Creating and Mounting a File System

Scenarios

After the logical volume is created, you need to create a file system on the logical volume and mount the file system on the corresponding directory. This section shows how to create an ext4 file system on a logical volume and mount the file system on /Data1.

Procedure

Create a file system.

mkfs.<file-system-format> <logical-volume-path>

Example command:

mkfs.ext4 /dev/vgdata/lvdata1

Information similar to the following is displayed:

[root@ecs-lvmtest ~]# mkfs.ext4 /dev/vgdata/lvdata1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
983040 inodes, 3932160 blocks
196608 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2151677952
120 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Create a mount point.

mkdir <mount-point>

Example command:

mkdir /Data1
Mount the file system on the mount point.

mount <logical-volume-path> <mount-point>

Example command:

mount /dev/vgdata/lvdata1 /Data1
Query the file system mount information.

mount | grep <mount-point>

Example command:

mount | grep /Data1

Information similar to the following is displayed:
```
[root@ecs-lvmtest ~]# mount | grep /Data1
/dev/mapper/vgdata-lvdata1 on /Data1 type ext4 (rw,relatime,data=ordered)
```
In the command output, dev/mapper/vgdata-lvdata1 indicates the file system path. Take note of this path, which will be used in 6.
Perform the following operations to enable auto mount of the file system at the system start:
If it is not configured, you need to manually mount the file system every time the ECS is restarted.
1. Query the file system UUID.
  blkid <file-system-path>
  
  In this example, the UUID of dev/mapper/vgdata-lvdata1 is queried.
  
  blkid /dev/mapper/vgdata-lvdata1
  
  Information similar to the following is displayed:
```
[root@ecs-lvmtest ~]# blkid /dev/mapper/vgdata-lvdata1
/dev/mapper/vgdata-lvdata1: UUID="c6a243ce-5150-41ac-8816-39db54d1a4b8" TYPE="ext4"
```
  In the command output, the UUID is c6a243ce-5150-41ac-8816-39db54d1a4b8.
2. Open the /etc/fstab file.
  vi /etc/fstab
  Information similar to the following is displayed:
```
[root@ecs-lvmtest ~]# vi /etc/fstab

#
# /etc/fstab
# Created by anaconda on Tue Nov  7 14:28:26 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=27f9be47-838b-4155-b20b-e4c5e013cdf3 /                       ext4    defaults        1 1
UUID=2b2000b1-f926-4b6b-ade8-695ee244a901 /boot                   ext4    defaults        1 2
```
3. Press i to enter editing mode.
4. Move the cursor to the end of the file and press Enter. Then add the following information:
```
UUID=c6a243ce-5150-41ac-8816-39db54d1a4b8 /Data1                  ext4    defaults        0 0
```
  The file content is described as follows:
  - Column 1: indicates the UUID. Enter the UUID queried in 1.
  - Column 2: indicates the file system's mounting directory. Enter mounting directory /Data1 created in 3.
  - Column 3: indicates the file system format. Enter file system format ext4 configured in 2.
  - Column 4: indicates the mounting option. In this example, defaults is used.
  - Column 5: indicates the backup option. Enter either 1 (the system automatically backs up the file system) or 0 (does not back up the file system). In this example, 0 is used.
  - Column 6: indicates the scanning option. Enter either 1 (the system automatically scans the file system at system start) or 0 (does not scan the file system). In this example, 0 is used.
5. Press Esc, enter :wq!, and press Enter.
  The system saves the modifications and exits the vi editor.
Verify that the file system can be auto-mounted at startup.
1. Unmount the file system.
  umount <logical-volume-path>
  
  Example command:
  
  umount /dev/vgdata/lvdata1
2. Reload all the content in the /etc/fstab file.
  mount -a
3. Query the file system mount information.
  mount | grep <mount-point>
  
  Example command:
  
  mount | grep /Data1
  
  If information similar to the following is displayed, auto mount has taken effect:
```
[root@ecs-lvmtest ~]# mount | grep /Data1
/dev/mapper/vgdata-lvdata1 on /Data1 type ext4 (rw,relatime,data=ordered)
```