Cluster SSH tool Utility

Many times you come across scenario’s when you wish to open multiple ssh windows and execute same commands.e.g You wish to see alert log for multi-node RAC simultaneously or edit sysctl.conf files for multiple machines. Cluster SSH utility helps solve this problem as it opens multiple SSH sessions and allows simultaneous control. In case you are…

Effect Of Multiple SHMMAX Settings

Last week I saw a warning message at database startup time saying: WARNING: EINVAL creating segment of size 0x000000000f0020xx fix shm parameters in /etc/system or equivalent It is an Oracle 10204 database running on Solaris. Searching MOS for exact meaning for this warning, it states that a new shared memory segment is getting created to…

How To Discover Disk Name When LUN Number is Known (OEL5)

I am creating 11gR2 RAC setup for one of my client. Following Oracle documentation for storage, I opted for Oracle ASM and asked storage team for new physical devices. Storage admin thus provided me with a set of LUNs instead of actual physical device names like /dev/sdcxxx. Now the major task is to get the…

Sqlplus connection on AIX taking too long

Recently we faced a performance issue, where in sqlplus connection from application server A (AIX 5.3) to Database server DB (different physical server,10gR2 on AIX 5.3) was taking nearly 1-2 minutes.  We did some quick check’s to narrow down the problematic area.i.e Is it network or database server or some issue with application server? 1)Vmstat…

Use awk/sed in vi

Thought of sharing some useful info which can help you to do your work faster in vi.You can use awk/sed scripts in vi using following command in vi :%!scriptname Here the scriptname file should have execute privilges for user. I used this to create a useful script which I was doing by typing multiple substitution…

Connections to DataBase Hang Including “/ as sysdba”

Recently I faced one issue where all the connection to database hung and it was also not possible to login to database using “/ as sysdba”. To get access of sqlplus I used the following syntax: $ sqlplus -prelim / as sysdba With “prelim” option we can run some commands which will help in collection…