Hi guys,
A few hours ago, I installed Oracle 11g R2 with ASM on Oracle Linux 6, 64bit in my VirtualBox.
While installing database on DBCA, I got an error.

Several warning windows raised up. and I pressed OK, and completed installation.
And after rebooting my virtual machine, I put a command to start whole database (technically speaking, standalone server). But I can not start database because of the following errors.
[oracle@localhost ~]$ srvctl start database -d orcl
PRCR-1079 : Failed to start resource ora.orcl.db
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0
ORA-01078: failure in processing system parameters
CRS-2674: Start of 'ora.orcl.db' on 'localhost' failed
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0
What should I do for solving this problem ???