磁盤分區格式說明
linux分區不同於windows
linux下分區標示:
例如:hda1
hd這兩個字母表示分區所在的設備類型,hd標示IDE類型硬盤,sd表示SCSI類型硬盤
第三字母a標示硬盤在哪個接口
linux下硬盤設備名為(IDE硬盤為hdx(x為從a—d)因為IDE硬盤最多四個,SCSI,SATA,USB硬盤為sdx(x為a—z)),硬盤主分區最多為4個,不用說大家也知道…..所以主分區從sdb1開始到sdb4,邏輯分區從sdb5開始,(邏輯分區永遠從sdb5開始…)設備名可以使用fdisk –l查看
格式化原理:
MBR:主引導扇區
主分區表:64bytes,最多只能分四個主分區,每個主分區的記錄(相關信息,比如分區大小,位置)在主分區表里占14bytes。
如果要建多於四個的分區,就要拿出一個主分區做為擴展分區,再在擴展分區里面進行其它的分區操作。在 建擴展分區的時候會建立一張對應的擴展分區表,它記錄了在這個擴展分區里的分區的相關信息;理論上它沒有分區數量的限制,在擴展分區內部的分區叫做邏輯分區,如上圖中的 /dev/hda5,/dev/hda6/,/dev/hda7
在分好區后,分區里面是空的,沒有任何東西。為了能讓OS識別,就必須要向分區里寫入相應格式的數據。比如windows的FAT32,NTFS;Linux的ext2,ext3,ext4(目前ext3格式的用的比較多,ext4還在實驗之中,在新的Fedora上使用的就是ext4的文件系統)。
Windows/dos常用的分區工具:fdisk/partition magic/diskpart
Linux下常用的分區工具:
fdisk/sfdisk:命令行工具,各種版本和環境都能使用,包含在軟件包util-linux中
diskdruid:圖形化分區工具,只能在安裝REDHAT系統時使用。
下面我們開始實驗:
環境/工具:Fedora 14/256M內存卡;fdisk
第一步:fdisk
[root@novice ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
[root@novice ~]# fdisk /dev/sdb
Command (m for help): #在輸入上面的命令后會出現左邊的提示,輸入m就會得到一個幫助菜單,如下:
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)
#help雖然是英文的,可都很簡單,在這里不再解釋。
#現在,我們正式開始分區的操作:
Command (m for help): n #新建分區
Command action
e extended
p primary partition (1-4)
#e/p分別對應擴展分區 /主分區;我們先分四個主分區,每個50M;然后再來增加主分區或擴展分區,看會出現怎樣的狀況,嘿嘿。
p #分區類型為主分區
Partition number (1-4, default 1): 1 #分區號,在這里我們依次選擇1、2、3、4
First sector (2048-496127, default 2048): #指定分區的起始扇區,一般默認,按enter鍵即可。
Last sector, +sectors or +size{K,M,G} (2048-496127, default 496127): +50M #指定分區的終止扇區,根據前面的提示我們可以做出相應的選擇+sectors 或 +size{K,M,G}
Command (m for help): p #用p打印出已建好的分區列表
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
#剩下的三個分區的建立操作同上
#分好四個主分區后的情況如下
Command (m for help): p
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 83 Linux
/dev/sdb3 206848 309247 51200 83 Linux
/dev/sdb4 309248 309298 25+ 83 Linux
#已經建好四個主分區啦,現在我們來看看如果再建主分區或是擴展分區的話會出現怎樣的情況:
Command (m for help): n
You must delete some partition and add an extended partition first
#看到了吧,不能再建分區啦!要再建分區的話必須刪除some分區,再新建一個擴展分區才行。
#現在,我們刪掉一個主分區,來新建擴展分區
Command (m for help): d #刪除分區
Partition number (1-4): 4 #選擇要刪除分區的分區號,我們選第四個
Command (m for help): p #打印,如下,四個分區變成了三個!
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 83 Linux
/dev/sdb3 206848 309247 51200 83 Linux
#新建一個擴展分區
#如果在沒有建滿三個主分的區的情況下建立擴展分區,相關選項會有些不同。
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Selected partition 4
First sector (309248-496127, default 309248): #enter,默認
Using default value 309248
Last sector, +sectors or +size{K,M,G} (309248-496127, default 496127): #enter,默認,使用剩余空間
Using default value 496127
Command (m for help): p
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 83 Linux
/dev/sdb3 206848 309247 51200 83 Linux
/dev/sdb4 309248 496127 93440 5 Extended
#接下來,我們在新建的擴展分區里再新建兩個邏輯分區,因為已經有了三個主分區,這里不會再顯示是建立邏輯分區還是主分區的提示!
