LVM逻辑卷管理
实验：
本实验在虚拟机运行，运行时需要增加一块硬盘分区:
分区：
fdisk /dev/sdb
Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 2610 20964793+ 5 Extended
/dev/sdb5 1 244 1959867 8e Linux LVM
/dev/sdb6 245 488 1959898+ 8e Linux LVM
/dev/sdb7 489 732 1959898+ 8e Linux LVM
/dev/sdb8 733 976 1959898+ 8e Linux LVM
加入物理卷：
pvcreate /dev/sdb
sdb sdb1 sdb5 sdb6 sdb7 sdb8
[root @localhost ~]# pvcreate /dev/sdb{5,6,7,8}
Physical volume "/dev/sdb5" successfully created
Physical volume "/dev/sdb6" successfully created
Physical volume "/dev/sdb7" successfully created
Physical volume "/dev/sdb8" successfully created
查看物理卷信息：
pvdisplay
"/dev/sdb8" is a new physical volume of "1.87 GB"
--- NEW Physical volume ---
PV Name /dev/sdb8 #实际分区设备名称
VG Name #因为尚未分配出去所以空白
PV Size 1.87 GB #容量
Allocatable NO #是否已被分配，结果是NO
PE Size (KByte) 0 #在此PV内的PE大小
Total PE 0 #共分出几个PE
Free PE 0 #没被LV用掉的PE
Allocated PE 0 #尚可分配出去的PE容量
PV UUID q5NEcF-WC6V-XoH5-sSRk-EcE2-dSRk-oelHhJ
新建VG卷：
vgcreate -s 16M vgyi /dev/sdb{5,6,7} #PE的大小为16M
Volume group "vgyi" successfully created
查看VG：
pvscan
PV /dev/sdb5 VG vgyi lvm2 [1.86 GB / 1.86 GB free]
PV /dev/sdb6 VG vgyi lvm2 [1.86 GB / 1.86 GB free]
PV /dev/sdb7 VG vgyi lvm2 [1.86 GB / 1.86 GB free]
PV /dev/sda2 VG VolGroup00 lvm2 [19.88 GB / 0 free]
PV /dev/sdb8 lvm2 [1.87 GB] #sdb8没有加入VG
Total: 5 [27.32 GB] / in use: 4 [25.45 GB] / in no VG: 1 [1.87 GB]
vgdisplay
--- Volume group ---
VG Name vgyi
System ID
Format lvm2
Metadata Areas 3
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 3
Act PV 3
VG Size 5.58 GB #整体的VG容量有这么大
PE Size 16.00 MB #内部每个PE的大小
Total PE 357 #总共的PE数量共有这么多
Alloc PE / Size 0 / 0
Free PE / Size 357 / 5.58 GB
VG UUID pW0cZ4-4YYv-aKIf-PNCo-G2gi-joPu-MxMOsp
往VG里添加一个PV：
vgextend vgyi /dev/sdb8
Volume group "vgyi" successfully extended
建立LV:
lvcreate -L +5.58G -n lvyi vgyi
Rounding up size to full physical extent 5.59 GB
Logical volume "lvyi" created
也可用PE方式创建：
lvcreate -l 357 -n lvpure vgyi
Logical volume "lvpure" created
查看LV容量：
lvdisplay
--- Logical volume ---
LV Name /dev/vgyi/lvpure
VG Name vgyi
LV UUID fE5ZQ9-nShY-wEh8-jb0s-Mku4-YwmW-ZycS7J
LV Write Access read/write
LV Status available
# open 0
LV Size 5.58 GB #lv的总容量
Current LE 357
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
挂载和格式化：
mkfs -t ext3 /dev/vgyi/lvpure mkdir /dd mount /dev/vgyi/lvpure /dd df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
19G 3.1G 15G 18% /
/dev/sda1 99M 12M 82M 13% /boot
tmpfs 1014M 0 1014M 0% /dev/shm
/dev/mapper/vgyi-lvpure
5.5G 140M 5.1G 3% /dd
cp -a /etc /var/log /dd #放点东西在里做验证
放大LV容量：
再在添加的磁盘上创建一个容量一样的分区：
fdisk /dev/sdb
/dev/sdb9 977 1220 1959898+ 8e Linux LVM
新建新的PV：
pvcreate /dev/sdb9
Physical volume "/dev/sdb9" successfully created
pvscan
PV /dev/sdb5 VG vgyi lvm2 [1.86 GB / 0 free]
PV /dev/sdb6 VG vgyi lvm2 [1.86 GB / 0 free]
PV /dev/sdb7 VG vgyi lvm2 [1.86 GB / 0 free]
PV /dev/sdb8 VG vgyi lvm2 [1.86 GB / 1.86 GB free]
