CentOS根分區擴容方法

標籤：linux伺服器   硬碟擴容   

作業環境：

[[email protected] ~]# uname -a

Linux linux 2.6.32-358.18.1.el6.x86_64#1 SMP Wed Aug 28 17:19:38 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

現狀分析：

系統有兩個硬碟，第一個硬碟107G,“/”分區空間當時分區時只給了7.7G過小，空間馬上占完。現在系統有第二個硬碟sdb大小為16GB，希望把sdb的所有空間加入到“/”分區中，是其空間容量從7.7GB變成7.7GB+16GB（約2.4GB）。（當然如果這裡只有一個硬碟sda,有很多空間尚未使用可以進行同樣的操作）

操作步驟如下：

第一步、查看本機現有分區情況

[[email protected] ~]# df -h

檔案系統容量已用可用已用%% 掛載點

/dev/mapper/VolGroup-lv_root

                    7.7G  7.1G 155M  98% /

tmpfs                3.9G  296K 3.9G  1% /dev/shm

/dev/sda1            485M  64M 396M  14% /boot

/dev/sda3              83G  350M  79G  1% /media

第二步、查看原生磁碟情況

[[email protected] ~]# fdisk -l

Disk /dev/sda: 107.4 GB, 107374182400 bytes

255 heads, 63 sectors/track, 13054cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x000dc0ad

Device Boot      Start        End      Blocks  Id  System

/dev/sda1  *          1          64      512000  83  Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2              64        2089  16264192  8e  Linux LVM

/dev/sda3            2090      13054  88076362+  83  Linux

Disk /dev/mapper/VolGroup-lv_root: 8325 MB,8325693440 bytes

255 heads, 63 sectors/track, 1012 cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap: 8325 MB,8325693440 bytes

255 heads, 63 sectors/track, 1012 cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x00000000

注意：此時還沒有在EXSI5.0中添加第二塊硬碟

[[email protected] ~]#

第三步、添加第二塊硬碟

查看此時系統磁碟情況

[email protected] ~]# fdisk -l

Disk /dev/sda: 107.4 GB, 107374182400 bytes

255 heads, 63 sectors/track, 13054cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x000dc0ad

Device Boot      Start        End      Blocks  Id  System

/dev/sda1  *          1          64      512000  83  Linux

Partition 1 does not end on cylinderboundary.

/dev/sda2              64        2089  16264192  8e  Linux LVM

/dev/sda3            2090      13054  88076362+  83  Linux

Disk /dev/sdb: 17.2 GB, 17179869184 bytes

255 heads, 63 sectors/track, 2088 cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_root: 8325 MB,8325693440 bytes

255 heads, 63 sectors/track, 1012 cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap: 8325 MB,8325693440 bytes

255 heads, 63 sectors/track, 1012 cylinders

Units = cylinders of 16065 * 512 = 8225280bytes

Sector size (logical/physical): 512 bytes /512 bytes

I/O size (minimum/optimal): 512 bytes / 512bytes

Disk identifier: 0x00000000

可以看到我們新添加的硬碟sdb

[[email protected] ~]#

第四步、對第二塊硬碟sdb進行分區

[[email protected] ~]# fdisk /dev/sdb

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

Building a new DOS disklabel with diskidentifier 0xfa4abbdc.

Changes will remain in memory only, untilyou decide to write them.

After that, of course, the previous contentwon‘t be recoverable.

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

WARNING: DOS-compatible mode is deprecated.It‘s strongly recommended to

      switch off the mode (command ‘c‘) and change display units to

      sectors (command ‘u‘).

Command (m for help): m

Command action

a  toggle a bootable flag

b  edit bsd disklabel

c  toggle the dos compatibilityflag

d  delete a partition

l  list known partition types

m  print this menu

n  add a new partition

o  create a new empty DOSpartition table

p  print the partition table

q  quit without saving changes

s  create a new empty Sundisklabel

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 (expertsonly)

Command (m for help): n

Command action

e  extended

p  primary partition (1-4)

p 

Partition number (1-4): 4

First cylinder (1-2088, default 1):

Using default value 1

Last cylinder, +cylinders or +size{K,M,G}(1-2088, default 2088):

Using default value 2088

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

說明：上面操作對sdb硬碟進行了分區操作，設為sdb4分區了（當然上面建立的主要磁碟分割可以為1-4中的任意一個，我這裡選擇的4）。

第五步、對建立立的sdb4分區進行格式

[[email protected] ~]# mkfs.ext4 /dev/sdb4

mke2fs 1.41.12 (17-May-2010)

檔案系統標籤=

作業系統:Linux

塊大小=4096 (log=2)

分塊大小=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

1048576 inodes, 4192957 blocks

209647 blocks (5.00%) reserved for thesuper user

第一個資料區塊=0

Maximum filesystem blocks=4294967296

128 block groups

32768 blocks per group, 32768 fragments pergroup

8192 inodes per group

Superblock backups stored on blocks:

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

      4096000

正在寫入inode表: 完成

Creating journal (32768 blocks): 完成

Writing superblocks and filesystemaccounting information: done完成

This filesystem will be automaticallychecked every 20 mounts or

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

說明：將sdb4分區格式化為ext4格式，因為CentOS安裝是系統的格式ext4，所以這裡要注意一下。

第六步、格式後的sdb4分區添加為物理卷

[[email protected] ~]# pvcreate /dev/sdb4

Physical volume "/dev/sdb4" successfully created

第七步、查看當前系統的物理卷（PV）情況

[[email protected] ~]# pvdisplay

---Physical volume ---

PVName /dev/sda2

VGName VolGroup

PVSize 15.51 GiB / not usable3.00 MiB

Allocatable yes (butfull)

