mkfs.ext4 /dev/sdb1
mkfs.xfs /dev/sdb2
mkfs.vfat /dev/sdb1
mkswap /dev/vdb
一. 概念
1. 关键字
LVM逻辑卷管理 (Logical Volume Manager) 物理存储介质 (The physical media) 系统的存储设备硬件, 如硬盘:/dev/hda,/dev/sda,/dev/vda 等,是存储系统的基础 物理卷(PV,physicalvolume) 物理卷是LVM逻辑卷 管理系统 最底层。包含逻辑卷管理相关的管理参数,可以是整个物理硬盘或实际物理硬盘上的分区。如:硬盘的MBR分区或GPT分区,还有RAID,回环文件等 卷组(VG,Volume Group) 卷组是一个或多个物理卷的集合,并在设备的文件系统中显示为 /dev/VG_NAME 逻辑卷(LV,logicalvolume) 逻辑卷建立在卷组基础上,由物理块PE组成,是一个虚拟分区,显示为 /dev/VG_NAME/LV_NAME 卷组中未分配的空间可用于建立新的逻辑卷,逻辑卷建立后可以动态扩展和缩小空间。在逻辑卷之上可以建立文件系统(比如/home或者/usr等) 物理块(PE,physical extent) 每一个物理卷被划分为 称为PE的基本单元—物理块。物理块PE是一个卷组中最小的物理区域存储单元,默认为4 MiB(大小可设置) 同一卷组所有PV的PE大小需一致,新的pv加入到vg后,pe的大小自动更改为vg中定义的pe大小
2. 原理
LVM的工作原理其实很简单,它就是通过将底层的物理硬盘抽象的封装起来,然后以逻辑卷的方式呈现给上层应用。在传统的磁盘管理机制中,我们的上层应用是直接访问文件系统,从而对底层的物理硬盘进行读取,而在LVM中,其通过对底层的硬盘进行封装,当我们对底层的物理硬盘进行操作时,其不再是针对于分区进行操作,而是通过一个叫做逻辑卷的东西来对其进行底层的磁盘管理操作。比如说我增加一个物理硬盘,这个时候上层的服务是感觉不到的,因为呈现给上层服务的是以逻辑卷的方式 LVM最大的特点就是可以对磁盘进行动态管理。因为逻辑卷的大小是可以动态调整的,而且不会丢失现有的数据。如果我们新增加了硬盘,其也不会改变现有上层的逻辑卷。作为一个动态磁盘管理机制,逻辑卷技术大大提高了磁盘管理的灵活性
3. 优点
比起传统的硬盘分区管理方式,LVM更富有灵活性,可以将多块硬盘看做一个大硬盘, 可以创建跨众多硬盘空间的分区 在调整逻辑卷(LV)大小时可以不用考虑逻辑卷在硬盘上的位置,不用担心没有可用的连续空间
二. 操作案例
1. 基于创建
yum -y install lvm2
[ root@lvm ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8 :0 0 20G 0 disk
└─sda1 8 :1 0 20G 0 part /
sdb 8 :16 0 40G 0 disk
sdc 8 :32 0 10G 0 disk
sr0 11 :0 1 973M 0 rom
[ root@lvm ~] Physical volume "/dev/sdb" successfully created.Physical volume "/dev/sdc" successfully created.
[ root@lvm ~] PV VG Fmt Attr PSize PFree /dev/sdb lvm2 --- 40 .00g 40 .00g/dev/sdc lvm2 --- 10 .00g 10 .00g
pvscan
[ root@lvm ~] Volume group "yaya" successfully created
[ root@lvm ~] VG yaya 2 0 0 wz--n- 49 .99g 49 .99g
[ root@lvm ~] Logical volume "Moon001" created.
[ root@lvm ~] Logical volume "Moon002" created.
[ root@lvm ~] Logical volume "Moon003" created.
[ root@lvm ~] LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync ConvertMoon001 yaya -wi-a----- 10 .00g Moon002 yaya -wi-a----- 5 .00g Moon003 yaya -wi-a----- 5 .00g
[ root@lvm ~] ACTIVE '/dev/yaya/Moon001' [ 10.00 GiB] inheritACTIVE '/dev/yaya/Moon002' [ 5.00 GiB] inheritACTIVE '/dev/yaya/Moon003' [ 5.00 GiB] inherit
[ root@lvm ~] --- Volume group ---VG Name yayaSystem ID Format lvm2Metadata Areas 2 Metadata Sequence No 4 VG Access read/writeVG Status resizableMAX LV 0 Cur LV 3 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 49.99 GiBPE Size 4.00 MiBTotal PE 12798 Alloc PE / Size 5120 / 20.00 GiBFree PE / Size 7678 / 29.99 GiBVG UUID P52FYJ-i06q-rifK-W7Nf-HjCN-4gmb-ZVj7KC
[ root@lvm ~] VG yaya 2 3 0 wz--n- 49 .99g 29 .99g
[ root@lvm ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8 :0 0 20G 0 disk
└─sda1 8 :1 0 20G 0 part /
sdb 8 :16 0 40G 0 disk
├─yaya-Moon001 253 :0 0 10G 0 lvm
├─yaya-Moon002 253 :1 0 5G 0 lvm
└─yaya-Moon003 253 :2 0 5G 0 lvm
sdc 8 :32 0 10G 0 disk
sr0 11 :0 1 973M 0 rom
[ root@lvm ~]
total 0
lrwxrwxrwx 1 root root 7 Mar 14 22 :13 Moon001 -> .. /dm-0
lrwxrwxrwx 1 root root 7 Mar 14 22 :13 Moon002 -> .. /dm-1
lrwxrwxrwx 1 root root 7 Mar 14 22 :13 Moon003 -> .. /dm-2
mkfs.ext4 /dev/yaya/Moon001
mkfs.xfs /dev/yaya/Moon002
mkfs.vfat /dev/yaya/Moon003
[ root@lvm ~]
mke2fs 1.42 .9 ( 28 -Dec-2013)
Filesystem label =
OS type: Linux
Block size = 4096 ( log= 2 )
Fragment size = 4096 ( log= 2 )
Stride = 0 blocks, Stripe width = 0 blocks