Command (m for help): n
First sector (311296-496127, default 311296): #enter
Using default value 311296
Last sector, +sectors or +size{K,M,G} (311296-496127, default 496127): +50M
Command (m for help): n
First sector (415744-496127, default 415744): #enter
Using default value 415744
Last sector, +sectors or +size{K,M,G} (415744-496127, default 496127): #enter
Using default value 496127
Command (m for help): p
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 83 Linux
/dev/sdb3 206848 309247 51200 83 Linux
/dev/sdb4 309248 496127 93440 5 Extended
/dev/sdb5 311296 413695 51200 83 Linux
/dev/sdb6 415744 496127 40192 83 Linux
#上面的列表,就是我們今天分區的成果啦!接下來保存退出,重啟計算機,就可以進行下一步的mkfs操作啦!如果忘記了相關的操作命令,記得按m!!!
Command (m for help): w #保存
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
另:在建好分區后,我們還可以更改相關分區的文件系統類型
#如,我們要把第二個主分區改成Linux下的交換分區,操作如下
Command (m for help): t #更改文件系統類型
Partition number (1-6): 2 #選擇第二個分區
Hex code (type L to list codes): L #選擇要更改的文件系統編碼,可以按L來查看相關編碼信息。
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-
............
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
Hex code (type L to list codes): 82 #查找到linux swap的編碼為82
Changed system type of partition 2 to 82 (Linux swap / Solaris)
Command (m for help): p
..............
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 82 Linux swap / Solaris
/dev/sdb3 206848 309247 51200 83 Linux
/dev/sdb4 309248 496127 93440 5 Extended
/dev/sdb5 311296 413695 51200 83 Linux
/dev/sdb6 415744 496127 40192 83 Linux
#最后別忘了保存!如果你須要的話!
#擴展分區不能直接使用,邏輯分區只能建立在擴展分區上!
第二步:mkfs(mkfs時分區的格式最好與fdisk設定的分區格式一致,不然.......)
mkfs支持ext2 ext3 vfa msdos jfs reiserfs等文件系統。
用法1:mkfs -t <fstype> <partition>
例: mkfs -t ext3 /dev/sdb2
用法2:mkfs.<fstype> <partition>
例:mkfs,vfat /dev/sdb3
mke2fs支持ext2/ext3文件系統
用法:mke2fs [-j] <partition>
例:mke2fs -j /dev/sdb5
# 更多更具體的用法請參照相關命令的man手冊
下面,接着實驗:
例一
[root@novice ~]# mkfs -t ext3 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
12824 inodes, 51200 blocks
2560 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=52428800
7 block groups
8192 blocks per group, 8192 fragments per group
1832 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 34 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
例二:
[root@novice ~]# fdisk /dev/sdb
Command (m for help): t
Partition number (1-6): 6
Hex code (type L to list codes): 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
.........
Hex code (type L to list codes): 7
Changed system type of partition 6 to 7 (HPFS/NTFS)
Command (m for help): p
Disk /dev/sdb: 254 MB, 254017536 bytes
8 heads, 61 sectors/track, 1016 cylinders, total 496128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 2048 104447 51200 83 Linux
/dev/sdb2 104448 206847 51200 82 Linux swap / Solaris
/dev/sdb3 206848 309247 51200 83 Linux
/dev/sdb4 309248 496127 93440 5 Extended
/dev/sdb5 311296 413695 51200 83 Linux
/dev/sdb6 415744 496127 40192 7 HPFS/NTFS
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@novice ~]# mkfs.ntfs /dev/sdb6
Cluster size has been automatically set to 4096 bytes.
Initializing device with zeroes: 100% - Done.
Creating NTFS volume structures.
mkntfs completed successfully. Have a nice day.
第三部:掛載
掛載:mount
例:mount /dev/sdb1 /mnt /sdb1
卸載:umonut
例:umount /dev/sdb1
/etc/fstab:
可以把要掛載的分區寫入/etc/fstab,這樣在開機的時候就能自動掛載啦!
#關於mount/nmout具體用法請參照man手冊,/etc/fstab內的掛載格式,參數等在該文件內都有相關的說明。這里只做一個簡單的測試,不再累述!
[root@novice /]# cd /mnt
[root@novice mnt]# mkdir sdb
[root@novice mnt]# mount /dev/sdb1 /mnt/sdb
[root@novice mnt]# cd /mnt/sdb
[root@novice sdb]# echo "Hello! I am here" > test.txt
[root@novice sdb]# cat test.txt
Hello! I am here
[root@novice sdb]# cd ..
[root@novice mnt]# umount /dev/sdb1
[root@novice mnt]# cd /mnt/sdb
[root@novice sdb]# ls -l
total 0
#剛做的文件系統已經能正常使用啦!現在再來看看掛載沒有經過mkfs的分區,會怎樣!
[root@novice sdb]# mount /dev/sdb2 /mnt/sdb
mount: unknown filesystem type 'LVM2_member'
#不解釋了喔!