Linux 基本命令（七）
阿新 • • 發佈：2018-11-03
1、磁碟分割槽
Linux系統預設所有裝置檔案都在/dev下面
/dev/sda --硬碟1 sda1 第一個分割槽 sda2 第二個分割槽 sda3 第三個分割槽
[[email protected] dev]# ll |grep 'sd' lrwxrwxrwx. 1 root root 4 Sep 30 22:49 root -> sda3 brw-rw----. 1 root disk 8, 0 Sep 30 22:49 sda brw-rw----. 1 root disk 8, 1 Sep 30 22:49 sda1 brw-rw----. 1 root disk 8, 2 Sep 30 22:49 sda2 brw-rw----. 1 root disk 8, 3 Sep 30 22:49 sda3
/dev/sdb --硬碟2 sdb1 第一個分割槽 sdb2 第二個分割槽 sdb3 第三個分割槽
/dev/sdc --硬碟3
2、# fdisk -l 檢視系統所有硬碟的分割槽情況
（1）系統一共有幾塊硬碟，每個硬碟的容量大小
（2）每個硬碟的分割槽情況（硬碟空間是否還有剩餘）
[[email protected] dev]# fdisk -l Disk /dev/sda: 42.9 GB, 42949672960 bytes 255 heads, 63 sectors/track, 5221 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0009d896 Device Boot Start End Blocks Id System /dev/sda1 * 1 39 307200 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 39 543 4046848 82 Linux swap / Solaris Partition 2 does not end on cylinder boundary. /dev/sda3 543 5222 37587968 83 Linux
3、新增硬碟，先關機後新增
[[email protected] ~]# fdisk -l Disk /dev/sda: 42.9 GB, 42949672960 bytes 255 heads, 63 sectors/track, 5221 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0009d896 Device Boot Start End Blocks Id System /dev/sda1 * 1 39 307200 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 39 543 4046848 82 Linux swap / Solaris Partition 2 does not end on cylinder boundary. /dev/sda3 543 5222 37587968 83 Linux Disk /dev/sdb: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000
4、分割槽操作
分割槽步驟：
（1） fdisk 裝置名稱（/dev/sdb）
（2）partx -a /dev/sdb 使系統重新識別分割槽
（3）mkfs.ext4 /dev/sdb6 格式化 分割槽完必須要格式化後才能用哈
（4）# mount /dev/sdb5 /mnt 掛載 （臨時生效）
永久生效需要就修改/etc/fstab （例如：將 /dev/sdb5 /wwwroot ext4 defaults 0 0 按列填寫至後面）
檔案系統：ext2 ext3 ext4 xfs (如windows有NTFS)
block:
--Linux 作業系統管理檔案的最小（邏輯）單位
--大小有1k 2k 4k
[[email protected] dev]# mkfs.ext4 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
348816 inodes, 1393630 blocks
69681 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1430257664
43 block groups如用ext4下block大小為4k，如果一個檔案是1k，會用一個block儲存它，剩餘3k會浪費掉。
注：記住哈，hadoop中還會見面的。
----------------------------------------------------------------------------分割槽步驟---------------------------------------------------------------------------------
新增分割槽：
[[email protected] dev]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xd2d759dc.
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)
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 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)
p
Partition number (1-4): 1
First cylinder (1-2610, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-2610, default 2610): +15G
Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2d759dc
Device Boot Start End Blocks Id System
/dev/sdb1 1 1959 15735636 83 Linux
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 2
First cylinder (1960-2610, default 1960):
Using default value 1960
Last cylinder, +cylinders or +size{K,M,G} (1960-2610, default 2610):
Using default value 2610
Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2d759dc
Device Boot Start End Blocks Id System
/dev/sdb1 1 1959 15735636 83 Linux
/dev/sdb2 1960 2610 5229157+ 5 Extended再分擴充套件分割槽為邏輯分割槽：
Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2d759dc
Device Boot Start End Blocks Id System
/dev/sdb1 1 1959 15735636 83 Linux
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 2
First cylinder (1960-2610, default 1960):
Using default value 1960
Last cylinder, +cylinders or +size{K,M,G} (1960-2610, default 2610):
Using default value 2610
Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2d759dc
Device Boot Start End Blocks Id System
/dev/sdb1 1 1959 15735636 83 Linux
/dev/sdb2 1960 2610 5229157+ 5 Extended
Command (m for help): m^H
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^H
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (1960-2610, default 1960):
Using default value 1960
Last cylinder, +cylinders or +size{K,M,G} (1960-2610, default 2610): 2500
Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xd2d759dc
Device Boot Start End Blocks Id System
/dev/sdb1 1 1959 15735636 83 Linux
/dev/sdb2 1960 2610 5229157+ 5 Extended
/dev/sdb5 1960 2500 4345551 83 Linux
寫入退出儲存：
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): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[[email protected] dev]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0009d896
Device Boot Start End Blocks Id System
/dev/sda1 * 1 39 307200 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 39 543 4046848 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 543 5222 37587968 83 Linux
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0a4a3d6d
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10490413+ 83 Linux
/dev/sdb2 1307 2610 10474380 5 Extended
/dev/sdb5 1307 2000 5574523+ 83 Linux
格式化：
[[email protected] dev]# mkfs.ext4 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
348816 inodes, 1393630 blocks
69681 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1430257664
43 block groups
32768 blocks per group, 32768 fragments per group
8112 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 22 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[email protected] dev]# mkfs.ext4 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655776 inodes, 2622603 blocks
131130 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2688548864
81 block groups
32768 blocks per group, 32768 fragments per group
8096 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[email protected] dev]# mkfs.ext4 /dev/sdb2
mke2fs 1.41.12 (17-May-2010)
mkfs.ext4: inode_size (128) * inodes_count (0) too big for a
filesystem with 0 blocks, specify higher inode_ratio (-i)
or lower inode count (-N).
掛載：
[[email protected] dev]# mount /dev/sdb5 /mnt
[[email protected] dev]# cd /mnt
[[email protected] mnt]# ls
lost+found
[[email protected] mnt]# cd lost+found/
[[email protected] lost+found]# ls
[[email protected] lost+found]# cd ..
[[email protected] mnt]# cd ..
[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 36G 3.5G 30G 11% /
tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 283M 65M 204M 25% /boot
/dev/sdb5 5.2G 11M 4.9G 1% /mnt
解除安裝-->裝載：
[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 36G 3.5G 30G 11% /
tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 283M 65M 204M 25% /boot
/dev/sdb5 5.2G 11M 4.9G 1% /mnt
[[email protected] /]# umount /mnt
[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 36G 3.5G 30G 11% /
tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 283M 65M 204M 25% /boot
[[email protected] /]# mkdir /wwwroot
[[email protected] /]# mount /dev/sdb5 /wwwroot
[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 36G 3.5G 30G 11% /
tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 283M 65M 204M 25% /boot
/dev/sdb5 5.2G 11M 4.9G 1% /wwwroot
[[email protected] /]# mount /dev/sdb1 /mnt
[[email protected] /]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 36G 3.5G 30G 11% /
tmpfs 1.9G 72K 1.9G 1% /dev/shm
/dev/sda1 283M 65M 204M 25% /boot
/dev/sdb5 5.2G 11M 4.9G 1% /wwwroot
/dev/sdb1 9.8G 23M 9.3G 1% /mnt
目錄是分割槽的訪問入口，如果在目錄下建立檔案後解除安裝分割槽，目錄下的檔案就不存在了哈，不信可以試試~~~