linux - fdisk-l has a large space, df -h has a small space

Question

My system is Ubuntu 14.04 LTS

Enter the command df -h, the display will be as follows:

Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/ubuntu--vg-root   19G   18G     0 100% /
none                         4.0K     0  4.0K   0% /sys/fs/cgroup
udev                         3.9G   12K  3.9G   1% /dev
tmpfs                        799M  2.0M  797M   1% /run
none                         5.0M     0  5.0M   0% /run/lock
none                         3.9G  4.9M  3.9G   1% /run/shm
none                         100M     0  100M   0% /run/user
/dev/vda1                    236M   37M  188M  17% /boot

The total space is only more than 20 G, which is no longer enough.

And enter fdisk -l, the display will be as follows:

Disk /dev/vda: 322.1 GB, 322122547200 bytes
16 heads, 63 sectors/track, 624152 cylinders, total 629145600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0009d617

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *        2048      499711      248832   83  Linux
/dev/vda2          501758    41940991    20719617    5  Extended
/dev/vda5          503806    41940991    20718593   8e  Linux LVM

Disk /dev/mapper/ubuntu--vg-root: 20.1 GB, 20124270592 bytes
255 heads, 63 sectors/track, 2446 cylinders, total 39305216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/ubuntu--vg-root doesn't contain a valid partition table

Disk /dev/mapper/ubuntu--vg-swap_1: 1069 MB, 1069547520 bytes
255 heads, 63 sectors/track, 130 cylinders, total 2088960 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/ubuntu--vg-swap_1 doesn't contain a valid partition table

Could you please explain it and tell me how to expand the space to the 300G size displayed by fdisk?

Answer 1

Your machine has two hard drives, one is /dev/mapper/ubuntu--vg-root, and the size is 20.1 GB. This is your system disk, and the usage rate has now reached 100%.
The other disk is /dev/vda, which is 322.1 GB in size and is currently unmounted.

Answer 2

Ni’s /dev/vda is not mounted

Answer 3

Current situation: You have a 300G hard disk with two partitions, one is the main partition /dev/vda1, more than 200M, mounted to /boot, an extended partition /dev/vda2, which has a logical partition /dev /vda5, occupies 20G of space. LVM was created on /dev/vda5. LVM allocated 19G of it to /dev/mapper/ubuntu--vg-root and mounted it to the root directory, while the other 1G was allocated to / dev/mapper/ubuntu--vg-swap_1 swap partition.

Problem: Only 20G of the 300G space is used, and the other 280G is not used.

Solution: Use fdisk to create a new partition on the remaining space, then add the newly created partition to LVM, and finally expand the size of /dev/mapper/ubuntu--vg-root. I don’t know the specific command. Familiar, the general idea should be like this.