一、首先我们要知道磁盘为什么要分区,一块磁盘一个分区也可以的啊。
1.优化分区可提升磁盘I/O性能
2.可以对分区进行配置磁盘配额,便于磁盘资源的合理化利用
3.提高文件系统的修复速度
4.有效的隔离系统与应用程序,使得程序运行在与系统不同的分区
5.可以在不同的分区上安装不同的操作系统
6.在不同的分区上格式化为不同文件系统
二、那磁盘接口有哪些:
IDE SCSI SATA SAS 等
三、这些不同接口的设备在linux中的名称又是什么?
设备文件的命名一般格式:/dev/DEV_FILE
IDE: /dev/hd (centos6,7不在区分hd和sd统称为sd)
SCSI, SATA, SAS, USB: /dev/sd
四、分区有两个命令,此博客介绍fdisk,parted参考http://blog.51cto.com/12107790/2173127
五、man fdisk查看技术文档:
fdisk - Partition table manipulator for Linux 分区命令,其中描述信息介绍,此命令只能分区小于2T的磁盘,大于2T的磁盘使用parted命令来分区。
如果需要增加SWAP分区,需要使用mkswap命令+分区,使用swapon使swap分区生效,swapoff使分区失效。(注:常用于java进程占满内存时,临时加SWAP,让开发处理。)
常用选项:
-l [设备名称]:有设备名称时会列出分区的内容,若无则列出整个文件系统的所有分区列出
[root@www ~]# fdisk -l
Disk /dev/sda: 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: 0x000d7449
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 1301 10240000 83 Linux
/dev/sda3 1301 1556 2048000 82 Linux swap / Solaris
/dev/sda4 1556 2611 8477696 5 Extended
/dev/sda5 1556 2611 8476672 83 Linux
Disk /dev/sdd: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 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
分区步骤,使用/dev/sdd
[root@www ~]# fdisk /dev/sdd
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xdcb315ff.
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 删除一个分区
l list known partition types 列出磁盘分区类型代码
m print this menu
n add a new partition 新添一个分区
o create a new empty DOS partition table
p print the partition table 打印分区信息
q quit without saving changes 离开不保存
s create a new empty Sun disklabel
t change a partition's system id 修改分区类型代码,可用户创建swap分区
u change display/entry units
v verify the partition table
w write table to disk and exit 保存后离开
x extra functionality (experts only)
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p 添加主分区
Partition number (1-4): 1
First cylinder (1-130, default 1): 1
Last cylinder, +cylinders or +size{K,M,G} (1-130, default 130): 50
Command (m for help): p
Disk /dev/sdd: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 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: 0xdcb315ff
Device Boot Start End Blocks Id System
/dev/sdd1 1 50 401593+ 83 Linux
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e添加扩展分区
Partition number (1-4): 2
First cylinder (51-130, default 51):
Using default value 51
Last cylinder, +cylinders or +size{K,M,G} (51-130, default 130):
Using default value 130
Command (m for help): p
Disk /dev/sdd: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 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: 0xdcb315ff
Device Boot Start End Blocks Id System
/dev/sdd1 1 50 401593+ 83 Linux
/dev/sdd2 51 130 642600 5 Extended
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l 添加逻辑分区
First cylinder (51-130, default 51):
Using default value 51
Last cylinder, +cylinders or +size{K,M,G} (51-130, default 130): 80
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l继续添加逻辑分区
First cylinder (81-130, default 81):
Using default value 81
Last cylinder, +cylinders or +size{K,M,G} (81-130, default 130):
Using default value 130
Command (m for help): p
Disk /dev/sdd: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 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: 0xdcb315ff
Device Boot Start End Blocks Id System
/dev/sdd1 1 50 401593+ 83 Linux
/dev/sdd2 51 130 642600 5 Extended
/dev/sdd5 51 80 240943+ 83 Linux
/dev/sdd6 81 130 401593+ 83 Linux
Command (m for help): w 保存分区信息退出
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
列出查看分区类型代码:
Command (m for help): l
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1