My first thought was to create a 2nd (or multiple) ASM instances on the same node which manage seperated DGs. This is quite easily possible: Just create a spfile for the 2nd ASM, just make sure to add *.DB_UNIQUE_NAME
So I could create different DGs in different ASM-instances.
But now the troubles starts: In my test-RDBMS I could only see the DGs of the first ASM.
So I created a SR(7275580.994) at MetaLink to ask how to do it and wether or not it's supported in single instance or RAC.
To summarize the answers:
- It is possible to run multiple ASMs on a node
- One RDBMS can onlybe served by one ASM
- all the GUIs are not aware of multiple ASMs
- it's not supported in RAC
I have 2 ASMs: +ASM (default) and +ASM2 (2nd, with changed DB_UNIQUE_NAME and ASM_DISKSTRING) and one RDBMS. DG ASM1_DG created in +ASM, DG ASM2_DG created in +ASM2.
- Test 1
=> only ASM1_DG1 visible in RDBMS .
- Test 2
=> ASM2_DG1 visible
! create tablespace in ASM2_DG1
- Test 3
- restart RDBMS
=> only ASM2_DG1 visible in RDBMS
- Test 4
=> DBCA only shows ASM1_DG1:
- Test 5
- shutdown +ASM
- switch ASM1_DG to +ASM2 (some fiddling with ASM_DISKSTRING and symlinks)
- mount ASM1_DG in +ASM2
- create TS in ASM1_DG
- shutdown RDBMS and +ASM2
- switch ASM1_DG back to +ASM
- startup +ASM, +ASM2 and rdbms
- this constelation (ASM1_DG mounted on +ASM, ASM2_DG mounted on +ASM2) led to this error-message:
ORA-01157: cannot identify/lock data file 8 - see DBWR trace file ORA-01110: data file 8: '+ASM1_DG/berx2/datafile/asm1_dg.256.676065339' ORA-17503: ksfdopn:2 Failed to open file +ASM1_DG/berx2/datafile/asm1_dg.256.67 6065339 ORA-15001: diskgroup "ASM1_DG" does not exist or is not mounted ORA-15001: diskgroup "ASM1_DG" does not exist or is not mounted
Within the SR Bug:6991236 was mentioned.
This Bug is not visible right now, but interpreting the header I can guess it's an enhancement request to allow or support multiple ASM-instances with differen OS-users in a cluster-environment. It's shown to be fixed (implemented) in 11gR2 and has status 98 (Suggestion Implemented). We will see when 11gR2 is out.