655360 inodes, 2621440 blocks
131072 blocks ( 5.00 %) reserved for the super user
First data block = 0
Maximum filesystem blocks = 2151677952
80 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 32768 , 98304 , 163840 , 229376 , 294912 , 819200 , 884736 , 1605632 Allocating group tables: done
Writing inode tables: done
Creating journal ( 32768 blocks) : done
Writing superblocks and filesystem accounting information: done
mkdir /Moon-{ a,b,c} mount /dev/yaya/Moon001 /Moon-a
mount /dev/yaya/Moon002 /Moon-b
mount /dev/yaya/Moon003 /Moon-c
[ root@lvm ~]
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 943M 0 943M 0 % /dev
tmpfs tmpfs 954M 0 954M 0 % /dev/shm
tmpfs tmpfs 954M 10M 944M 2 % /run
tmpfs tmpfs 954M 0 954M 0 % /sys/fs/cgroup
/dev/sda1 xfs 22G 2 .0G 20G 9 % /
tmpfs tmpfs 191M 0 191M 0 % /run/user/0
/dev/mapper/yaya-Moon001 ext4 11G 38M 9 .9G 1 % /Moon-a
/dev/mapper/yaya-Moon002 xfs 5 .4G 34M 5 .4G 1 % /Moon-b
/dev/mapper/yaya-Moon003 vfat 5 .4G 4 .1k 5 .4G 1 % /Moon-c
vim /etc/fstabUUID = 85fd024b-5296-406d-a63b-50f19e292839 / xfs defaults 0 0
/dev/yaya/Moon001 /Moon-a ext4 defaults 0 0
/dev/yaya/Moon002 /Moon-b xfs defaults 0 0
/dev/yaya/Moon003 /Moon-c vfat defaults 0 0
2. 基于追加
[ root@lvm ~]
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8 :0 0 20G 0 disk
└─sda1 8 :1 0 20G 0 part /
sdb 8 :16 0 40G 0 disk
├─yaya-Moon001 253 :0 0 12G 0 lvm
├─yaya-Moon002 253 :1 0 7G 0 lvm
└─yaya-Moon003 253 :2 0 7 .5G 0 lvm
sdc 8 :32 0 10G 0 disk
sdd 8 :48 0 20G 0 disk
sr0 11 :0 1 973M 0 rom
pvcreate /dev/sdd[ root@lvm ~] Physical volume "/dev/sdd" successfully created.
[ root@lvm ~] PV /dev/sdb VG yaya lvm2 [ < 40.00 GiB / < 13.50 GiB free] PV /dev/sdc VG yaya lvm2 [ < 10.00 GiB / < 10.00 GiB free] PV /dev/sdd lvm2 [ 20.00 GiB] Total: 3 [ 69.99 GiB] / in use: 2 [ 49.99 GiB] / in no VG: 1 [ 20.00 GiB]
vgextend yaya /dev/sdd[ root@lvm ~] Volume group "yaya" successfully extended
[ root@lvm ~] PV /dev/sdb VG yaya lvm2 [ < 40.00 GiB / < 13.50 GiB free] PV /dev/sdc VG yaya lvm2 [ < 10.00 GiB / < 10.00 GiB free] PV /dev/sdd VG yaya lvm2 [ < 20.00 GiB / < 20.00 GiB free] Total: 3 [ < 69.99 GiB] / in use: 3 [ < 69.99 GiB] / in no VG: 0 [ 0 ]
lvextend -l +100%FREE /dev/yaya/Moon002
xfs_growfs /dev/yaya/Moon002
resize2fs /dev/yaya/Moon001
3. 逻辑卷扩容
[ root@lvm ~] Size of logical volume yaya/Moon002 changed from 5.00 GiB ( 1280 extents) to 7.00 GiB ( 1792 extents) .Logical volume yaya/Moon002 successfully resized.
meta-data= /dev/mapper/yaya-Moon002 isize = 512 agcount = 4 , agsize = 327680 blks= sectsz = 512 attr = 2 , projid32bit = 1 = crc = 1 finobt = 0 spinodes = 0
data = bsize = 4096 blocks = 1310720 , imaxpct = 25 = sunit = 0 swidth = 0 blks
naming = version 2 bsize = 4096 ascii-ci= 0 ftype = 1
log = internal bsize = 4096 blocks = 2560 , version = 2 = sectsz = 512 sunit = 0 blks, lazy-count= 1
realtime = none extsz = 4096 blocks = 0 , rtextents = 0
[ root@lvm ~]
Filesystem Size Used Avail Use% Mounted on
devtmpfs 900M 0 900M 0 % /dev
tmpfs 910M 0 910M 0 % /dev/shm
tmpfs 910M 9 .5M 901M 2 % /run
tmpfs 910M 0 910M 0 % /sys/fs/cgroup
/dev/sda1 20G 1 .8G 19G 9 % /
tmpfs 182M 0 182M 0 % /run/user/0
/dev/mapper/yaya-Moon001 12G 41M 12G 1 % /Moon-a
/dev/mapper/yaya-Moon002 7 .0G 33M 7 .0G 1 % /Moon-b
/dev/mapper/yaya-Moon003 5 .0G 4 .0K 5 .0G 1 % /Moon-c