查看磁盤使用情況和磁盤分區(qū)
fdisk命令 用于觀察硬盤實(shí)體使用情況，也可對(duì)硬盤分區(qū)。它采用傳統(tǒng)的問答式界面，而非類似DOS?fdisk的cfdisk互動(dòng)式操作界面，因此在使用上較為不便，但功能卻絲毫不打折扣。
fdisk(選項(xiàng))(參數(shù))
-b <大小> 扇區(qū)大小(512、1024、2048或4096)
-c[=<模式>] 兼容模式：“dos”或“nondos”(默認(rèn))
-h 打印此幫助文本
-u[=<單位>] 顯示單位：“cylinders”(柱面)或“sectors”(扇區(qū)，默認(rèn))
-v 打印程序版本
-C <數(shù)字> 指定柱面數(shù)
-H <數(shù)字> 指定磁頭數(shù)
-S <數(shù)字> 指定每個(gè)磁道的扇區(qū)數(shù)
設(shè)備文件：指定要進(jìn)行分區(qū)或者顯示分區(qū)的硬盤設(shè)備文件。
首先選擇要進(jìn)行操作的磁盤：
[root@localhost ~]# fdisk /dev/sdb
輸入m列出可以執(zhí)行的命令：
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)
輸入p列出磁盤目前的分區(qū)情況：
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1 8001 8e Linux LVM
/dev/sdb2 2 26 200812+ 83 Linux
輸入d然后選擇分區(qū)，刪除現(xiàn)有分區(qū)：
Command (m for help): d
Partition number (1-4): 1
Command (m for help): d
Selected partition 2
查看分區(qū)情況，確認(rèn)分區(qū)已經(jīng)刪除：
Command (m for help): print
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
Command (m for help):
輸入n建立新的磁盤分區(qū)，首先建立兩個(gè)主磁盤分區(qū)：
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p //建立主分區(qū)
Partition number (1-4): 1 //分區(qū)號(hào)
First cylinder (1-391, default 1): //分區(qū)起始位置
Using default value 1
last cylinder or +size or +sizeM or +sizeK (1-391, default 391): 100 //分區(qū)結(jié)束位置，單位為扇區(qū)
Command (m for help): n //再建立一個(gè)分區(qū)
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2 //分區(qū)號(hào)為2
First cylinder (101-391, default 101):
Using default value 101
Last cylinder or +size or +sizeM or +sizeK (101-391, default 391): +200M //分區(qū)結(jié)束位置，單位為M
確認(rèn)分區(qū)建立成功：
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218+ 83 Linux
/dev/sdb2 101 125 200812+ 83 Linux
再建立一個(gè)邏輯分區(qū)：
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e //選擇擴(kuò)展分區(qū)
Partition number (1-4): 3
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or +size or +sizeM or +sizeK (126-391, default 391):
Using default value 391
確認(rèn)擴(kuò)展分區(qū)建立成功：
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218+ 83 Linux
/dev/sdb2 101 125 200812+ 83 Linux
/dev/sdb3 126 391 2136645 5 Extended
在擴(kuò)展分區(qū)上建立兩個(gè)邏輯分區(qū)：
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l //選擇邏輯分區(qū)
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or +size or +sizeM or +sizeK (126-391, default 391): +400M
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (176-391, default 176):
Using default value 176
Last cylinder or +size or +sizeM or +sizeK (176-391, default 391):
Using default value 391
確認(rèn)邏輯分區(qū)建立成功：
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218+ 83 Linux
/dev/sdb2 101 125 200812+ 83 Linux
/dev/sdb3 126 391 2136645 5 Extended
/dev/sdb5 126 175 401593+ 83 Linux
/dev/sdb6 176 391 1734988+ 83 Linux
Command (m for help):
從上面的結(jié)果我們可以看到，在硬盤sdb我們建立了2個(gè)主分區(qū)（sdb1，sdb2），1個(gè)擴(kuò)展分區(qū)（sdb3），2個(gè)邏輯分區(qū)（sdb5，sdb6）
注意：主分區(qū)和擴(kuò)展分區(qū)的磁盤號(hào)位1-4，也就是說最多有4個(gè)主分區(qū)或者擴(kuò)展分區(qū)，邏輯分區(qū)開始的磁盤號(hào)為5，因此在這個(gè)實(shí)驗(yàn)中試沒有sdb4的。
最后對(duì)分區(qū)操作進(jìn)行保存：
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
建立好分區(qū)之后我們還需要對(duì)分區(qū)進(jìn)行格式化才能在系統(tǒng)中使用磁盤。
在sdb1上建立ext2分區(qū)：
[root@localhost ~]# mkfs.ext2 /dev/sdb1
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
100576 inodes, 200804 blocks
10040 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=209715200
7 block groups
32768 blocks per group, 32768 fragments per group
14368 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
在sdb6上建立ext3分區(qū)：
[root@localhost ~]# mkfs.ext3 /dev/sdb6
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
217280 inodes, 433747 blocks
21687 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=444596224
14 block groups
32768 blocks per group, 32768 fragments per group
15520 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
建立兩個(gè)目錄/oracle和/web，將新建好的兩個(gè)分區(qū)掛載到系統(tǒng)：
[root@localhost ~]# mkdir /oracle
[root@localhost ~]# mkdir /web
[root@localhost ~]# mount /dev/sdb1 /oracle
[root@localhost ~]# mount /dev/sdb6 /web
查看分區(qū)掛載情況：
[root@localhost ~]# df -h
文件系統(tǒng) 容量 已用 可用 已用% 掛載點(diǎn)
/dev/mapper/VolGroup00-LogVol00
6.7G 2.8G 3.6G 44% /
/dev/sda1 99M 12M 82M 13% /boot
tmpfs 125M 0 125M 0% /dev/shm
/dev/sdb1 773M 808K 733M 1% /oracle
/dev/sdb6 1.7G 35M 1.6G 3% /web
如果需要每次開機(jī)自動(dòng)掛載則需要修改/etc/fstab文件，加入兩行配置：
[root@localhost ~]# vim /etc/fstab
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
/dev/sdb1 /oracle ext2 defaults 0 0
/dev/sdb6 /web ext3 defaults 0 0