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Ramesh Natarajan

Question: How do I lookup the wwn address of my HBA card installed on the Linux system. I need this information to create zoning on my fiber channel switch. Answer: Use one of the following methods to view the HBA WWN address on Linux. Method 1: /sys/class/scsi_host/host{n}/device/fc_host:host{n}/port_name File On Redhat 5 and above (including OEL [...]

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Question: I would like to add more swap space to my Linux system. Can you explain with clear examples on how to increase the swap space? Answer: You can either use a dedicated hard drive partition to add new swap space, or create a swap file on an existing filesystem and use it as swap [...]

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10 Things Any Monitoring Software Should Do (Nagios Does it)

If you are a system administrator, or IT manager, or someone who is responsible for IT infrastructure, you should implement an enterprise level monitoring solution. The shell script you’ve written that does a ps -ef and sends you an email might do the basic job, but it doesn’t count as monitoring. If you want to [...]

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How to Allow MySQL Client to Connect to Remote MySQL server

By default, MySQL does not allow remote clients to connect to the MySQL database. If you try to connect to a remote MySQL database from your client system, you will get “ERROR 1130: Host is not allowed to connect to this MySQL server” message as shown below. $ mysql -h 192.168.1.8 -u root -p Enter [...]

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RAID 0, RAID 1, RAID 5, RAID 10 Explained with Diagrams

RAID stands for Redundant Array of Inexpensive (Independent) Disks. On most situations you will be using one of the following four levels of RAIDs. RAID 0 RAID 1 RAID 5 RAID 10 (also known as RAID 1+0) This article explains the main difference between these raid levels along with an easy to understand diagram. In [...]

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Question: I have purchased Linux support for RHEL and OEL from Oracle corporation. How do I register my Linux system to Oracle support network to download and update packages? Can you explain me with step-by-step instruction? Answer: After purchasing Linux support from Oracle, you should register your Linux system with Oracle’s Unbreakable Linux Network using [...]

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As part of our on-going VMware series of articles, we earlier discussed about how to install VMware ESXi server, and  how to install vSphere Client. In this article, let us see how to create a new datastore using vSphere client. 1. View Existing ESXi VMware Datastores Launch vSphere Client -> Click on the top node [...]

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Three Sysadmin Rules You Can’t (And Shouldn’t) Break

When I drafted this article, I really came-up with 7 sysadmin habits. But, out of those 7 habits, three really stood out for me. While habits are good, sometimes rules might even be better, especially in the sysadmin world, when handling a production environment. Rule #1: Backup Everything ( and validate the backup regularly ) [...]

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