HowTo: Create sar Graphs With kSar [ Identifying Linux Bottlenecks ]

Posted on in Categories Debian Linux, fedora linux, File system, Hardware, High performance computing, Howto, Linux, Linux Scalability, Monitoring, Networking last updated December 15, 2009

The sar command collect, report, or save UNIX / Linux system activity information. It will save selected counters in the operating system to the /var/log/sa/sadd file. From the collected data, you get lots of information about your server:

  1. CPU utilization
  2. Memory paging and its utilization
  3. Network I/O, and transfer statistics
  4. Process creation activity
  5. All block devices activity
  6. Interrupts/sec etc.

sar output can be used for identifying server bottlenecks. However, analyzing information provided by sar can be difficult, so use kSar, which can take sar output and plot a nice easy to understand graph over period of time.

BIND Named: Set a Zone Transfer IP Address For Master DNS Server

Posted on in Categories BIND Dns, CentOS, data center, fedora linux, FreeBSD, High performance computing, Linux Scalability, RedHat/Fedora Linux, Troubleshooting last updated January 8, 2009

I’ve three nameserver load-balanced (LB) in three geo locations. Each LB has a front end public IP address and two backend IP address (one for BIND and another for zone transfer) are assigned to actual bind 9 server running Linux. So when a zone transfer initiates from slave server, all I get errors. A connection cannot be established, it tries again with the servers main ip or LB2 / LB3 ip. This is a problem because my servers are geo located and load balanced. However, there is a small workaround for this problem.

Top 10 Linux Virtualization Software

Posted on in Categories Linux, Linux desktop, Linux distribution, Linux Scalability, Linux Virtualization, Networking, RedHat/Fedora Linux, Security, Solaris, Storage, Ubuntu Linux, UNIX, vmware, Windows server, xen last updated December 6, 2009

Virtualization is the latest buzz word. You may wonder computers are getting cheaper every day, why should I care and why should I use virtualization? Virtualization is a broad term that refers to the abstraction of computer resources such as:

  1. Platform Virtualization
  2. Resource Virtualization
  3. Storage Virtualization
  4. Network Virtualization
  5. Desktop Virtualization

This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.

Linux: Boot a 2TB+ partition or Larger Array Using Grub

Posted on in Categories CentOS, data center, fedora linux, File system, Gentoo Linux, Hardware, High performance computing, Howto, kernel, Linux, Linux Scalability, Linux Virtualization, RedHat/Fedora Linux, Storage, Tips, vmware, xen last updated December 6, 2008

I’ve already written about creating a partition size larger than 2TB under Linux using GNU parted command with GPT. In this tutorial, I will provide instructions for booting to a flat 2TB or larger RAID array under Linux using the GRUB boot loader.

mount forcedirectio: Disable Linux CIFS / NFS Client Caching

Posted on in Categories CentOS, File system, GNU/Open source, kernel, Linux, Linux Scalability, RedHat/Fedora Linux, Storage, UNIX last updated November 16, 2008

If your network is heavily loaded you may see some problem with Common Internet File System (CIFS) and NFS under Linux. By default Linux CIFS mount command will try to cache files open by the client. You can use mount option forcedirectio when mounting the CIFS filesystem to disable caching on the CIFS client. This is tested with NETAPP and other storage devices and Novell, CentOS, UNIX and Red Hat Linux systems. This is the only way to avoid data mis-compare and problems.