How to recreate the standby redologs in dataguard blogger. You can use operating system commands to relocate redo logs, then use the alter database statement to make their new names locations known to the database. Standby database needs standby redo logs for 2 primary threads. This article is a repeat of the manual 11gr2 data guard setup described here, but here the. Steps to recreate standby log files in data guard about. See oracle database administrators guide for more information about redo logs and archive logs, and section 6. Arcn then writes the redo to the archived redo log location on the standby server.
How to install oracle 11g grid infrastructure software and step by step process for asm configuration. The standby archival operation occurs automatically, even if the standby database is not in archivelog mode. This process is only possible if the database is running in archivelog mode. Home database oracle database online documentation 11g release 1 11. Oracle dataguard how to resize redo log and standby redo. Configure backups on tape library through networker.
Redo logs in an oracle database dbarch video 11 youtube. The software which oracle corporation markets as oracle data guard forms an extension to. The standby redo logs would not be used on the primary database until there is a switchover operation performed and the primary database starts behaving as a standby database. Without standby redo logs, an archived redo log is created by the rfs. Oracle provides the redo logs to enable rollforward operations, and proper mirroring of redo log files is an oracle best practice. The standby redo logs also needs to be created on the primary database, but this is not mandatory. Without specifying lgwr or arch, lgwr is the default. Oracle writes all statements except, select statement, to the logfiles. How to droprename standby redolog file in oracle 11g. Physical standby database using hotbackup catch dba. How to resolve mrp stuck issues on a physical standby. Miblanco oracle rac on exacc now ensures the availability and scalability for daytoday operations with oracle active data guard in gold maa configuration acting as the analytics backbone as well as the disaster failover. For administrative ease, oracle recommends that all redo log files in the redo log at the redo source database and the standby redo log at a redo transport destination be of the same size. The value is an oracle net service name, which is assumed to be configured properly on the fal server system to point to the fal client standby database.
March 21, 2016 june 25, 2016 stevecao 2 comments on steps to recreate standby log files in data guard. Oracle database lets you save filled groups of redo log files to one or more offline destinations, known collectively as the archived redo log, or more simply the archive log. Once, i receive the email regarding the resize of the redo log file. You will want to have standby redo logs srls on the standby database. The process of turning redo log files into archived redo log files is called archiving. I needed to resize the redo log as it takes about 4 days to do a log switch. Mohammed a khan oracle database administrator charter. The standby redo log must have at least one more redo log group than the redo log on the redo source database. If the standby redo logfile is unassigned, the value unassigned will be displayed. This avoids most of the storage and processing expense of another fully configured standby database. How to droprename standby redolog file in oracle 11g while performing the dataguard broker, we need to drop the standby database while switchover the standby. How to recreate the standby redologs in dataguard q. Data guard provides a comprehensive set of services that create, maintain, manage, and monitor one or more standby databases to enable production oracle databases to survive disasters and data corruptions. Helps with initial instantiation of a data guard standby does not require oracle database 11g.
Thats a lot of steps, but its not too hard to understand. Create standby redo logs on the primary database in case of switchovers. This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time skip to content. How to resize redo log and standby redo log in oracle dataguard environment. Essentially, the standby redo logs are populated with. Perform an oracle database 11g installation software and db installed for a single server environment or oracle database 11g installation software and db installed on 1 server and oracle database 11g software only on 2nd server for a dual server environment. Resizing redo logs in a dataguard envrionment physical. Recovering after the loss of all members of an online redo log group. See also chapter 15, using oracle managed files for information about creating an archived redo log that is both created and managed by the oracle database server oracle real application clusters administration and deployment guide for information specific to archiving in the oracle real application clusters environment. Oracle data guard ensures high availability, data protection, and disaster recovery for enterprise data. If a media failure damages all members of an online redo log group, then different scenarios can occur depending on the type of online redo log group affected by the failure and the archiving mode of the database. Our otherwise very good online documentation says rman automatically creates the standby redo log files on the standby database.
