Linux Skills

In Fedora, the ramdisk is disabled by default, that is, it is compiled into the kernel, but as a module, which will be loaded into the kernel when actually used. So, it is necessary to compile the kernel manually to select the ramdisk as the built-in modules.

In Ubuntu, the ramdisk support is enabled by default, so the steps are easier compared to Fedora.

Using the following commands to list the ramdisk:

The output will be like:

Format the ramdisk as an ext4fs:

Then mount it:

By default, Ubuntu doesn‘t install the ssh server, so the following command will fail:

Using the following command to install the ssh-server:

Then all things will go well.

It is easy to do with real root user:

The CPU status can be checked by:

To re-enable the CPU:

The SELinux has some negative effect on the self-defined filesystem, so it is necessary to disable it, using the following command:

will list the status of the SELinux,

To change the status of SELinux, modify the configure file in:

The easiest way is as follows:

Add the following two lines to the end of the file:

This enables the Chinese characters to be recoginized by the system.

I am working on a project which has something to do with a remote server, and I have to ssh to that server, but the server is Fedora and my os is Ubuntu, and it turns out it takes a long time to resove the host/server IP, the solution to this problem is:

Afer a failed attempt to upgrade the Ubuntu13.10 to Ubuntu 14.04, the system shows a popup window everytime the system boots, the title of the window is "System Program Problem Detected". The following method can be used to solve the problem:

This command will delete the crushed software of the system so that the reporting utility won‘t work, thus eliminating the annoying message.

Recently, a project requires frequently mounting and testing a filesystem, and it is very likely that the newly-mounted filesystem will crash for all kinds of reasons, and after the accident, it is no longer possible to umount the filesystem in a normal way. The error message from the OS is as follows:

With the -l option of umount, the result can be seen as follows: