What to do when the Linux system has no extra disk space to hang on to???

Some students will certainly meet me this situation, their computer installed on the virtual machine total disk has been divided, so there is no way to continue to create a new partition.

Then we can use the free space below a partition to create a new partition and format it to mount the new system.

First step: Create a 1G size file

Step two: Create a ext3 file system for the partition with this file

3. Create a mount point for the directory and mount it via the Mount command

At this point, your own partition has been created and has been mounted properly.

Here, by the way, the DD command.

The DD command is also a copy of the file, but it differs from the CP command underlying principle.

CP is by taking the data stream from the underlying hard drive into the in-memory cache and then into the other address of the hard drive

The DD command eliminates the caching of data into memory. Similar will be deposited directly from one place on the hard drive to another place via the data stream.

How to use the DD command

Where if is the input filesystem refers to the data source

And of is the output filesystem refers to the whereabouts of the data

Of course, if the source is followed by a directory, then it will be copied directly from the first byte of the directory,

This principle can be used to copy the MBR.

Backup: DD IF=/DEV/SDA of=/mnt/usb/mbr.backup bs=512 count=1

Restore: DD if=/mnt/usb/mbr.backup OF=/DEV/SDA bs=512 count=1

What to do when the Linux system has no extra disk space to hang on to???