PESize 4.00 MiB

Total PE 3970

Free PE 0

Allocated PE 3970

PVUUID Up77sG-sNKf-Ja0k-crBf-N0wz-a5hy-T6sVFh

"/dev/sdb4" is a new physical volume of "15.99 GiB"

---NEW Physical volume ---

PVName /dev/sdb4

VGName

PVSize 15.99 GiB

Allocatable NO

PESize 0

Total PE 0

Free PE 0

Allocated PE 0

PVUUID Gqnw7N-HooX-S2Nz-1NIZ-YpOe-g0jo-grG1rQ

說明：可以看到添加的新物理卷sdb4，大小都符合我們添加時的設定

第八步、查看當前卷組情況

[[email protected] ~]# vgdisplay

---Volume group ---

VGName VolGroup

System ID

Format lvm2

Metadata Areas 1

Metadata Sequence No 3

VGAccess read/write

VGStatus resizable

MAXLV 0

CurLV 2

Open LV 2

MaxPV 0

CurPV 1

ActPV 1

VGSize 15.51 GiB

PESize 4.00 MiB

Total PE 3970

Alloc PE / Size 3970 / 15.51GiB

Free PE / Size 0 / 0

VGUUID PPrifh-glzl-nnxX-YkBm-xJ1s-rgnw-d1WsJd

第九步、將分區sdb4轉換為擴充分區

[[email protected] ~]# vgextend VolGroup/dev/sdb4

Volume group "VolGroup" successfully extended

第十步、查看當前的邏輯卷

[[email protected] ~]# lvdisplay

---Logical volume ---

LVPath /dev/VolGroup/lv_root

LVName lv_root

VGName VolGroup

LVUUID dCIsej-0NWX-bVFe-bT6L-c4eY-oy4G-9lNBOC

LVWrite Access read/write

LVCreation host, time ,

LVStatus available

#open 1

LVSize 7.75 GiB

Current LE 1985

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:0

---Logical volume ---

LVPath /dev/VolGroup/lv_swap

LVName lv_swap

VGName VolGroup

LVUUID K5bxJo-2SmM-6NCU-mBJP-Qzp1-ZODH-nbLK0k

LVWrite Access read/write

LVCreation host, time ,

LVStatus available

#open 1

LVSize 7.75 GiB

Current LE 1985

Segments 1

Allocation inherit

Read ahead sectors auto

-currently set to 256

Block device 253:1

說明：這裡可以看到“/”根分區的路徑名稱為：/dev/VolGroup/lv_root

第十一步、查看擴充後的卷組情況

[[email protected] ~]# vgdisplay

---Volume group ---

VGName VolGroup

System ID

Format lvm2

Metadata Areas 2

Metadata Sequence No 4

VGAccess read/write

VGStatus resizable

MAXLV 0

CurLV 2

Open LV 2

MaxPV 0

CurPV 2

ActPV 2

VGSize 31.50 GiB

PESize 4.00 MiB

Total PE 8064

Alloc PE / Size 3970 / 15.51GiB

Free PE / Size 4094 / 15.99 GiB

VGUUID PPrifh-glzl-nnxX-YkBm-xJ1s-rgnw-d1WsJd

說明：擴充後的卷子情況，可以看出大小增加了16GB（與第八步中的對比）

第十二步、將新增的邏輯卷全部擴充到“/”分區中

[[email protected] ~]# lvextend -L +15.99G/dev/VolGroup/lv_root

Rounding size to boundary between physical extents: 15.99 GiB

Extending logical volume lv_root to 23.75 GiB

Logical volume lv_root successfully resized

說明：這裡sdb4總共有16G，所以把16BG全部添加給根分區。

第十三步、查看“/”根分區格式，並重新重新整理根分區的大小

[[email protected] ~]# e2fsck -f/dev/VolGroup/lv_root

e2fsck 1.41.12 (17-May-2010)

/dev/VolGroup/lv_root is mounted.

e2fsck: 無法繼續, 中止.

[[email protected] ~]# resize2fs /dev/VolGroup/lv_root

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/VolGroup/lv_root ismounted on /; on-line resizing required

old desc_blocks = 1, new_desc_blocks = 2

Performing an on-line resize of/dev/VolGroup/lv_root to 6224896 (4k) blocks.

The filesystem on /dev/VolGroup/lv_root isnow 6224896 blocks long.

說明：命令resize2fs即重新整理根分區“/dev/VolGroup/lv_root”的容量。

第十三步、查看重新整理後根分區的大小

[[email protected] ~]# df -h

檔案系統容量已用可用已用%% 掛載點

/dev/mapper/VolGroup-lv_root

24G 7.1G 16G 32% /

tmpfs 3.9G 144K 3.9G 1% /dev/shm

/dev/sda3 83G 350M 79G 1% /media/Lucene

說明：可以看到根分區的大小有7.7G變成了24G，重啟一下系統再來看情況。此時就可以繼續安裝軟體了，不會提示空間不足了。

CentOS根分區擴容方法