structure & Algorithm-Self Paced(C++/JAVA), Full Stack Development with React & Node JS(Live), Android App Development with Kotlin(Live), Python Backend Development with Django(Live), DevOps Engineering - Planning to Production, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Interview Preparation For Software Developers. A high redundancy disk group must contain at least three failure groups. Begin to start Oracle Clusterware by running the following command as a member of the Administrators group on all of the nodes: Run the following Cluster Verification Utility (CVU) command to verify OCR integrity of all of the nodes in your cluster database: OCR is present for backward compatibility. Despite the fact that crsctl query css votedisk reports zero vote disks in use, Oracle Clusterware remembers the fact that Oracle ASM was in use and the replace verb is required. To migrate voting disks from Oracle ASM to an alternative storage device, specify the path to the non-Oracle ASM storage device with which you want to replace the Oracle ASM disk group using the following command: You can run this command on any node in the cluster. For example, if two-way mirroring is specified for a file, then redundant copies of file extents must be stored in separate failure groups. You can find the location of the OCRFILE using one of the tow methods below. Optical Mark Reader (OMR) is the technology of electronically extracting data from marked fields such as checkboxes or bubbles from pre-printed forms. For example, if any node that is part of your current Oracle RAC cluster is shut down, then you must update the OCR configuration on the stopped node to let that node rejoin the cluster after the node is restarted. Mirroring can help prevent OCR from becoming a single point of failure. In a nutshell, OCR is used by CRSd and OLR by the OHASd. srvctl start diskgroup -g OCR_NEWDG -n NODE01,NODE02, --Check Status Please sign in to comment Perform the following procedure as the root user to remove an OCR location from your Oracle Clusterware environment: Ensure that at least one OCR location other than the OCR location that you are removing is online. Difference between OMR technology scans a printed form and reads from predefined positions. My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts. A small number of failure groups, or failure groups of uneven capacity, can create allocation problems that prevent full use of all of the available storage. Is it illegal to lie about a felony on an application? How do you write a referee report for a job application? This section includes the following topics: Adding an Oracle Cluster Registry Location, Removing an Oracle Cluster Registry Location, Replacing an Oracle Cluster Registry Location, Repairing an Oracle Cluster Registry Configuration on a Local Node, Overriding the Oracle Cluster Registry Data Loss Protection Mechanism. When exporting OCR, Oracle recommends including "ocr", the cluster name, and the timestamp in the name string. Is it illegal to lie about a felony on an application? --With Spmove command we will move the spfile If you did not store voting disks in Oracle ASM, then run the following command using the File Universal Identifier (FUID) obtained in the previous step: Stop the Oracle Clusterware stack as root: Restart the Oracle Clusterware stack in normal mode as root: You can add, remove, and migrate voting disks after you install Oracle Clusterware. Rely on OCR Backups Since 11g (11.2), the voting disk data is automatically backed up in OCR as part of any configuration change and is automatically restored to any voting disk added. Modifying voting disks that are stored in Oracle ASM. If OCR is stored in an Oracle ASM disk group with external redundancy, then Oracle recommends that you add another OCR location to another disk group to avoid the loss of OCR, if a disk fails in the disk group. By using our site, you This post has been answered by user00726 on Sep 7 2010. Make sure that xdpyinfo exist under PATH variable. List the Candidate Disk present for creating DISKGROUP. However, if you are unable to start any cluster node in your environment and if you can neither repair OCR nor restore access to all OCR locations, then you can override the protection mechanism. As a definitive verification that OCR failed, run ocrcheck and if the command returns a failure message, then both the primary OCR and the OCR mirror have failed. We and our partners share information on your use of this website to help improve your experience. External redundancy: A disk group with external redundancy can store only one voting disk, Normal redundancy: A disk group with normal redundancy stores three voting disks, High redundancy: A disk group with high redundancy stores five voting disks. Before you add, delete, replace, or restore voting disks, run the ocrcheck command as root. d) All nodes in the RAC cluster register their heartbeat information in the voting disks/files. Hope this sheds some light on what role OCR and OLR play in the Grid Infrastructure. Worked as a Development and Database Administrator. You can manually put the mirrored OCRs on a shared network file system (NFS), or on any cluster file system that is certified by Oracle.

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difference between ocr and voting disk