I am new with ASM. we want to take ASM databse/instance backup.
can anyone have idea for ASM backup?
1. What components need to be backed up like ASM database/Instance/ ASM any files?
Please do needful.
You don't need to backup the ASM instance. There are no datafiles as part of the ASM instance.
You can backup the metadata for the disk groups using md_backup.
Oracle ASM is part of Grid Infrastructure and resides in its own ORACLE_HOME directory. Backup of the ASM software is the same as any other Oracle installation. The backup of any database using the ASM instance can be done using RMAN, which is the standard tool to backup all Oracle Databases. To access or copy individual files from the OS command line you can use the ASMCMD command. However, you cannot use TAR or any other backup software to access the data on ASM disks.
What type of backup will be taken by md_backup command?
will it take all files/directory/DG of ASM?
I still confused what type of metadata will be backed up?
There is two different things:
1: Backup of Database stored on ASM
2: Backup of ASM configuration
Backup of Database stored on ASM should be done using RMAN.
When you are not using ASM, how do you take a backup of Oracle Database using RMAN?
The same way you will take backup of database on stored on ASM. Using RMAN just run "Backup Database Plus Archivelog....".
About Backup ASM Configuration:
You can backup structure (metadata) of ASMDISK Group to a File, that can be used only to recreate ASMDISK GROUP and it's configuration (i.e No Data). To restore data you will need use RMAN as you would on normal filesystem.
How do I backup my ASM instance?
ASM has no files to backup, as its does not contain controlfile,redo logs etc.
ASM is a Filesystem that has it's particular concept.
Oracle Database are Files stored on filesystem supported by Oracle ( such as ASM, EXT3 and so on)
You must learn about two concepts that are different from one to another.
Thank you Ashish for your prompt response.
Now i got idea about ASM backup.
using md_backup command, we able to take ASM metadata backup of allias, dg disks, tempalate
If ASM storage got crashed, we adds new ASM storage. how we can recoverer ASM Instance? (Note: we have backup of whole ASM metadata before crashed using md_backup)
is below steps correct?
1. restore ASM metadata using md_restore.
2. restore missing datafiles from RMAN backup.
Kindly suggest. also kindly share good document of ASM if any.
Yes, first start ASM instance then restore metadata (means recreate all the diskgroups) and then finally restore all database files.
If you want more details about ASM please refer Oracle Documentation and McGraw.Hill.Oracle.Automatic.Storage.Management.Nov.2007