How does time stamp calculated in linux
In Linux OS time stamps are printed in \"seconds since boot\". The system uptime can be helpful to calculate an absolute time stamp if needed (run the uptime command).
The algorithm below is demonstrated on the example given above:
[196149.728085] wlan0: authenticated
Take the logs time stamp in seconds:
Error - resize2fs Operation not permitted
Error - resize2fs: Operation not permitted While trying to add group
Extending LVM partition and resize it
# lvextend -L+1G /dev/VGw3/calc
# resize2fs /dev/VGw3/calc
Today while resizing the LVM I was receiving the below error message.
resize2fs: Operation not permitted While trying to add group #1234
The fix is to remove and recreate the journal. If ..
How to find NFS version on linux host
How do you find NFS version on a UNIX or Linux host?
The NFS service will be listed in the fourth column titled service. The NFS version will be listed in the second column.
To find the NFS version bellow commands can be used
# rpcinfo -p | grep nfs
Hotplug Add remove memory online
How to use memory hotplug?
First make sure that your linux kernel is configured or compiled with hotplug memory support, Once the server is with new linux kernel, new memory hotplug command will be available.
Hotplug Add memory
# echo \"(physical memory address)\" > /sys/devices/system/memory/probe
This command is to identify new memory. If ..
HP Array Diagnostic Report - ADU Report
HP ADU report is quite simple and easy in Linux Operating System. ADU CLI is distributed using Red Hat Package Manager (RPM) packages
To start the application:
If /usr/sbin is already added in your path, just type:
# hpaducli -f adu-report.zip
# /usr/sbin/hpaducli -f adu-report.zip
More options can be found by \"hpaducli -help\" ..
Search for a particular word in all files
Today I had a requirement to search for a string in all the files which has particular word or text. You can find or search for the string in linux machine as below.
To find the string in all directories
# find / -name \"*.*\" | xargs grep -i \'find string\'
Reload file without server reboot
Today I came across a situation to edit the user profile on my linux dev machine. I have added few alias in my server into file /etc/profile. Now I have a requirement like I want my changes has to get effect without server reboot.
Most of us would know about sysctl ..
Accessing multiple files in vi editor
If you are using gnome vim enhanced version supports gui version. But normally as a sever admin we work in terminal.
Open multiple files in a terminal using below command
# vi file1 file2 file3
Now from the above command vim/vi editor opens file1 on the terminal
You can switch over the ..
Find SAN port name in linux
Check fiber channel exist in server or not
# lspci | grep -i fibre
00:00.1 Fibre Channel: ServerEngines Corp. Emulex OneConnect 10Gb FCoE Initiator
# find /sys -type d -name fc_host
Check the Port number by using find command
# find $(find ..
Set user defined extension in tomcat
Set user defined extensions in Tomcat,
Just do URL mapping in web.xml as explained below,
How to install skype on linux
When you try to install skype using yum, you might get warnings/error or message as dependencies missing.
For this you must know that skype is a 32 bit application. That means u need some 32 bit libs required for this setup, In this quick tip i will show you ..
Command+C = Copy
Command+V = Paste
Command+X = Cut
Command+A = Select All
Command+Shift 3 = Capture the screen to a file
Command Ctrl Shift 3 = Capture the screen to the clipboard
Command+Shift 4 = Select an area to be captured to a file
Avoid multiple spider bad bots
This helps to avoid serverload because of badbots. For me normally if u have build a good dynamic sitemap then you can allow other spider or bots to crawl your entire site. But if is not then there will be issues like server load spike, wastage of Bandwidth etc.
To block ..
Boot android mobile in safe mode
You can easily boot your android phone by following the below steps,
1. Hold down the power button in your phone until the option menu comes out on the screen.
2. Then, long press the Power Off option and you will obtain a message on the screen to verify whether ..
Find which process use more system resource
The below commands can be used to calculate system resource used by server. You can find which commandline is using more CPU resource. But ofcourse you can calculate the system resource by using top command, but still below are the below commands or other methods which can be used to ..