linux之lvm学习 (转载)
swency 2010-09-15
5月20号 更新：
今天把我本子上的 vmware上重新整了下，虚拟一个Linux ，实地演练下LVM
1.装好linux系统， 我给虚拟机开辟了一个 /dev/hda 硬盘，3G空间，为了实验LVM，我有给虚拟机添加了一块硬盘
/dev/hdb 2G 空间
注意： 我在虚拟机中装Linux的时候，遇到了 系统找不到 硬盘的情况，开始以为 光盘有问题，在网上重新下载了ISO包，安装，问题依旧，最后才发现我这个版本的vmware 对硬盘支持的类型只能是 IDE 的，改了 硬盘类型 就OK了
2. 使用 fdisk -l 查看磁盘 情况，可以看到 hdb 的类型是 linux
3. 将 hdb 从linux 改成 linux LVM,一定要使用 w 保存退出,再次查看 已经是linux lvm了
fdisk /dev/hdb ->m -> t -> 3 -> 8e -> w
[root@xhu-vm ~]# fdisk -l Disk /dev/hda: 3221 MB, 3221225472 bytes 255 heads, 63 sectors/track, 391 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/hda1 * 1 13 104391 83 Linux /dev/hda2 14 391 3036285 8e Linux LVM Disk /dev/hdb: 2147 MB, 2147483648 bytes 16 heads, 63 sectors/track, 4161 cylinders Units = cylinders of 1008 * 512 = 516096 bytes Device Boot Start End Blocks Id System /dev/hdb3 1 4161 2097112+ 8e Linux LVM
4.创建 PV
pvcreate/dev/hdb
查看创建好的pv[root@xhu-vm ~]# pvdisplay --- Physical volume --- PV Name /dev/hda2 VG Name VolGroup00 PV Size 2.88 GB / not usable 0 Allocatable yes PE Size (KByte) 32768 Total PE 92 Free PE 1 Allocated PE 91 PV UUID el1YY6-k7dU-V7mA-Uvyk-TNuH-Dnsm-yRBxDC --- NEW Physical volume --- PV Name /dev/hdb VG Name PV Size 2.00 GB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID r1uwvi-NhI1-bVS5-qfZQ-GR8M-VNkX-UW0Ajr
5.创建卷组
[root@xhu-vm ~]# vgcreate VolGroup01 /dev/hdb Volume group "VolGroup01" successfully created
查看卷组
[root@xhu-vm ~]# pvdisplay --- Physical volume --- PV Name /dev/hdb VG Name VolGroup01 PV Size 2.00 GB / not usable 0 Allocatable yes PE Size (KByte) 4096 Total PE 511 Free PE 511 Allocated PE 0 PV UUID r1uwvi-NhI1-bVS5-qfZQ-GR8M-VNkX-UW0Ajr --- Physical volume --- PV Name /dev/hda2 VG Name VolGroup00 PV Size 2.88 GB / not usable 0 Allocatable yes PE Size (KByte) 32768 Total PE 92 Free PE 1 Allocated PE 91 PV UUID el1YY6-k7dU-V7mA-Uvyk-TNuH-Dnsm-yRBxDC
或者这么查看
[root@xhu-vm ~]# vgdisplay --- Volume group --- VG Name VolGroup01 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 2.00 GB PE Size 4.00 MB Total PE 511 Alloc PE / Size 0 / 0 Free PE / Size 511 / 2.00 GB VG UUID bVxufu-AZWK-ifl2-e8OQ-AH7k-oMuR-Dkn5Cm --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 2.88 GB PE Size 32.00 MB Total PE 92 Alloc PE / Size 91 / 2.84 GB Free PE / Size 1 / 32.00 MB VG UUID jUbO2f-SWru-9BXD-Kp16-AGbp-0pQE-fw5YJ2
6. 激活卷组
[root@xhu-vm ~]# vgchange -a y VolGroup01 0 logical volume(s) in volume group "VolGroup01" now active [root@xhu-vm ~]#
7.创建逻辑卷(152M)
[root@xhu-vm ~]# lvcreate -L150 -nLogVol02 VolGroup01 /dev/cdrom: open failed: Read-only file system Rounding up size to full physical extent 152.00 MB Logical volume "LogVol02" created [root@xhu-vm ~]#
8.格式化文件系统 + mount 到 /data/wwwroot
[root@xhu-vm ~]# mkdir /data/wwwroot
[root@xhu-vm ~]# mkfs -V -t ext3 /dev/VolGroup01/LogVol02
mkfs version 2.12a (Dec 21 2004)
mkfs.ext3 /dev/VolGroup01/LogVol02
mke2fs 1.35 (28-Feb-2004)
max_blocks 159383552, rsv_groups = 19456, rsv_gdb = 256
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
38912 inodes, 155648 blocks
7782 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
19 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Writing inode tables: done
inode.i_blocks = 3074, i_size = 67383296
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 39 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@xhu-vm ~]# mount /dev/VolGroup01/LogVol02 /data/wwwroot
[root@xhu-vm ~]# 9. 拷贝一个文件到 /data/wwwroot
[root@xhu-vm wwwroot]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
2418944 1464868 831196 64% /
/dev/hda1 101086 9028 86839 10% /boot
none 128020 0 128020 0% /dev/shm
/dev/mapper/VolGroup01-LogVol02
150733 11554 131397 9% /data/wwwroot 注意：我创建的LogVol02 有152M，当你他的 mount点 /data/wwwroot 拷贝数据的时候，超过152M会报错，再次操作 /data/wwwroot 的时候会说 file system read only. 只要你增加了 这个lv的容量就万事OK了，可见LVM的好处
10.增加这个LV增加容量100M
lvextend-L+100/dev/VolGroup01/LogVol02
lvs看看现在的容量
11.减少LV的容量减少100M
lvreduce-L-100/dev/VolGroup01/LogVol02
12.在VolGroup01继续建立一个LVLogVol03
lvcreate -L150 -nLogVol03 VolGroup01参考：
虚拟机环境中linux系统增加磁盘空间
linux之lvm学习
硬盘分区如何设定大小,如何规划,再好的规划也有出差错的时候,人算不如天算.
