前言
传统的老牌的分区工具是fdisk，但是fdisk出道太早，只支持MBR（Master Boot Record），并不支持GPT（GUID Partition Table），无法操作超过2T的磁盘，因此gdisk parted等分区工具横空出世。
gdisk和parted都曾经用过，但是我更喜欢gdisk，因为使用上，gdisk 上承fdisk，没有太多的学习负担。另外我们QA测出过，parted方式分区，在某些使用上会有问题。
使用方法
首先，我有一个sdd，作为我操作的对象。
root@node3:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 4K 0 disk
sda 8:0 0 40G 0 disk
├─sda1 8:1 0 30.5M 0 part
├─sda2 8:2 0 488.3M 0 part
├─sda3 8:3 0 31.1G 0 part /
├─sda4 8:4 0 8G 0 part [SWAP]
└─sda5 8:5 0 387.8M 0 part
sdb 8:16 0 50G 0 disk
├─sdb1 8:17 0 4G 0 part
└─sdb2 8:18 0 46G 0 part /data/osd.4
sdc 8:32 0 50G 0 disk
├─sdc1 8:33 0 4G 0 part
└─sdc2 8:34 0 46G 0 part /data/osd.5
sdd 8:48 0 50G 0 disk
sr0 11:0 1 1.6G 0 rom
查看help信息
进入交互模式之后，输入h可以查看帮助信息
root@node3:~# gdisk /dev/sdd
GPT fdisk (gdisk) version 0.8.1
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Command (? for help): h
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):
查看分区表信息
很明显，做出没有分区，所以分区表为空,后面创建分区之后，可以通过p命令查看分区信息
Command (? for help): p
Disk /dev/sdd: 104857600 sectors, 50.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D3328858-7A3F-4A64-BC46-A7040F306F33
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 104857566
Partitions will be aligned on 2048-sector boundaries
Total free space is 104857533 sectors (50.0 GiB)
Number Start (sector) End (sector) Size Code Name
Command (? for help):
创建分区
打算将50G的空间划分成2个分区，分别是10G和40G： 创建分区是用命令n，你需要选择
- 分区number
- 起始扇区
- 结束扇区
起始扇区可以敲回车选择默认值，而结束扇区用＋10G这种方式来决定分区大小为10G 分区后，可以用p命令查看最新的分区表
Command (? for help): n
Partition number (1-128, default 1): 1
First sector (34-104857566, default = 34) or {+-}size{KMGTP}:
Information: Moved requested sector from 34 to 2048 in
order to align on 2048-sector boundaries.
Use 'l' on the experts' menu to adjust alignment
Last sector (2048-104857566, default = 104857566) or {+-}size{KMGTP}: +10G
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): p
Disk /dev/sdd: 104857600 sectors, 50.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D3328858-7A3F-4A64-BC46-A7040F306F33
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 104857566
Partitions will be aligned on 2048-sector boundaries
Total free space is 83886013 sectors (40.0 GiB)
Number Start (sector) End (sector) Size Code Name
1 2048 20973567 10.0 GiB 8300 Linux filesystem
Command (? for help): n
Partition number (2-128, default 2): 2
First sector (34-104857566, default = 20973568) or {+-}size{KMGTP}:
Last sector (20973568-104857566, default = 104857566) 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): p
Disk /dev/sdd: 104857600 sectors, 50.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D3328858-7A3F-4A64-BC46-A7040F306F33
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 104857566
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number Start (sector) End (sector) Size Code Name
1 2048 20973567 10.0 GiB 8300 Linux filesystem
2 20973568 104857566 40.0 GiB 8300 Linux filesystem
Command (? for help):
设置分区标签信息partlabel
有些时候，磁盘的盘符会漂移，使用sdx这种方式来分辨磁盘是不靠谱，使用lable这种方式是可靠的。那么如何创建分区标签呢？
c是用来设置partlable的
Command (? for help): c
Partition number (1-2): 1
Enter name: bean_part1
Command (? for help): c
Partition number (1-2): 2
Enter name: bean_part2
Command (? for help): p
Disk /dev/sdd: 104857600 sectors, 50.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D3328858-7A3F-4A64-BC46-A7040F306F33
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 104857566
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)
Number Start (sector) End (sector) Size Code Name
1 2048 20973567 10.0 GiB 8300 bean_part1
2 20973568 104857566 40.0 GiB 8300 bean_part2
保存分区信息
我们将磁盘分成了2个区，给每一个分区贴上了partlabel，但是退出gdisk之前必须保存，否则前功尽弃。
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).
The operation has completed successfully.
root@node3:~#
效果
愉快地查看分区效果吧：
root@node3:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
fd0 2:0 1 4K 0 disk
sda 8:0 0 40G 0 disk
├─sda1 8:1 0 30.5M 0 part
├─sda2 8:2 0 488.3M 0 part
├─sda3 8:3 0 31.1G 0 part /
├─sda4 8:4 0 8G 0 part [SWAP]
└─sda5 8:5 0 387.8M 0 part
sdb 8:16 0 50G 0 disk
├─sdb1 8:17 0 4G 0 part
└─sdb2 8:18 0 46G 0 part /data/osd.4
sdc 8:32 0 50G 0 disk
├─sdc1 8:33 0 4G 0 part
└─sdc2 8:34 0 46G 0 part /data/osd.5
sdd 8:48 0 50G 0 disk
├─sdd1 8:49 0 10G 0 part
└─sdd2 8:50 0 40G 0 part
sr0 11:0 1 1.6G 0 rom
root@node3:~# ll /dev/disk/by-partlabel/
total 0
drwxr-xr-x 2 root root 180 Apr 1 22:23 ./
drwxr-xr-x 9 root root 180 Apr 1 21:34 ../
lrwxrwxrwx 1 root root 10 Apr 1 22:23 bean_part1 -> ../../sdd1
lrwxrwxrwx 1 root root 10 Apr 1 22:23 bean_part2 -> ../../sdd2
...