PV /dev/sda2 VG VolGroup00 lvm2 [19.88 GB / 0 free]
PV /dev/sdb9 lvm2 [1.87 GB]
加大VG：
vgextend vgyi /dev/sdb9
Volume group "vgyi" successfully extended
vgdisplay
--- Volume group ---
VG Name vgyi
System ID
Format lvm2
Metadata Areas 5
Metadata Sequence No 8
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 5
Act PV 5
VG Size 9.30 GB
PE Size 16.00 MB
Total PE 595
Alloc PE / Size 357 / 5.58 GB
Free PE / Size 238 / 3.72 GB
VG UUID pW0cZ4-4YYv-aKIf-PNCo-G2gi-joPu-MxMOsp
加大LV：
lvresize -L +2G /dev/vgyi/lvpure
Extending logical volume lvpure to 7.58 GB
Logical volume lvpure successfully resized
#这样就增加了，lvresize的语法基本上通过-l跟-L来增加
#要增加用+，要减少用-
查看lv：
lvdisplay
--- Logical volume ---
LV Name /dev/vgyi/lvpure
VG Name vgyi
LV UUID fE5ZQ9-nShY-wEh8-jb0s-Mku4-YwmW-ZycS7J
LV Write Access read/write
LV Status available
# open 1
LV Size 7.58 GB
Current LE 485
Segments 5
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
df -h /dd
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vgyi-lvpure
5.5G 140M 5.1G 3% /dd
#lv卷的容量还是没有增加，用以下方法
dumpe2fs /dev/vgyi/lvpure resize2fs /dev/vgyi/lvpure df -h /dd
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vgyi-lvpure
7.5G 141M 7.0G 2% /dd
#容量就增加了，查看下磁盘里的东西
ll /dd
total 40
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 14 root root 4096 May 19 12:49 log
drwx------ 2 root root 16384 May 19 12:32 lost+found
#东西都还在
缩小LV容量：
e2fsck -f /dev/vgyi/lvpure resize2fs /dev/vgyi/lvpure 5G
#“resize2fs /dev/vgyi/lvpure 5G
”重新分配lv卷的大小，如果你写1G那么你的卷挂载上只有1G了
#反过来说你写10G那么它就只有10G大。
mount /dev/vgyi/lvpure /dd df -h /dd
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vgyi-lvpure
5.0G 240M 4.6G 5% /dd
LVM的系统快照：
lvcreate -L 1G -s -n lvbb /dev/vgyi/lvpure
Logical volume "lvbb" created
#-s是创建快照的意思
lvdisplay
--- Logical volume ---
LV Name /dev/vgyi/lvbb
VG Name vgyi
LV UUID 9fBl0m-a8qI-KcQn-30hW-botf-5CnF-zusgKQ
LV Write Access read/write
LV snapshot status active destination for /dev/vgyi/lvpure
LV Status available
# open 0
LV Size 7.58 GB #被快照的园LV容量
Current LE 485
COW-table size 1.00 GB #实际容量
COW-table LE 64
Allocated to snapshot 0.00%
Snapshot chunk size 4.00 KB
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3
mkdir /dd1 mount /dev/vgyi/lv
lvbb lvpure
mount /dev/vgyi/lvbb /dd1 df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
19G 3.1G 15G 18% /
/dev/sda1 99M 12M 82M 13% /boot
tmpfs 1014M 0 1014M 0% /dev/shm
/dev/mapper/vgyi-lvpure
5.0G 240M 4.6G 5% /dd
/dev/mapper/vgyi-lvbb
5.0G 240M 4.6G 5% /dd1
umount /dd1/ ll /dd
total 40
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 14 root root 4096 May 19 12:49 log
drwx------ 2 root root 16384 May 19 12:32 lost+found
rm rm -rf /dd/log/ cp -a /boot /lib /sbin /dd
dd/ dd1/
cp -a /boot /lib /sbin /dd ll /dd
total 64
drwxr-xr-x 4 root root 4096 Dec 27 2009 boot
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 13 root root 4096 May 19 12:48 lib
