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Back ups

Former Member
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Hi,

May i know the main difference between ONLINE and OFLINE backups? and which one is preffereble in backup recoivery?

with regards,

Harish reddy

Accepted Solutions (1)

Accepted Solutions (1)

former_member190272
Active Contributor
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Hi

You can perform offline or online backups, as follows:

· Offline

During an offline backup the whole database, or parts of it, are unavailable for use. Offline backups are usually done at the database level. Offline backups at the tablespace or data file level are not advisable in an integrated environment like the SAP system, because the application modules require access to data in several tablespaces. If one of the main tablespaces is not available, most application modules cannot continue.

For an offline backup at the database level, you must close the database. Then you should do a full backup, that is, you must back up all data files, all online redo log files, and at least one control file.

The advantage of such a full backup is consistency. This backup could be restored and the database could then be opened without needing to do a recovery.

The major disadvantage is, obviously, that the database cannot be used while the backup is running.

BRBACKUP (the SAP backup tool) supports offline backups at all levels

Online

An online backup is more appropriate for large databases. An online backup can be a full or a partial backup. The backup includes all or some of the data files and a control file. For the backup to be usable, the offline redo log files generated while the backup was done also need to be available.

The advantage is that the database is available for normal use while the backup is taken. Online backup has the following disadvantages:

¡ Performance deteriorates

The DBMS performance worsens because more redo log information is generated while the backup is going on. Therefore you should do online backups during times of low system load. For example, an online backup running alongside a background job with batch input causes the run time of the background job to increase considerably.

¡ Backed up data files are inconsistent without the redo log files

If used for a recovery, the online backup must be supplemented with the redo log files archived during the backup. To make sure that the last online redo log file from the backup is safely archived, you should perform a redo log switch immediately after the backup. An online backup done with SAP’s BRBACKUP tool does this automatically.

You could perform an online backup by first running BRBACKUP to save data files and then running BRARCHIVE immediately afterwards, to save the archived redo log files belonging to the backup

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Thanks

Pankaj Kumar

Answers (2)

Answers (2)

Former Member
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Hi,

SAP Backup and Restore Information (MS SQL Server)

Use

The Backup/Restore Information transaction collects and presents information that is necessary to monitor database backups. It is an important source of information for the database administrator who has the task of supervising the execution of a defined backup strategy. Information on jobs scheduled in both the Planning Calendar and the SQL Server Enterprise Manager is displayed.

Prerequisites

Access the backup monitor with:

CCMS ® DB Administration ®Backup logs

Alternatively, enter the transaction code DB12. In case of non-MS SQL Server system, enter transaction DB12 with the suffix MSS, for example DB12_MSS. As of SAP Release 6.40, transaction DB12 has the interface to use multi-connect to connect to remote SAP and non-SAP systems. For more information, see Monitoring Remote SQL Server Databases.

Features

On the initial screen of the monitor, CCMS Monitoring Tool – DB12 (Backup/Restore Information), you can, at a glance, get a quick overview of important information related to SAP database backups. It shows:

· the last successful backups for the SAP, master and msdb databases and transaction logs

· the last SAP database size and duration of the backup job

· whether the SQL Server Agent is started or not

· the amount of log space allocated and how much is still free

· the Recovery interval, which specifies the maximum time that SQL Server should spend recovering after a database startup.

When you look at the amount of free space specified for logs, keep in mind that the data displayed reflects snapshots taken at a specific point in time. As logs are backed up and truncated at hourly intervals, a large amount of free space might be displayed because the log has just been truncated. For more information see Monitoring the SAP Log Disk.

Further functions available enable you to access technical details about past backups, restore operations and other actions planned in the DBA calendar:

Backup and Restore Information Options

Options

Comments

Backup history

Displays technical details about backups that have been executed, for example, the date and time of execution and the name of the physical device the backup was written to.

The pushbuttons in the menu let you choose different views. For example Logs Backups only displays the log backups. CCMS backups only displays backups scheduled in the Planning Calendar

Restoration history

Gives an overview of all past restore operations performed in the system. Full technical details are specified, including the size and type of backup restored, the date when the backup was created, the name of the device and volume used.

SQLAgent Scheduled Jobs

Displays the scheduled SQL Agent jobs for the next 30 days. The list contains job name, last run status, next run date, run schedule information etc.

SqlAgent Properties

Displays the properties set for the agent. At the operating system level, the SQLAgent is a service that is responsible for running backups that have been scheduled for a particular time. If you notice that backups are not being executed as planned, it is advisable to check the properties of the agent.

SQL Server jobs

Displays the technical details of all the jobs scheduled for the SQL Server. You can toggle between a view, which shows you All Database Jobs or CCMS jobs only which are scheduled in the Planning Calendar.

Select a job that has run and click History info to get more information about its execution.

Backup device list

Lists the backup devices available in the system. It shows whether the devices are disks or tapes, gives their logical names and their corresponding physical location.

Tapes needed for restore

Gives a continually updated overview of all the database and log backups that are currently required to perform a database restore operation. It shows all relevant technical details such as the time of the backups, their size and volume names. The information is the basis for performing a successful backup.

http://www.sap.com/search/index.epx?q1=backup&num=10

http://www.google.co.in/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=SAPBackups&spell=1

I hpe this wii be helpfull to you.

regards,

Balaram

Former Member
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online backup:no need to down the system.When the system is running u can perform the backup.

is a backup performed while the database is open and available for users

can be when the database is ARCHIVELOG mode.

offline backup: u need to take the down time for the system.

u need to shutdown the system and the perform.

is a backup performed while the database is off-line and unavailable to its users

can be taken regardless if the database is in ARCHIVELOG or NOARCHIVELOG mode.

reward points if helpful