lvm logical volume and disk quota

lvm Logical Volume

Partition advantages:

• Optimize read and write performance
• Implement disk space quota limits
• Increase repair speed
• Isolate systems and programs
• Installing multiple OS
• Using a different file system

Disadvantages of partitioning:

• Only use one hard drive space
• If the partition must be contiguous space
• If the size of the partition cannot be changed (you cannot change the size at will, deleting the partition will result in data loss)

Do not install graphics at work: in order to reduce hardware resource consumption.

What is a logical volume

Split (logically split) the hard disk or partition into the smallest unit PE, and then form a logical volume (**one PE: 4M**)

Create logical volume

1. Have a physical disk: physical volume (partition can be a whole hard disk)
2. Combines multiple physical volumes, and the capacity of the volume group is extracted from the physical volumes
3. The capacity of creating a logical volume is extracted from the volume group

/dev/sdc represents the entire hard disk
/dev/sdc1 represents a partition

Note: Use the partition as the physical volume, the partition must be in 8e format

1. Create a physical volume
[[email protected] ~]#pvcreate /dev/sdb

2.
[[email protected] ~]#vgcreate vg0 /dev/sdb

3.
[[email protected] ~]#lvcreate -L +15G -n ky22 vg0

4.
The logical volume was created successfully, butStill unable to use
to create a file system, mount

[[email protected] ~]#mount /dev/vg0/ky22 /mnt

How to expand:

The first case: the original volume group has enough space

The second case: The original volume group does not have enough space
1. The volume group must be expanded first
2, and then the logical volume should be expanded

xfs file format

Extend volume group

[email protected] ~]#vgextend vg0/dev/sdc

Extend Logical Volume

[[email protected] ~]#lvextend-L +10G /dev/vg0/ky22
[[email protected] ~]#xfs_growfs /mnt

or
[[email protected] ~]#lvextend -r -L +2G /dev/vg0/ky22 (ext4 file system can also be used)

Disk Quota

Disk Quota Function:
Disk quota can limit the disk space that can be used by a specified account, which can prevent other users from being unable to work normally or even affect the system operation due to excessive use of disk space by one user.
This feature is very important in server management, but not so meaningful for stand-alone users.

• Function: Improve system security
• Definition: Used disk space for quota limit
• File system: NTFS