LVM logical Volumes
1. Manage the scattered space.
2. Expansion and reduction of logical volume dynamics.
First, a number of physical volumes (PV) are formed into a volume group (VG),
The logical volume (LV) is then divided from the volume group.
Command: Create creation
Extend extension
Vgcreate Volume Group name partition
PVS displays physical volume basic information
VGS Display Volume Group basic information
LVS Display Logical Volume basic information
First, create physical volumes and volume groups
Format: vgcreate volume Group name partition
Example: Vgcreate myvg/dev/sda[1-3]
Creating a volume group physical volume directly can be formed.
Ii. Creating a logical volume
Format: lvcreate-l Logical Volume Size-n Logical volume name of the volume group
Example: Lvcreate-l 16g-n mylv MYVG
Third, use the logical volume LV
Example: MKDIR/LVLV
Vim/etc/fstab
/DEV/MYVG/MYLV/LVLV EXT4 Defaults 0 0
Mount-a
Df-h
Expansion of logical volumes
A logical volume extension that supports on-line operations.
One, the volume group has enough space left.
1. Directly extend the space of the logical volume
Example: VGS
Lvs
Lvextend-l 18G/DEV/MYVG/MYLV
2. Extending the file system
Extended Ext4 File system: RESIZE2FS partition
Extended XFS File system: XFS_GROWFS partition
Example: RESIZE2FS/DEV/MYVG/MYLV
Df-h
Second, the volume group does not have enough space left
1. Expand the volume group first
Format: Vgextend Extended volume Group name partition
Example: Vgextend myvg/dev/sda5
2. Extending the space of a logical volume group
Example: Lvextend-l 25g/dev/myvg/mylv
3. Extended File System size
Example: RESIZE2FS/DEV/MYVG/MYLV
Settings for PE
PE: The unit of volume group partition space, default 4M.
Function: The size of the logical volume can be created more precisely.
To set the size of a PE when creating a volume group
Format: vgcreate-s PE size Volume group name partition
Lvcreate-l PE number-n test Volume group name
Vgchange-s PE Size Volume group name (Modify PE size)
Example: Vgchange-s 2M MYVG
Lvcreate-l 50-n Test MYVG
Managing swap space (equivalent to virtual memory)
When physical memory is insufficient, use disk space to simulate memory.
To some extent, alleviate the problem of insufficient memory.
Swap partition: Swap space acting as an idle partition
Command:
MKSWAP partition Format Swap command
Example: Mkswap/dev/sda6
Swapon-s View Swap command
SWAPON/DEV/SDA6 Enable swap space
SWAPOFF/DEV/SDA7 Deactivate swap Space
SWAPON-A is designed to detect swap mounts
Auto mount on Boot
Example: Vim/etc/fstab
/dev/sda6 swap swap Defautls 0 0
Swapon-a
Swapon-s
LVM logical volume and management swap space for Linux