ORA-15001: diskgroup does not exist or is not mounted

If you are having role separation for Grid Infrastructure (RAC or standalone) and Database software, you would need to have an OS user (normally named “grid”) for Grid Infrastructure installation and management, and an OS user (normally names “oracle”) for database software installation and management.

Problem Description and receiving ORA-15001

After installing Grid Infrastructure, ASM diskgroups are created as “sysasm” user so that database could be stored on this diskgroup, but then you realize that “oracle” user is not able to access this diskgroup (you may receive ORA-15001 error). Most of the time the reason of this problem is that “oracle” user is not member of OS group “asmdba”. If you are facing this problem, double check whether “oracle” user is member of asmdba OS group or not. While logged in as oracle user, execute “id” command to check this.

[oracle@XXXXXXX1 ~]$ id

uid=54321(oracle) gid=54321(oinstall) groups=54321(oinstall),54322(dba),54323(oper)

Solution
While logged in as “root”, make oracle user member of asmdba OS group.[root@XXXXXXX ~]#  usermod  -g oinstall -G dba,oper,asmdba oracle

Again log in as “oracle” and execute “id” again.
[oracle@XXXXXXX1 ~]$ id

uid=54321(oracle) gid=54321(oinstall) groups=54321(oinstall),54322(dba),54323(oper) ,54325(asmdba)