Drop ASM instance.

Question

Hi,
My OCR got corrupted and I am not able to recover as I don't have backup of that. Because of this, CRS daemon is not coming up and this leads me to clean up this cluster and build it again. I am not much worried as this is my second development env.
I want to drop the disk groups but I am not able to do because those are not being mounted.
SQL> select name from v$asm_diskgroup;
NAME
DG1
RECOVERYDEST
SQL> drop diskgroup DG1 including contents;
drop diskgroup DG1 including contents
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15001: diskgroup "DG1" does not exist or is not mounted
If I do remove ASM using DBCA, will all diskgroups be removed or do I need to perform any cleanup?
Thanks,

Answer 1

Thanks Vishwa,
Here is the output,
$ ps -aef|grep d.bin
oracle 5234 5215 0 18:37 ? 00:00:00 /u01/app/oracle/product/10.2.0/crs_1/bin/evmd.bin
oracle 5330 5329 0 18:37 ? 00:00:00 /u01/app/oracle/product/10.2.0/crs_1/bin/ocssd.bin
oracle 7646 7191 0 18:39 pts/1 00:00:00 grep d.bin
$ crs_stat -t
CRS-0184: Cannot communicate with the CRS daemon.
When I do mount the DG1 diskgroup I am getting below error on all nodes,
SQL> startup
ASM instance started
Total System Global Area 92274688 bytes
Fixed Size 1217884 bytes
Variable Size 65890980 bytes
ASM Cache 25165824 bytes
ORA-15032: not all alterations performed
ORA-15130: diskgroup "DG1" is being dismounted
ORA-15066: offlining disk "DG1_0000" may result in a data loss
SQL> alter diskgroup DG1 mount;
alter diskgroup DG1 mount
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15130: diskgroup "DG1" is being dismounted
ORA-15066: offlining disk "DG1_0000" may result in a data loss
Ashok: As far as I know, OCR stores the information about Oracle clusterware controls and if it is not up then clusterware controls won't come up. My crsd daemon is not comming up (even though If I try manually to bring it up) and this daemon is directly liked up with OCR. Does it mean that if this daemon is not up then it won't allow O/S to access OCR? Even If I try to take backup using ocrconfig -export ..it throws an error.
As I don't have backup of OCR, I need to drop the database and uninstall just Oracle clusterware and re-install and create the database. I want to clean up the disk headers as I want to use those to build diskgroup again, do you guys have any idea, how to do that?
Do let me know if you have different view on this.
Thanks.