A rough utilization of Linux cat command would be to make a full disk backup or a disk partition backup or cloning of a disk partition by redirecting the command output against the partition of a hard disk, or USB stick or a local image file or write the output to a network socket.
In the below example the first partition on the first hard disk, which corresponds to the /boot partition i.e. /dev/sda1, is cloned onto the first partition of the second disk (i.e. /dev/sdb1) using the Linux redirection operator.
# cat /dev/sda1 > /dev/sdb1
After the command finishes, the cloned partition is mounted to /mnt and both mount points directories are listed to check if any files are missing.
# mount /dev/sdb1 /mnt # ls /mnt # ls /boot
In order to extend the partition file system to the maximum size issue the following command with root privileges.
$ sudo resize2fs /dev/sdb1
The cat command is an excellent tool to manipulate text files in Linux and some special multimedia files, but should be avoided for binary data files or concatenate shebang files. For all other options don’t hesitate to execute man cat from console.
$ man cat