VirtualboxCommunication

Communication between two virtual machine

• Check the host name and ip address of second virtual machine

• Communicate between two virtual machine using ssh command with host name and ip address

Import Export and backup of Virtual Machine

• Create backup using export option from file menu

• Export Virtual appliance and provide a path

Linux File System Command

• using df -Th command to check file system disk space usage , show the amount of free disk space in linux

• fsck (file system consistency check) is used to check and optionally repair Linux file systems. .

• lsblk displays block devices, when used with the -f option, it prints file system type on partitions as well:

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• mount command is used to mount a file system in Linux, it can also be used to mount an ISO image, mount remote Linux filesystem and so much more.

• blkid command is used to find or print block device properties, simply specify the disk partition as an argument like so

• file command identifies file type, the -s flag enables reading of block or character files and -L enables following of symlinks:

• The /etc/fstab is a static file system info (such as mount point, file system type, mount options etc) file:

Huge Page Command

• command to check current huge pages details.This huge page size can be increased from 2MB to max 1GB.

Swap Space Command

• Type the following cat command to see total and used swap size:

• another way using grep command

• swapson -s command to show swap usage summary by device

• Use free command to monitor swap space usage

• See swap size in Linux using vmstat command

GREP COMMAND

• consider a file make using cat command

• The -i option enables to search for a string case insensitively in the given file. It matches the words like “UNIX”, “Unix”, “unix”.

• We can find the number of lines that matches the given string/pattern

• Checking for the whole words in a file.The -w option to grep makes it match only the whole words.

• By default, grep displays the entire line which has the matched string. We can make the grep to display only the matched string by using the -o option.

• display the lines that are not matched with the specified search string pattern using the -v option.

• Replacement of new word with old word using sed command