ORACLE DBA BLOG

 Extract region of AWS stream from EC2 Instance .  [hostanme]~#aws configure list       Name                    Value             Type    Location       ----                    -----             ----    --------    profile                <not set>             None    None access_key     ********************         iam-role secret_key     ********************         iam-role     region           ap-northeast-1             imds      [hostanme]~# aws configure list|grep region|awk '{print $2}' ap-northeast-1 export AWSREGION=` aws configure list|grep region|awk '{print $2}'` echo $AWSREGION

To extract Oracle Home location from /etc/oratab : #export ORACLE_HOME=`cat /etc/oratab|grep -v "^#"|cut -d: -f2 -s | grep db | head -1`  => If all DB are of same version #export ORACLE_HOME=`cat /etc/oratab|grep -v "^#"| grep $db|cut -d: -f2 -s | head -1` => If Server has Different Versions of DB and get home Details using SID    ###################find SID's in Servers############# ps -ef | grep "ora_smon"|grep -v grep|awk '{print $8}'|awk -F_ '{print$3}' ps -ef|grep "ora_smon"|awk -F_ '{print$3}'|tail -1 ps -ef|grep "ora_smon"|awk -F '_' '{print$3}'|tail -1   ps -ef|grep smon|egrep -i -v '19|ASM|grep'|awk -F_ '{print $3}' #################list Oracle HOme####################  grep "^$ORACLE_SID:" /etc/oratab|awk -F: '{print$2}' ##############List Oracle Version#####################  grep -i "^$ORACLE_SID:" /etc/oratab | awk -F/ '{print$6

Check active version and Software Version of  Cluster in Pre Upgrade Environment .    crsctl query crs activeversion crsctl query crs softwareversion PRECHECKS :

HugePages is a feature integrated into the Linux kernel from Release 2.6 that allows large SGA memory to be utilized with reduced overhead by ensuring that the memory is not paged to disk. HugePages allows you to use much larger page sizes (for example, 2MB or 4MB) than the default 4K page size, which can be crucial for faster Oracle database performance on Linux, and increasingly so for systems with large RAM and database SGA sizes, as is the case even for small CC deployments.   HugePages results in smaller page tables and less CPU time spent on memory management, increasing the performance of large database instances   One possible drawback of using HugePages is that you cannot use it in conjunction with Automatic Memory Management (AMM); you must use Automatic Shared Memory Management (ASMM) instead. Therefore, before you decide to implement HugePages, you may want to weigh its advantages against any disadvantages of not being able to enable AMM. Witho