Redo data cannot be written to the standby redo log and rfs368. To protect against a failure involving the redo log itself, oracle database can multiplex the redo log so that two or more identical copies of the online redo log can be maintained on different disks. This destination type is used for temporary offsite storage of archived redo log files. Resize mirrored online redo logs and mirrored standby redo logs in asm plus single instance database having files on local linux file system. Oracle 11g 12c database, grid infrastructure, rac deployment. Standby redo logs are only used if you have the lgwr as transport mode to remote standby database. The advantage of having standby redo logs slr is that every records written into the online redologs of the primary database is transferred to the standby database and written into the standby redo logs at the same time. An archive gap is a range of missing redo on the standby site that prevents log apply services to proceed. Explains the structure of a physical standby database with oracle data guard in an sap. Oracle 8i oracle 9i oracle 10g oracle 11g oracle 12c oracle c oracle 18c oracle 19c miscellaneous plsql sql oracle rac oracle apps weblogic linux mysql. Why someone want to change the size of standby redo log. Every oracle database must have at least 2 redo logfile groups. Sql alter database recover managed standby database using current logfile disconnect. Oracle manual standby no dataguard this entry is outdated.
Oracle data guard is a technology which helps you protect against planned and unplanned downtime. Standby redo logs must be archived on standby database before the data can be applied to the standby database. This is done because oracle performs deferred batch writes i. Hello, i am starting on implementing an 11g data guard configuration here. You will understand how oracle instance uses redo buffers and logwriter to keep the redo in redo logs. Data guard maintains these standby databases as transactionally consistent copies. Oracle database 11g active data guard hands on workshop. If so, then please compare whether it has the same size on the standby as it is on the primary by cksum command. Master oracle 11g data guard video course teaches you how to implement oracle data guard in real time environment. It is not possible to resize the redo log or standby redo log srl. The course briefly discuss about the need of oracle data guard, oracle high availability and how to setup oracle data guard. Leveraging logical standby databases in oracle 11g data guard.
Create standby log file groups on the primary database for switch overs. The redo log is used to recover a database after hardware, software, or media failure. Automatic creation of standby logs with rman duplicate. Here is a snippet of the size of the redo logs online and standby redo. One thing mentioned in the dg course and a whole bunch of documents i found online is the setup of the standby redo log files. Once the archived redo log is completed, the managed recovery process mrp0 sends the redo to the standby instance for applying the transaction. The recommended log switch frequency is at least once an hour. Oracle data files oracle instance inmemory primary database oracle data files. Oracle recommends using an archived redo log repository.
This is not the same level of redundancy or availability of oracle rac, but getting close. Linkedin oracle maa with oracle goldengate and active data guard, goldengate, and rman. I tried to implement a manual standby in 11g with oracle linux. Oracle 11g is that if srls have already been configured on the primary. Download ebook oracle 11g documentation oracle 11g documentation when people should go to the ebook stores, search opening by. The exercises are set up to walk you through oracle database 11g active data guard using sqlplus and the broker working with a physical standby redo apply database using active data guard to read your data as redo is being applied while maintaining data protection. Top oracle database 11g high availability best practices.
Recovery data oracle instance inmemory remote replica 3 2 1 sync or async recovery data. Standby redo log files can be written using synchronous lgwr sync or asynchronous redo transmission lgwr async. Noaffirm means the redo transport will be acknowledged before writing the received redo to disk standby redo logs async noaffirm means the log transfer method is arch right. You can read about the cascaded redo log solution in standby database redo apply lag time about one month. Active data guard 11g secure access to realtime data ingest geospatial data 10 tb primary. This procedure is necessary, for example, if the disk currently used for some redo log files is going to be removed, or if datafiles and a number of redo log files are stored on the same disk and. Top oracle database 11g high availability best practices joseph meeks director, product management. Managing the redo log oracle dba redo log management. Although the standby redo log is only used when the database is running in the standby role, oracle recommends that you create a standby redo log on the primary database so that the primary database can switch over quickly to the standby role without the need for additional dba intervention. This paper complements the standard documentation by the way that it steps through the whole process of building a complete environment where both the primary and physical standby systems are based on oracle rac. While performing the dataguard broker, we need to drop the standby database while switchover the standby. If you do not have the required archived redo log files to recover your database, you will probably be fired for cause, but in case your job is spared, you need to consider the problem of lost redo log files.
Through the use of standby redo log files, data guard can minimize data loss. The course and all the papers always talk about one member per standby redo log group. This chapter describes how to configure and monitor oracle redo transport. This typically happens when the standby site is unable to receive redo from the primary database or the redo information is not available on the. You can use any backup copy of the primary database to create the physical standby database if the necessary archived redo log files to completely recover the. This video explains the concepts of redo log groups and files in an oracle database. Successfully implemented physical standby database using oracle data guard feature for high availability configuration. Oracle dataguard setup 11g, broker dgmgrl, automatic switchover, standby redo logs. Data guard physical standby setup in oracle database 11g. It applies the redo it receives from primary, but does the changes made to standby database are logged in redo and hence archive log as.