Feroz DBA'S Blog

I have seen many people are facing issues/trouble to copy the files from the host machine to virtual box, here are the step how to copy the files/folders, Steps to copy the files using pendrive to virtual box: 1. Copy the required files to the pendrive. 2. After copied, simply disconnect and connect the pendrive again. 3. Go to currently running virtual box, select Devices-----> USB Devices ---> select your pendrive,       once selected it automatically install the pendrive drivers on the hosts to access the pendrive in the      virtual box. 4. go to Virtual box and copy the files. Select  Devices-----> USB Devices ---> select your pendrive  (for me the pendrive (HP v220w [1100])

Issue: You may come across the application users reporting that the database performance is slow, and that pint of time you may need to determine there are any systems resource bottlenecks on the reported database server. Cause:  There may be high memory utilization, high processes, high paging, high disk I/O utilization and CPU utilization Workaround Steps: A single OS command VMSTAT will  result all the above bottlenecks. Output of VMSTAT: Interpret the result of VMSTAT (virtual memory disk): These are the general guidelines to interpret the output:       a. If the wa (wait time for I/O) column is high, then it’s an indication that the storage subsystem is            overloaded and next is to investigate further the cause/source of I/O contention.       b. If b (process Sleeping) is continuously greater than 0, then it indicate the not enough CPU     ...

Issue Listener starts fail with the error   Linux Error: 29: Illegal seek Cause Loopback address is missing from the Linux host file (/etc/hosts) Steps to workaround a. Add loopback address in the /etc/hosts file, if already present and it is disabled, make sure it is         enabled. b.  Restart the listener again after making the changes to /etc/hosts file. Example steps to workaround: First check in to the /etc/hosts file, make sure the loopback address (127.0.0.1) entry is not missing, if not present, add the entry of loopback address and try to restart the listener again. Listener start fail with the error " Linux Error: 29: Illegal seek" check the /etc/hosts file has loopback address is enabled, if not enable it and restart the listener again After enabling the loopback address the listener started successfully