为了让我们脱离那可悲的分区与分区修改工具,请跟我来认识一下LVM-逻辑卷管理(logical volume manager).首先先把基本术语定义讲一下:
LVM是linux对磁盘分区进行管理的一种机制.LVM是建立在磁盘与分区之上的一个逻辑层,以提高磁盘管理的灵活性.
在LVM内有三个基本术语PV(PhysicalVolume物理卷)VG(VolumeGroup卷组)LV(LogicalVolume逻辑卷)
三者的关系为,先建立PV,根据PV组合或扩展形成VG,根据用户需求使用VG卷的总量去建立相应的LV卷(个人理解)
一.创建PV的命令与方法
1.查看磁盘分区情况:
[root@localhost /]# fdisk -l /dev/hdbDisk /dev/hdb: 21.4 GB, 21474836480 bytes
15heads,63sectors/track,44384cylinders
Units = cylinders of 945 * 512 = 483840 bytesDevice Boot Start End Blocks Id System
/dev/hdb11100004724968+83Linux
/dev/hdb21000120000472500083Linux
/dev/hdb32000130000472500083Linux
/dev/hdb43000144384679644083Linux
共计4个分区请大家看ID位置代码:83system:linux,我们需要更改ID代码为8e此为LVM卷分区标签
分区系统号更改方法如下:
[root@localhost/]#fdisk/dev/hdb
Command(mforhelp):t
Partitionnumber(1-4):1
Hexcode(typeLtolistcodes):8e
Changedsystemtypeofpartition1to8e(LinuxLVM)
此时系统ID已经更改为LVM,我们再用FDISK命令查看一下磁盘情况
[root@localhost /]# fdisk -l /dev/hdbDisk /dev/hdb: 21.4 GB, 21474836480 bytes
15heads,63sectors/track,44384cylinders
Units = cylinders of 945 * 512 = 483840 bytesDevice Boot Start End Blocks Id System
/dev/hdb11100004724968+8eLinuxLVM
/dev/hdb2100012000047250008eLinuxLVM
SYStem类型:LinuxLVM,此时我们可以创建PV了,我创建了二个PV,通过pvdisplay命令可以查看创建的PV卷的情况.
[root@localhost/]#pvcreate/dev/hdb1/dev/hdb2
Physicalvolume"/dev/hdb1"successfullycreated
Physicalvolume"/dev/hdb2"successfullycreated
查看PV卷详细信息:
[root@localhost/]#pvdisplay
"/dev/hdb1"isanewphysicalvolumeof"4.51GB"
---NEWPhysicalvolume---
PVName/dev/hdb1
VGName
PVSize4.51GB
AllocatableNO
PESize(KByte)0
TotalPE0
FreePE0
AllocatedPE0
PVUUIDgSv31K-01SU-1Vbm-HF26-MR5W-wgBw-1EeHb0
"/dev/hdb2"isanewphysicalvolumeof"4.51GB"
---NEWPhysicalvolume---
PVName/dev/hdb2
VGName
PVSize4.51GB
AllocatableNO
PESize(KByte)0
TotalPE0
FreePE0
AllocatedPE0
PVUUIDODEuTv-iMqs-Wzxq-HMyB-yUw2-Lnwn-5JdlSp
我们此时再回看查看一下磁盘分区的情况.
[root@localhost /]# fdisk -l /dev/hdbDisk /dev/hdb: 21.4 GB, 21474836480 bytes
15heads,63sectors/track,44384cylinders
Units = cylinders of 945 * 512 = 483840 bytesDevice Boot Start End Blocks Id System
/dev/hdb11100004724968+8eLinuxLVM
/dev/hdb2100012000047250008eLinuxLVM
/dev/hdb3200013000047250008eLinuxLVM
/dev/hdb4300014438467964408eLinuxLVM
PV创建完成,相应的命令如下:pvcreate(PV创建)pvdisplay(PV信息查看)pvremove(pv卷删除)
pvremove /dev/hdb1 (删除命令例)参考：
合理规划您的硬盘分区
http://hi.baidu.com/sinyo/blog/item/d793be3e866682f9828b13c6.html
http://blog.csdn.net/steelren/archive/2007/12/12/1931363.aspx
利用lvm增加linux根分区的容量
http://www.opsers.org/base/linux-root-partition-using-lvm-the-capacity-to-increase.html
