用gdisk调整gpt/ext4分区大小

主机： CentOS release 6.4 (Final)

目的：从/home分区分出100G来创建新分区/vm

参考：

http://ryanclouser.com/?p=66

http://falstaff.agner.ch/2013/12/22/online-resize-root-filesystem-on-a-gpt-partition/

http://blog.zepsikopat.net/2011/07/22/resize-an-ext4-partition-on-a-gpt-disk/

http://superuser.com/questions/660309/live-resize-of-a-gpt-partition-on-linux

1. 查看当前分区情况

[root@tanghuimin
/]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/sda3 ext4 9.7G 6.6G 2.6G 72% /

tmpfs tmpfs 1.8G 280K 1.8G 1% /dev/shm

/dev/sda1 ext4 426G 37G 368G 10% /home

/dev/sda2 ext4 20G 4.2G 15G 23% /opt

/home分区在/dev/sda1.

2. gdisk /dev/sda

?: 打印gdisk下命令的用法

p: 查看分区表

b:
备份分区表，以便后面操作失误可以恢复分区表

[root@tanghuimin
~]# gdisk /dev/sda

GPT fdisk (gdisk) version 0.8.10

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: present

Found valid GPT with protective MBR; using GPT.

Command (?
for help): ?

b back up GPT data to a file

c change a partition's name

d delete a partition

i show detailed information on a partition

l list known partition types

n add a new partition

o create a new empty GUID partition table (GPT)

p print the partition table

q quit without saving changes

r recovery and transformation options (experts only)

s sort partitions

t change a partition's type code

v verify disk

w write table to disk and exit

x extra functionality (experts only)

? print this menu

Command (?
for help): p

Disk /dev/sda: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): FB42D8BC-9B54-4B3B-A16C-A39A39B902FF

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 976773134

Partitions will be aligned on 2048-sector boundaries

Total free space is 2029 sectors (1014.5 KiB)

Number Start (sector) End (sector) Size Code Name

1 2048 907141119 432.6 GiB 0700

2 907141120 948101119 19.5 GiB 0700

3 948101120 968581119 9.8 GiB EF00

4 968581120 976773119 3.9 GiB 8200

Command (?
for help): b

Enter backup filename to save: /root/gpt.sda.bak

The operation has completed successfully.

3. 卸载即将被调整的分区/home

[root@tanghuimin
~]# umount /home/

[root@tanghuimin ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/sda3 ext4 9.7G 6.6G 2.6G 72% /

tmpfs tmpfs 1.8G 296K 1.8G 1% /dev/shm

/dev/sda2 ext4 20G 4.2G 15G 23% /opt

4. 检测文件系统错误

[root@tanghuimin
~]# e2fsck -f /dev/sda1

e2fsck 1.41.12 (17-May-2010)

Pass 1: Checking inodes, blocks, and sizes

Pass 2: Checking directory structure

Pass 3: Checking directory connectivity

Pass 4: Checking reference counts

Pass 5: Checking group summary information

/dev/sda1: 268432/28352512 files (0.1% non-contiguous),
11359488/113392384 blocks

5. 用resize2fs调整文件系统大小

[root@tanghuimin
~]# resize2fs /dev/sda1 326G

resize2fs 1.41.12 (17-May-2010)

Resizing the filesystem on /dev/sda1 to 85458944 (4k) blocks.

The filesystem on /dev/sda1 is now 85458944 blocks long.

6. 用gdisk调整分区大小，先用d删除分区，后用n创建分区

[root@tanghuimin ~]# gdisk /dev/sda

GPT fdisk (gdisk) version 0.8.10

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p

Disk /dev/sda: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): FB42D8BC-9B54-4B3B-A16C-A39A39B902FF

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 976773134

Partitions will be aligned on 2048-sector boundaries

Total free space is 2029 sectors (1014.5 KiB)

Number Start (sector) End (sector) Size Code Name

1 2048 907141119 432.6 GiB 0700

2 907141120 948101119 19.5 GiB 0700

3 948101120 968581119 9.8 GiB EF00

4 968581120 976773119 3.9 GiB 8200

Command (?
for help): d

Partition number (1-4): 1

Command (? for help): p

Disk /dev/sda: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): FB42D8BC-9B54-4B3B-A16C-A39A39B902FF

