- lvs
- raid
lvm： logical volumes manager，从物理设备创建虚拟块设备，将一个或多个底层块设备组织成一个逻辑设备的模块，能够更好的管理磁盘，通过对底层的封装，对磁盘进行动态管理。
基本概念：
pv :physical volume物理卷处于最底层
vg :volume group卷组，建立在物理卷之上，最小单位为pe
lv :logical volume 逻辑卷建立在卷组之上，卷组中的未分配空间可以用于建立新的逻辑卷，逻辑卷建立后可以动态地扩展和缩小空间
管理使用：
| pv管理工具 | vg管理工具 | lv管理工具 |
|---|---|---|
| pvs:简要显示PV信息 | vgs :显示vg简要信息 | lvs :显示lv简要信息 |
| pvdisplay:显示详细信息 | vgdisplay 显示详细信息 | lvdisplay 显示详细信息 |
| pvcreate /dev/device... :创建PV | vgcreate [-s #[kKmMgGtTpPeE]] VG_Name /dev/device...]#创建vg，-s指明pe大小，默认4m | lvcreate -L #[mMgGtT] -n NAME VolumeGroup #-l 指明pe多少个 ,-L lv大小 |
| pvremove /dev/device...删除PV | vgextend VG_Name /dev/device... #扩容vg | lvextend -L [+]#[mMgGtT] /dev/VG_NAME/LV_NAME： lv扩容后还需要修改逻辑大小：resizefs /dev/VG_NAME/LV_NAME |
| pvmove /dev/device /dev/device:数据迁移 | vgreduce VG_Name /dev/device... #缩容 | 缩减逻辑卷看缩减步骤 |
| vgremove vg_name删除卷组 ：注收缩需先迁移数据 | lvremove /dev/VG_NAME/LV_NAME #删除逻辑卷 |
lv缩减步骤：
# umount /dev/VG_NAME/LV_NAME#先卸载，xfs可以不用卸载
# e2fsck -f /dev/VG_NAME/LV_NAME ：强制检测文件系统
# resize2fs /dev/VG_NAME/LV_NAME #[mMgGtT] #执行缩减操作
# lvreduce -L [-]#[mMgGtT] /dev/VG_NAME/LV_NAME #缩减lv
# mount简单实践：
[root@xt ~]# pvcreate /dev/sdb{1,2}
Physical volume "/dev/sdb1" successfully created.
Physical volume "/dev/sdb2" successfully created.
[root@xt ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 lvm2 --- 1.00g 1.00g
/dev/sdb2 lvm2 --- 1.00g 1.00g
[root@xt ~]# pvdisplay
"/dev/sdb2" is a new physical volume of "1.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb2
VG Name
PV Size 1.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 3XTOcT-uIc3-73Hc-alkn-EKWJ-yyqv-CZYDsR
"/dev/sdb1" is a new physical volume of "1.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 1.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID KZ6Mwf-GPQc-xGQf-xWwS-FCnS-yLtn-XqJofh
= ==================================================
[root@xt ~]# vgcreate myvg /dev/sdb1
Volume group "myvg" successfully created
[root@xt ~]# vgs
VG #PV #LV #SN Attr VSize VFree
myvg 1 0 0 wz--n- 1020.00m 1020.00m
[root@xt ~]# vgextend myvg /dev/sdb2
Volume group "myvg" successfully extended
[root@xt ~]# vgs
VG #PV #LV #SN Attr VSize VFree
myvg 2 0 0 wz--n- 1.99g 1.99g
[root@xt ~]# vgdisplay
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 1.99 GiB
PE Size 4.00 MiB
Total PE 510
Alloc PE / Size 0 / 0
Free PE / Size 510 / 1.99 GiB
VG UUID b5t7N7-xMBg-5O8w-xS5m-2OTV-IpBd-98mR5w
===================================================
[root@xt ~]# lvcreate -L 200m --name mylv myvg
Logical volume "mylv" created.
[root@xt ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
mylv myvg -wi-a----- 200.00m
[root@xt ~]# lvdisplay
--- Logical volume ---
LV Path /dev/myvg/mylv
LV Name mylv
VG Name myvg
LV UUID PelWrs-D13Q-8btE-q0RV-tFsA-6miC-FTqwns
LV Write Access read/write
LV Creation host, time xt.com, 2019-01-11 22:24:56 +0800
LV Status available
# open 0
LV Size 200.00 MiB
Current LE 50
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
=================================================
[root@xt ~]# mkfs.ext4 /dev/myvg/mylv
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
51200 inodes, 204800 blocks
10240 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=33816576
25 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
[root@xt ~]# mount /dev/myvg/mylv /mnt
[root@xt ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 10G 4.0G 6.1G 40% /
devtmpfs 984M 0 984M 0% /dev
tmpfs 993M 0 993M 0% /dev/shm
tmpfs 993M 8.7M 985M 1% /run
tmpfs 993M 0 993M 0% /sys/fs/cgroup
/dev/sda3 256M 83M 173M 33% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/mapper/myvg-mylv 190M 1.6M 175M 1% /mnt
==========================================
模拟数据迁移：需要同一个vg
[root@xt mnt]# mount /dev/myvg/mylv /mnt
[root@xt mnt]# cp -r /tmp/ /mnt/
[root@xt tmp]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a-- 1020.00m 820.00m #数据主要在sdb1,迁移到目标的容量要比现有大
/dev/sdb2 myvg lvm2 a-- 1020.00m 1020.00m
[root@xt tmp]# pvmove /dev/sdb1 /dev/sdb2
/dev/sdb1: Moved: 4.00%
/dev/sdb1: Moved: 100.00%
[root@xt tmp]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 myvg lvm2 a-- 1020.00m 1020.00m
/dev/sdb2 myvg lvm2 a-- 1020.00m 820.00m
[root@xt tmp]# vgreduce myvg /dev/sdb1
Removed "/dev/sdb1" from volume group "myvg"
[root@xt tmp]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 lvm2 --- 1.00g 1.00g
/dev/sdb2 myvg lvm2 a-- 1020.00m 820.00m
[root@xt tmp]# vgs
VG #PV #LV #SN Attr VSize VFree
myvg 1 1 0 wz--n- 1020.00m 820.00m