LVM———Logical Volume Manager(邏輯卷管理器)的簡(jiǎn)寫(xiě)。LVM可以幫助我們?yōu)閼门c用戶(hù)方便地分配存儲空間。在LVM管理下的邏輯卷可以按需改變大小或添加移除。LVM也允許按用戶(hù)組對存儲卷進(jìn)行管理，允許管理員用更直觀(guān)的名稱(chēng)(如"sales','development')代替物理磁盤(pán)(如'sda','sdb')來(lái)標識存儲卷。
傳統分區概念
LVM邏輯卷管理
磁盤(pán)空間獨立性不能充分利用，尤其是一個(gè)FS只能對應一個(gè)分區多磁盤(pán)PV組成存儲池VG，再根據應用細分邏輯卷LV，空間利用率提高
空間擴展性重新分區采取靜態(tài)或動(dòng)態(tài)在線(xiàn)擴展卷組容量
數據備份業(yè)務(wù)繁忙時(shí)，I/O接口讀寫(xiě)頻繁可采取快照方式捕捉某一邏輯卷的瞬間精確拷貝已完成在線(xiàn)備份工作
用戶(hù)使用性分區標識無(wú)法滿(mǎn)足大量用戶(hù)要求可根據用戶(hù)需求定義lv邏輯卷的卷標
一、創(chuàng )建LVM的準備工作
1.搭建環(huán)境：OS:RHEL5.3
LVM包
IDE磁盤(pán)/dev/hdb(1024MB),/dev/hdd(1024MB)
2.轉換磁盤(pán)分區——>lvm卷分區
最終方案：/dev/hdb ——> 創(chuàng )建 /dev/hdb1(Id:5,System:Extended)
/dev/hdb5(Id:8e,System:Linux LVM)
/dev/hdd ——> 創(chuàng )建 /dev/hdd1(Id:5,System:Extended)
/dev/hdd5(Id:8e,System:Linux LVM)
操作：(僅以/dev/hdb為例)
#fdisk /dev/hdb
#p(顯示分區情況)——>#n(新建分區)——>#e(創(chuàng )建擴展分區)——>#l(創(chuàng )建邏輯分區)
#此處為實(shí)驗環(huán)境方便后面的增減操作，所以我們將/dev/hdb全部劃分為一個(gè)分區
#t(設置磁盤(pán)Hex code)——>#8e(LinuxLVM)——>#w(保存操作)
#p
Disk /dev/hdb: 1073 MB, 1073741824 bytes
16 heads, 63 sectors/track, 2080 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Device Boot Start End Blocks Id System
/dev/hdb1 1 2080 1048288+ 5 Extended
/dev/hdb5 1 2080 1048257 8e Linux LVM
#partprobe (此命令讓kernel會(huì )重新讀取磁盤(pán)分區表，修改生效)
二、創(chuàng )建LVM
1.創(chuàng )建PV盤(pán)
方案： /dev/hdb ——> lvm2[1024MB]
/dev/hdd ——> lvm2[1024MB]
操作:
#pvcreate /dev/hdb5 /dev/hdd5
#pvscan
#pvdisplay
"/dev/hdb5" is a new physical volume of "1023.69 MB"
--- NEW Physical volume ---
PV Name /dev/hdb5
VG Name
PV Size 1023.69 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID zM7103-SJg4-ZjOb-BeL0-dlR1-HHh6-HCG8kG
"/dev/hdd5" is a new physical volume of "1023.69 MB"
--- NEW Physical volume ---
PV Name /dev/hdd5
VG Name
PV Size 1023.69 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID hAk1Dx-QulA-YV4G-p8wa-7sWw-FiaC-10GorS
2.創(chuàng )建VG存儲池
方案： lvm2(/dev/hdb)——> vg1
lvm2(/dev/hdd)——> vg2
操作：
#vgcreate vg1 /dev/hdb5
#vgcreate vg2 /dev/hdd5
#vgscan
#vgdisplay
--- Volume group ---
VG Name vg2
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 1020.00 MB
PE Size 4.00 MB
Total PE 255
Alloc PE / Size 0 / 0
Free PE / Size 255 / 1020.00 MB
VG UUID Wa4Jo8-k3xY-BTng-uV6j-0Ee1-Vp8b-fNVrhQ
--- Volume group ---
VG Name vg1
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 1020.00 MB
PE Size 4.00 MB
Total PE 255
Alloc PE / Size 0 / 0
Free PE / Size 255 / 1020.00 MB
VG UUID UGjfZd-shth-ZRTU-sVVm-MD0s-wzVB-zd7Uwt
3.分配LV邏輯卷
方案： work(/dev/hdb5)——> vg1
Study(/dev/hdd5)——> vg2
操作：
#lvcreate –L 500M –n work vg1
#lvcreate –L 500M –n study vg2
#lvscan
#lvdisplay
--- Logical volume ---
LV Name /dev/vg2/study
VG Name vg2
LV UUID 53VT9v-dyp0-lSST-eDFz-w2Ns-Os0Z-ERnqVU
LV Write Access read/write
LV Status available
# open 0
LV Size 500.00 MB
Current LE 125
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Logical volume ---
LV Name /dev/vg1/work
VG Name vg1
LV UUID lhgKVg-hi95-W9gw-wOkZ-uyuy-BgZp-RrsCcA
LV Write Access read/write
LV Status available
# open 0
LV Size 500.00 MB
Current LE 125
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
4.分區格式化
#mkfs.ext3 /dev/vg1/work //或 #mkfs -j /dev/vg1/work
#mkfs.ext3 /dev/vg2/study //...
#df –l
Disk /dev/hda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 32 257008+ 83 Linux
/dev/hda2 33 97 522112+ 83 Linux
/dev/hda3 98 358 2096482+ 83 Linux
/dev/hda4 359 1044 5510295 5 Extended
/dev/hda5 359 549 1534176 83 Linux
/dev/hda6 550 848 2401686 83 Linux
/dev/hda7 849 913 522081 82 Linux swap / Solaris
/dev/hda8 914 978 522081 83 Linux
/dev/hda9 979 1043 522081 83 Linux
Disk /dev/hdb: 1073 MB, 1073741824 bytes
16 heads, 63 sectors/track, 2080 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Device Boot Start End Blocks Id System
/dev/hdb1 1 2080 1048288+ 5 Extended
/dev/hdb5 1 2080 1048257 8e Linux LVM
Disk /dev/hdd: 1073 MB, 1073741824 bytes
16 heads, 63 sectors/track, 2080 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Device Boot Start End Blocks Id System
/dev/hdd1 1 2080 1048288+ 5 Extended
/dev/hdd5 1 2080 1048257 8e Linux LVM
5.掛載新分區
#mkdir ../home/work ../home/study
#mount ../dev/vg1/work ../home/work
#mount ../dev/vg2/study ../home/study
#df –Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/hda2 ext3 494M 212M 257M 46% /
/dev/hda9 ext3 494M 45M 425M 10% /var
/dev/hda8 ext3 494M 11M 458M 3% /opt
/dev/hda6 ext3 2.3G 68M 2.1G 4% /home
/dev/hda3 ext3 2.0G 1.7G 182M 91% /usr
/dev/hda5 ext3 1.5G 35M 1.4G 3% /usr/local
/dev/hda1 ext3 244M 12M 219M 6% /boot
tmpfs tmpfs 125M 0 125M 0% /dev/shm
/dev/mapper/vg1-work
ext3 485M 11M 449M 3% /home/work
/dev/mapper/vg2-study
ext3 485M 11M 449M 3% /home/study
