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:
- CPU utilization
- Memory paging and its utilization
- Network I/O, and transfer statistics
- Process creation activity
- All block devices activity
- 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.
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.
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:
- Platform Virtualization
- Resource Virtualization
- Storage Virtualization
- Network Virtualization
- Desktop Virtualization
This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.
A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. A SSD emulates a hard disk drive interface, thus easily replacing it in most applications. An SSD using SRAM or DRAM (instead of flash memory) is often called a RAM-drive.
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.
The Sun Netra brand has been used for a variety of server computers from Sun Microsystems. These servers used for various purposes such as telecommunications applications.
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.