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 976773134

Partitions will be aligned on 2048-sector boundaries

Total free space is 907141101 sectors (432.6 GiB)

Number Start (sector) End (sector) Size Code Name

2 907141120 948101119 19.5 GiB 0700

3 948101120 968581119 9.8 GiB EF00

4 968581120 976773119 3.9 GiB 8200

Command (?
for help): n

Partition number (1-128, default 1):

First sector (34-976773134, default = 2048) or {+-}size{KMGTP}:

Last sector (2048-907141119, default = 907141119) or
{+-}size{KMGTP}: 326G

Current type is 'Linux filesystem'

Hex code or GUID (L to show codes, Enter = 8300):

Changed type of partition to 'Linux filesystem'

Command
(? for help): w

Final checks complete. About to write GPT data. THIS WILL
OVERWRITE EXISTING

PARTITIONS!!

Do you want to proceed? (Y/N): y

OK; writing new GUID partition table (GPT) to /dev/sda.

Warning: The kernel is still using the old partition table.

The new table will be used at the next reboot.

The operation has completed successfully.

分区大小调整完毕。

7. 将/dev/sda1挂载到/home

[root@tanghuimin ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/sda3 ext4 9.7G 6.6G 2.6G 72% /

tmpfs tmpfs 1.8G 296K 1.8G 1% /dev/shm

/dev/sda2 ext4 20G 4.2G 15G 23% /opt

[root@tanghuimin
~]# mount /dev/sda1 /home/

[root@tanghuimin ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/sda3 ext4 9.7G 6.6G 2.6G 72% /

tmpfs tmpfs 1.8G 296K 1.8G 1% /dev/shm

/dev/sda2 ext4 20G 4.2G 15G 23% /opt

/dev/sda1 ext4 321G 37G 269G 12% /home

reboot.

8. 在/dev/sda所有free的空间上创建新分区

[root@tanghuimin ~]# gdisk /dev/sda

GPT fdisk (gdisk) version 0.8.10

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p

Disk /dev/sda: 976773168 sectors, 465.8 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): FB42D8BC-9B54-4B3B-A16C-A39A39B902FF

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 976773134

Partitions will be aligned on 2048-sector boundaries

Total free space is 221374444 sectors (105.6 GiB)

Number Start (sector) End (sector) Size Code Name

1 2048 685768704 327.0 GiB 8300 Linux
filesystem

2 907141120 948101119 19.5 GiB 0700

3 948101120 968581119 9.8 GiB EF00

4 968581120 976773119 3.9 GiB 8200

Command (?
for help): n

Partition number (5-128, default 5):

First sector (34-976773134, default = 685770752) or
{+-}size{KMGTP}:

Last sector (685770752-907141119, default = 907141119) or
{+-}size{KMGTP}:

Current type is 'Linux filesystem'

Hex code or GUID (L to show codes, Enter = 8300):

Changed type of partition to 'Linux filesystem'

Command (?
for help): w

Final checks complete. About to write GPT data. THIS WILL
OVERWRITE EXISTING

PARTITIONS!!

Do you want to proceed? (Y/N): y

OK; writing new GUID partition table (GPT) to /dev/sda.

Warning: The kernel is still using the old partition table.

The new table will be used at the next reboot.

The operation has completed successfully.

9. 将新分区的文件系统类型设为ext4

[root@tanghuimin
~]# mkfs -t ext4 /dev/sda5

mke2fs 1.41.12 (17-May-2010)

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=1 blocks, Stripe width=0 blocks

6922240 inodes, 27671296 blocks

1383564 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

845 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,
2654208,

4096000, 7962624, 11239424, 20480000, 23887872

Writing inode tables: done

Creating journal (32768 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 33 mounts
or

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

10. 将新分区/dev/sda5挂载到/vm

[root@tanghuimin
~]# mount /dev/sda5 /vm

[root@tanghuimin ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/sda3 ext4 9.7G 6.6G 2.6G 72% /

tmpfs tmpfs 1.8G 224K 1.8G 1% /dev/shm

/dev/sda1 ext4 321G 37G 269G 12% /home

/dev/sda2 ext4 20G 4.2G 15G 23% /opt

/dev/sda5 ext4 104G 188M 99G 1% /vm

11.
在/etc/fstab中添加如下行，使在系统启动时/dev/sda5被挂载到/vm

/dev/sda5 /vm ext4 defaults 1
2

reboot.