Linux上扩展磁盘空间

Linux上如何扩展磁盘？

有两种情况：

1、当有一个空间充足的盘时，可以直接使用fdisk -m来将磁盘分区，然后格式化，最后mount使用即可

[root@cimdb:/dev] fdisk /dev/sdb

Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel

Building a new DOS disklabel. Changes will remain in memory only,

until you decide to write them. After that, of course, the previous

content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): m

Command action

a toggle a bootable flag

b edit bsd disklabel

c toggle the dos compatibility flag

d delete a partition

l list known partition types

m print this menu

n add a new partition

o create a new empty DOS partition table

p print the partition table

q quit without saving changes

s create a new empty Sun disklabel

t change a partition's system id

u change display/entry units

v verify the partition table

w write table to disk and exit

x extra functionality (experts only)

Command (m for help): n

Command action

e extended

p primary partition (1-4)

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2、当每个磁盘空间较小，现在需要将这些小盘组合成一个大的空间来使用，需要使用到逻辑卷组管理来将这些小盘空间拼接在一起

假设现在有/dev/sdb 1G ,/dev/sdc 1G ,/dev/sdd 1G ,/dev/sde 2G ,/dev/sdf 10G盘已经划好，需要使用lvm 来管理。

[root@cimdb:~] fdisk -l 查看系统中有哪些盘没有分区

[root@cimdb:~] pvcreate /dev/sdb 将/dev/sdb 创建成一个物理卷

Writing physical volume data to disk "/dev/sdb"

Physical volume "/dev/sdb" successfully created

[root@cimdb:~] pvdisplay 查看系统中的物理卷信息

"/dev/asm-diskb" is a new physical volume of "1.00 GB"

--- NEW Physical volume ---

PV Name /dev/asm-diskb

VG Name

PV Size 1.00 GB

Allocatable NO

PE Size (KByte) 0

Total PE 0

Free PE 0

Allocated PE 0

PV UUID FlLxh4-PGff-Yoqd-SfKE-vKHe-iDLx-7rxQaE

[root@cimdb:~] vgcreate VolGroup00 /dev/sdb 创建一个物理卷组VolGroup00

Volume group "VolGroup00" successfully created

[root@cimdb:~] vgdisplay 查看系统中的物理卷组信息

--- Volume group ---

VG Name VolGroup00

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 1024.00 MB

PE Size 4.00 MB

Total PE 255

Alloc PE / Size 0 / 0

Free PE / Size 255 / 1024.00 MB

VG UUID Ar3Ono-eb6V-6otn-SDm3-wqSR-4cif-1SS6nA

[root@cimdb:~] pvcreate /dev/sdc 将/dev/sdc 创建成一个物理卷

Writing physical volume data to disk "/dev/asm-diskd"

Physical volume "/dev/asm-diskd" successfully created

[root@cimdb:~] vgextend VolGroup00 /dev/sdc 对物理卷组进行扩展

Volume group "VolGroup00" successfully extended

[root@cimdb:~] pvcreate /dev/sdd 将/dev/sdd 创建成一个物理卷

Writing physical volume data to disk "/dev/asm-diskd"

Physical volume "/dev/asm-diskd" successfully created

[root@cimdb:~] vgextend VolGroup00 /dev/sdd 对物理卷组进行扩展

Volume group "VolGroup00" successfully extended

[root@cimdb:~] pvcreate /dev/sde 将/dev/sde 创建成一个物理卷

Writing physical volume data to disk "/dev/asm-diskf"

Physical volume "/dev/asm-diskf" successfully created

[root@cimdb:~] vgextend VolGroup00 /dev/sde 对物理卷组进行扩展

Volume group "VolGroup00" successfully extended

[root@cimdb:~] pvcreate /dev/sdf 将/dev/sdf 创建成一个物理卷

Writing physical volume data to disk "/dev/asm-diskf"

Physical volume "/dev/asm-diskf" successfully created

[root@cimdb:~] vgextend VolGroup00 /dev/sdf 对物理卷组进行扩展

Volume group "VolGroup00" successfully extended

[root@cimdb:~] vgdisplay

--- Volume group ---

VG Name VolGroup00

System ID

Format lvm2

Metadata Areas 7

Metadata Sequence No 7

VG Access read/write

VG Status resizable

MAX LV 0

Cur LV 0

Open LV 0

Max PV 0

Cur PV 7

Act PV 7

VG Size 15.00 GB

PE Size 4.00 MB

Total PE 7929

Alloc PE / Size 0 / 0

Free PE / Size 7929 / 15.00 GB

VG UUID Ar3Ono-eb6V-6otn-SDm3-wqSR-4cif-1SS6nA

[root@cimdb:~] lvcreate -L 15G -n Logvol00 VolGroup00 从物理卷组VolGroup00中分配15G的容量来创建一个逻辑卷，供系统使用

Logical volume "Logvol00" created

[root@cimdb:~] lvdisplay 查看逻辑卷的信息

--- Logical volume ---

LV Name /dev/VolGroup00/Logvol00

VG Name VolGroup00

LV UUID JxbpLG-dK3A-EvzE-cJOP-mpoD-OXEf-8cEwDq

LV Write Access read/write

LV Status available

# open 0

LV Size 15.00 GB

Current LE 7680

Segments 7

Allocation inherit

Read ahead sectors auto

- currently set to 256

Block device 253:0

[root@cimdb:/dev/VolGroup00] mkfs.ext2 /dev/VolGroup00/Logvol00 使用mkfs.ext来格式化逻辑卷

mke2fs 1.39 (29-May-2006)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

3932160 inodes, 7864320 blocks

393216 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

240 block groups

32768 blocks per group, 32768 fragments per group

16384 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000

Writing inode tables: done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 24 mounts or

180 days, whichever comes first. Use tune2fs -c or -i to override.

[root@cimdb:/] mount /dev/mapper/VolGroup00-Logvol00 /u01 将刚才添加的逻辑卷挂载在/u01目录下，供系统调用

[root@cimdb:/] df -h

Filesystem Size Used Avail Use% Mounted on

/dev/sda1 5.9G 3.6G 2.0G 66% /

/dev/sda6 2.0G 36M 1.9G 2% /tmp

/dev/sda3 9.7G 1.2G 8.0G 13% /home

/dev/sda2 30G 26G 1.8G 94% /oracle

tmpfs 3.9G 0 3.9G 0% /dev/shm

/dev/mapper/VolGroup00-Logvol00 15G 44M 28G 1% /u01 ---已经挂载OK

============================================================================================================

卸载之前挂载的目录：

[root@cimdb:/] umount -l /u01