Review ASM on 11G

ASM on 11G support:- 140 Peta Byte (PB) in External Redundancy (no ASM mirroring)
- 42PB in Normal Redundancy (2-way ASM mirroring)
- 15PB in High Redundancy (3-way ASM mirroring)
- 40 ExaByte of Storage
- 4PB for each ASM disk
- 1 million file per disk group
- 10.000 ASM disks
- 63 disk groups per ASM instance
Oracle database limited file size to 128TB with big file tablespaces and 32k block size.

ASM on Oracle 11G, We'll find new feature on asmcmd command-line

ASMCMD cp
ASM disk group -> OS file system
OS file system -> ASM disk group
ASM disk group -> another ASM disk group on the same server
ASM disk group -> ASM disk group on a remote server

Example:
ASMCMD> cp spfiletestdb.ora /tmp/spfile-backup.ora
source +DATA/TESTDB/spfiletestdb.ora
target /tmp/spfile-backup.ora
copying file(s)...
file, /tmp/spfile-backup.ora, copy committed.

ASMCMD disk group metadata backup and restore
ASM disk group metadata backup and restore functionality.

ASMCMD lsdsk
lists ASM disk information
Example:
ASMCMD> lsdsk
Path
/dev/raw/raw1
/dev/raw/raw2
/dev/raw/raw3
/dev/raw/raw4

SYSASM role
performing ASM administration task.
SQL> connect / as sysasm
Example:
SQL> create user asmadmin identified by password ;
User created.
SQL> grant sysasm to asmadmin;
Grant succeeded.
SQL> conn asmadmin

Enter password:
ERROR:
ORA-15000: command disallowed by current instance type
Warning: You are no longer connected to ORACLE.

SQL> conn asmadmin as sysasm

Enter password:
Connected.

SQL> drop user asmadmin;
User dropped.

SQL> conn asmadmin as sysasm

Enter password:
ERROR:
ORA-01017: invalid username/password; logon denied
Warning: You are no longer connected to ORACLE.
SQL>