acfsutil size: ACFS-03008: The volume could not be resized.

Error:

$ /sbin/acfsutil size +100G /datapump
acfsutil size: ACFS-03008: The volume could not be resized.  Either the volume expansion's limit has been reached or ASM could not expand the storage.

Cause:
acfs volume can only be resize 5 times

Solution:

1.  /bin/umount -t acfs /datapump
2.  /sbin/fsck -a -v -y -t acfs /dev/asm/datapumpvol-23
3.  /bin/mount -t acfs /dev/asm/datapumpvol-23 /datapump

Verify ASMLIB configuration

Usually System Admin will install ASMLIB and create ASM disks Here are a few useful command to verify ASMLIB was configured properly

1 Verfiy rpm installation

rpm -qa|grep oracleasm


2. ASM mount point creation

df -ha|grep oracleasm
oracleasmfs              0     0     0   -  /dev/oracleasm

3 Query and liks ASM disk
/etc/init.d/oracleasm listdisks
/etc/init.d/oracleasm querydisk  


4. Discover asm disks using string 'ORCL:*'

/usr/sbin/oracleasm-discover 'ORCL:*' 

5. Simulate the disk discovery from the operating system level, using tool kfod.  ($ORACLE_HOME/bin). 

$ORACLE_HOME/bin/kfod asm_diskstring='ORCL:*' disks=all

ORA-29701 On Reboot for Non-RAC database Uses ASM

ORA-29701: unable to connect to Cluster Manager

On Server Reboot, Oracle CSS daemon doesn't start in time, then the Automatic Storage
Management (+ASM) instance can't start and therefore all instances are unable to start. 

Solution (according to Note:264235.1)

put the entry in 'inittab' file about the init.cssd script before
running the runlevel 3

example of inittab:

(...)
s2:23:wait:/sbin/rc2 >/dev/msglog 2<>/dev/msglog 
s3:3:wait:/sbin/rc3 >/dev/msglog 2<>/dev/msglog 
s5:5:wait:/sbin/rc5 >/dev/msglog 2<>/dev/msglog 
(...)
h1:3:respawn:/etc/init.d/init.cssd run >/dev/null 2>&1 


you need to change it in this way:


(...)
s2:23:wait:/sbin/rc2 >/dev/msglog 2<>/dev/msglog 
h1:3:respawn:/etc/init.d/init.cssd run >/dev/null 2>&1 
s3:3:wait:/sbin/rc3 >/dev/msglog 2<>/dev/msglog 
s5:5:wait:/sbin/rc5 >/dev/msglog 2<>/dev/msglog 
(...)

Flashback primary database in a dataguard environment

Following steps have been tested in Oracle 10.2

1, On primary database, Stop dataguard broker.
>alter system set dg_broker_start = false;

2, Flashback database to SCN
>shutdown immediate;
>startup mount;
>flashback database to SCN ;
>alter database open resetlog;
>alter system set dg_broker_start = true;


3, Determine the SCN before the RESETLOGS operation occurred.
> SELECT TO_CHAR(RESETLOGS_CHANGE# - 2) FROM V$DATABASE; --should be same as 

4, Obtain the current SCN on the standby database.
>SELECT TO_CHAR(CURRENT_SCN) FROM V$DATABASE;


5, Determine if it is necessary to flash back the standby database.

If the value of CURRENT_SCN is larger than the value of resetlogs_change# - 2(), issue the following statement to flash back the standby database.
>FLASHBACK STANDBY DATABASE TO SCN resetlogs_change# -2;

•If the value of CURRENT_SCN is less than the value of the resetlogs_change# - 2, skip to Step 6.


6, Restart Redo Apply.

>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;

Remove listener in RAC environment

in 11g
SRVCTL remove listener ...
in 10g
There is no srvctl remove listener command in 10g
Using Netca to remove listener.

Understand Oracle Table Lock (TM)

 

Summary of Table Locks

SQL Statement	Table Lock Mode	RS	RX	S	SRX	X
SELECT...FROM table...	none	Y	Y	Y	Y	Y
INSERT INTO table ...	RX	Y	Y	N	N	N
UPDATE table ...	RX	Y*	Y*	N	N	N
DELETE FROM table ...	RX	Y*	Y*	N	N	N
SELECT ... FROM table FOR UPDATE OF ...	RX	Y*	Y*	N	N	N
LOCK TABLE table IN ROW SHARE MODE	RS	Y	Y	Y	Y	N
LOCK TABLE table IN ROW EXCLUSIVE MODE	RX	Y	Y	N	N	N
LOCK TABLE table IN SHARE MODE	S	Y	N	Y	N	N
LOCK TABLE table IN SHARE ROW EXCLUSIVE MODE	SRX	Y	N	N	N	N
LOCK TABLE table IN EXCLUSIVE MODE	X	N	N	N	N	N

RS: row share
RX: row exclusive
S: share
SRX: share row exclusive
X: exclusive