RSSCategory: LINUX HOWTO

Linux Scan for New Scsi Device to Detect New Lun Without Reboot

This will scan the scsi host and there is no need to reboot to make devices (luns) visible. echo "- - -" > /sys/class/scsi_host/host#/scan Verify fdisk -l tail -f /var/log/message Replace host# with actual value such as host0. You can find scsi_host value using the following command: # ls /sys/class/scsi_host Now, type the following to […]

March 20, 2011 | By
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Linux Install Network Or Ethernet Card In Linux

How to install a Network card in linux. There are different ways of installing a network card in linux- and that too depending on the linux distribution that you are using. I will explain each one of these methods here. 1) The Manual method First open the computer case and insert the network card into […]

March 20, 2011 | By
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How To Use Linux Kill Command

The word kill itself shows its clear meaning and purpose. In Linux, kill command is used for terminating the process. The command kill sends the specified signal to the specified process or the process group. First we need find PID of the process, so that we can terminate the process. In our example, we will […]

March 20, 2011 | By
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CPU Bottleneck - How To Use Vmstat, Mpstat and SAR Commands

One of the main functions the kernel or Operating System is Memory Management. When process try to access physical memory, if physical memory not free, than kernel move the inactive processes to virtual memory then it is called Paging. To know which process is using physical memory and virtual memory, we use vmstat, mpstat, sar commands. […]

March 14, 2011 | By
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6 Commands to Monitor CPU Usage in Linux

CPU is core part the system and processes all the task. There are many methods to check the CPU performance on linux system. Most commonly used commands are top, ps, sar, iostat, mpstat and to check the daily CPU performance. Whenever CPU is busy in processing a particular task, it becomes unavailable to other processes. […]

March 14, 2011 | By
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How To Find Un Allocated Space On Linux

Using only fdisk, the "start" and "end" columns in your 'fdisk -l' output are the start and end cylinders. From the header of your 'fdisk -l' output, you can also see how many cylinders the disk has and how many bytes a cylinder represents. fdisk -l /dev/cciss/c0d0 Disk /dev/cciss/c0d0: 72.8 GB, 72833679360 bytes 255 heads, […]

March 9, 2011 | By
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Linux Samba Share Accessing And Mounting

Samba is a service in Linux that provides seamless file and print service to SMB/CIFS clients. One of the main feature of samba is that it allows interoperability between Linux/Unix servers and Window-based clients. In general, you can share resource-like files and printers over network between Unix to Unix as well as Unix to Windows. In […]

March 9, 2011 | By
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Create, Format, Mount Filesystems in Linux

A filesystem is an organization of data and metadata on storage device. You can also say it as organizing data in systematic manner. Linux filesystem interface is implemented as a layer architecture. Today unix-like operating system contains only files. If you want to access any files in unix-like OS, filesystem has to be mounted where […]

February 25, 2011 | By
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Shared Memory Settings In Linux With Examples

Shared memory is the memory that may be accessed by multiple processes; i.e. a memory region that can be shared between different processes and a better way of passing data between two processes. Shared memory is the fastest form of Inter Process Communication which is currently available. Assume that the program will create a memory […]

February 25, 2011 | By
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In Linux How To Flush Routing Table From Cache

Static routes are much important if you have more than one interface connecting to different subnet. Enabling static routes gains much performance for your network. Either of the two below commands can be used to set/delete static routes. 1) ip route 2) route This page I am not referring about how to add/delete static route […]

February 25, 2011 | By
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How To Create, Extend, Remove Swap Partition in Redhat/Centos LVM

Swap memory is required when the system requires more memory than it is physically available. The kernel swaps out less used pages and gives memory to the current process that needs the memory immediately. So a page of memory is copied to the pre-configured space on the hard disk. Disk speed is much slower compared to […]

February 25, 2011 | By in FILE SYSTEM,LINUX HOWTO
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Show Storage Luns Allocated on Linux

Hope this output helps you to trace something that you are looking for. I have pasted some of the Storage LUNs related to the output from my RHEL 5 Server. Below scsi file shows all the visible LUNs that are identified through each NIC/HBA card. This server had two Qlogic HBA card so that LUNs […]

February 25, 2011 | By
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Linux XDMCP Service - How to access remote Linux GUI

Most linux admins work from shell and there is not much requirement to connect to the X window. But, in some cases, we need to access graphic console (X window Manager). For example, if a user needs to install oracle and he/she might need access to linux remote GUI; then I personally recommend to disable […]

February 25, 2011 | By
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How To Backup LVM Configuration On Linux (vgcfgbackup & vgcfgrestore)

Due to several reason a volume group may become corrupted after unintended user intervention. LVM will not be aware of this situation unless the alternate is already on the volume group, and may allow to add the alternate path to a different volume group. Two of the useful commands provided as part of LVM are vgcfgbackup and vgcfgrestore. […]

February 25, 2011 | By
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