柱面:每一個盤片相同的同心圓環組成的一個立體結構app
扇區:扇形區域ide
磁頭:讀取數據工具
磁盤在Linux上屬於文件ui
通常HD開頭(IDE接口的硬盤)或者SD(SATA接口的硬盤)開頭this
a、b、c標示第幾塊磁盤spa
通常都是sda、sdb等code
sda1表示第一塊硬盤的第一塊分區blog
磁盤的分區接口
主流的分區機制有MBR和GPTci
1:MBR:主引導記錄。一般應用在使用BIOS的PC上(蘋果機不是的),該機制會佔用磁盤的頭512個字節用來存放引導代碼和分區表和啓動標示55AA(其餘的BIOS不能引導)
缺點:支持的分區有限;只支持小於2T的硬盤(由於於尋址空間是32)
分區:
1:主分區最多4個,能夠直接使用
2:擴展分區,該擴展分區會佔用一個主分區位置,以後必須建立邏輯分區纔可使用
2:GPT分區機制(64位尋址空間)
GPT分區機制:必須支持UEFI硬件才能使用,必須64位
磁盤分區的工具
1:fdisk,應用普遍,甚至包括救援模式下的Linux,可是不支持GPT模式
分區試驗:
1:先在虛擬機中添加一塊硬盤
2:
[root@gechong ~]# ll /dev | grep sd brw-rw----. 1 root disk 8, 0 11月 5 16:15 sda brw-rw----. 1 root disk 8, 1 11月 5 16:15 sda1 brw-rw----. 1 root disk 8, 2 11月 5 16:15 sda2
[root@gechong ~]# 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: 0x000ee95c Device Boot Start End Blocks Id System /dev/sda1 * 1 64 512000 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 64 2611 20458496 8e Linux LVM Disk /dev/mapper/vg_gechong-lv_root: 17.7 GB, 17725128704 bytes 255 heads, 63 sectors/track, 2154 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
能夠看到有一塊磁盤sda,有兩個分區sda1和sda2
255 heads磁頭, 63 sectors/track扇區, 2610 cylinders柱面
Start起始柱面 End結束柱面
添加一塊磁盤後從新用fdisk -l命令查看:會顯示多了一塊磁盤
Disk /dev/sdb: 8589 MB, 8589934592 bytes 255 heads, 63 sectors/track, 1044 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
可是其下面並無分區,由於咱們還沒有分區,分完以後會顯示在該、塊硬盤的下面
[root@gechong ~]# 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 0xb8fdd7dd. 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)
進入交互式界面只需按照提示一步一步建立分區便可
n爲建立新的分區
w保存後退出,不然不會生效
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e爲擴展分區
p爲主分區
通常爲先創建主分區,以後創建擴展分區再在擴展分區上創建邏輯分區
注意:主分區ID爲1-4 邏輯分區必須大於等於5
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1044, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1044, default 1044): +2G
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4): 5
Value out of range.
Partition number (1-4): 3
First cylinder (263-1044, default 263):
Using default value 263
Last cylinder, +cylinders or +size{K,M,G} (263-1044, default 1044): +2G
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (263-524, default 263):
Using default value 263
Last cylinder, +cylinders or +size{K,M,G} (263-524, default 524): +2G
[root@gechong ~]# fdisk -l | grep sdb Disk /dev/sdb: 8589 MB, 8589934592 bytes /dev/sdb1 1 262 2104483+ 83 Linux /dev/sdb2 263 524 2104515 5 Extended /dev/sdb5 263 524 2104483+ 83 Linux
若是沒有顯示,可使用partprobe命令更新內核後從新查看
[root@gechong ~]# cat /proc/partitions major minor #blocks name 8 0 20971520 sda 8 1 512000 sda1 8 2 20458496 sda2 8 16 8388608 sdb 8 17 2104483 sdb1 8 18 1 sdb2 8 21 2104483 sdb5 252 0 17309696 dm-0 252 1 3145728 dm-1
或者
[root@gechong ~]# ll /dev/sd* brw-rw----. 1 root disk 8, 0 11月 5 16:59 /dev/sda brw-rw----. 1 root disk 8, 1 11月 5 16:40 /dev/sda1 brw-rw----. 1 root disk 8, 2 11月 5 16:40 /dev/sda2 brw-rw----. 1 root disk 8, 16 11月 5 16:59 /dev/sdb brw-rw----. 1 root disk 8, 17 11月 5 16:59 /dev/sdb1 brw-rw----. 1 root disk 8, 18 11月 5 16:59 /dev/sdb2 brw-rw----. 1 root disk 8, 21 11月 5 16:59 /dev/sdb5