drwx------ 2 root root 16384 May 19 12:32 lost+found
drwxr-xr-x 2 root root 12288 May 19 12:49 sbin
mount /dev/vgyi/lvbb /dd1 df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
19679908 3244092 15420008 18% /
/dev/sda1 101086 12058 83809 13% /boot
tmpfs 1037728 0 1037728 0% /dev/shm
/dev/mapper/vgyi-lvpure
5161216 357596 4646336 8% /dd
/dev/mapper/vgyi-lvbb
5161216 245728 4758204 5% /dd1
tar zcfv ddd.tar.gz /dd1/*
#把备份区的东西压缩出来
umount /dd1 lvremove /dev/vgyi/lvbb
Do you really want to remove active logical volume lvbb? [y/n]: y
Logical volume "lvbb" successfully removed
umount /dd #卸载分区 mkfs -t ext3 /dev/vgyi/lvpure #格式化分区 mount /dev/vgyi/lvpure /dd/ #重新挂载 tar zxfv ddd.tar.gz -C /dd/ #吧刚才备份分区的压缩包解压到挂载目录 ll /dd/
total 20
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 14 root root 4096 May 19 12:49 log
drwx------ 2 root root 4096 May 19 12:32 lost+found
东西又回来了。
快照实验二：
lvcreate -s -L 1.5G -n lvdd /dev/vgyi/lvpure
Logical volume "lvdd" created
umount /dd/ mount /dev/vgyi/lvdd /dd1/ df -h /dev/vgyi/lvdd
Filesystem Size Used Avail Use% Mounted on
- 1014M 88K 1014M 1% /dev
rm -rf /dd1/log/ /dd1/etc/ cp -a /boot/ /lib /sbin /dd1/ ll /dd1/
total 36
drwxr-xr-x 4 root root 4096 Dec 27 2009 boot
drwxr-xr-x 13 root root 4096 May 19 12:48 lib
drwx------ 2 root root 4096 May 19 12:32 lost+found
drwxr-xr-x 2 root root 12288 May 19 12:49 sbin #跟原本的数据有差异了
mount /dev/vgyi/lvpure /dd/ ll /dd/
total 20
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 14 root root 4096 May 19 12:49 log
drwx------ 2 root root 4096 May 19 12:32 lost+found
#原本的数据没有改变
还原快照区域的数据，跟主文件信息相同
umount /dd1/ lvremove /dev/vgyi/lvdd
Do you really want to remove active logical volume lvdd? [y/n]:
y
Logical volume "lvdd" successfully removed
lvcreate -s -L 1.5G -n lvdd /dev/vgyi/lvpure
Logical volume "lvdd" created
mount /dev/vgyi/lvdd /dd1/ ll /dd1/
total 20
drwxr-xr-x 102 root root 12288 May 19 12:49 etc
drwxr-xr-x 14 root root 4096 May 19 12:49 log
drwx------ 2 root root 4096 May 19 12:32 lost+found
#这样快照区域的数据又复原了
LVM的关闭：
umount /dd1/ umount /dd lvremove /dev/vgyi/lvdd
Do you really want to remove active logical volume lvdd? [y/n]:
y
Logical volume "lvdd" successfully removed
[root @localhost ~]# lvremove /dev/vgyi/lvpure
Do you really want to remove active logical volume lvpure? [y/n]:
y
Logical volume "lvpure" successfully removed
vgchange -a n vgyi
0 logical volume(s) in volume group "vgyi" now active
[root @localhost ~]# vgremove vgyi
Volume group "vgyi" successfully removed
pvremove /dev/sdb{5,6,7,8,9}
Labels on physical volume "/dev/sdb5" successfully wiped
Labels on physical volume "/dev/sdb6" successfully wiped
Labels on physical volume "/dev/sdb7" successfully wiped
Labels on physical volume "/dev/sdb8" successfully wiped
Labels on physical volume "/dev/sdb9" successfully wiped
#如果在/etc/fstab下面写的还有开机启动LVM的话，把那条信息删除
#再把磁盘的类型改为82就行了
#创建顺序：PV--VG--LV