磁盘分类 磁盘分区 分区命令
磁盘介绍:
磁盘接口分为4类:IDE(并行接口,淘汰了)也叫ATA接口,SATA(Serial Advanced Technology Attachment),SCSI(并行)和FC光纤通道接口(高端服务器)
磁盘分类:分固态硬盘和机械硬盘
IDE磁盘:IDE接口, 淘汰了,机械硬盘
SSD磁盘: SATA串行接口 Solid State Drive 体型比普通机械磁盘小 为固态硬盘
SAS磁盘:结合了sata接口和scsi接口两点的优点, 接口比scsi小 为机械硬盘
SATA磁盘: SATA串行接口 为机械硬盘
价格上:SSD>SAS>SATA 1Tsata 1000块吧 ,SAS为2000吧,SSD为1万
企业普及程度:SAS>SATA>SSD
生产中服务品牌及使用磁盘场景:
DELL,HP,IBM(百度)
SAS硬盘: 15000转每分 300G,600G和1000G SAS是生产场景首先 用于线上
SATA硬盘 10000转以下 1T和2T 主要用于线下 1T1000块吧
SSD磁盘 用于线上高并发 小容量(因为SSD贵)
Boot Sector也就是硬盘的第一个扇区,它由MBR(Master Boot Record), DPT(Disk Partition Table) 和 Boot Record ID三部分组成。 MBR又称为主引导记录,占用Boot Sector的前446个字节(0~0x1BD),存放系统主引导程序(它负责从活动分区中装载并且运行系统引导程序)。 DPT即主分区表占用64个字节(0x1BE~0x1FD),记录磁盘的基本分区信息。主分区表分为四个分区项,每项16个字节,分别记录每个主分区的信息(因此最多可以有四个主分区)。 Boot Record ID即引导区标记占用两个字节(0x1FE~0x1FF),对于合法引导区,它等于0xaa55,这是判别引导区是否合法的标志)
由于这个 MBR 区块的容量有限,所以,当初设计的时候,就只有设计成 4 个分区纪录,这些分区记录就被称为 Primary ( 主分区 ) 及Extended ( 扩展分区 ) ,也就是说,一颗硬盘最多可以有 4 个 Primary + Extended 的扇区,其中,Extended 只能有一个,因此,你如果要分区成四块磁盘 分区的话,那么最多就是可以:
P + P + P + P
P + P + P + E
主分区:一块物理硬盘上可以被独立使用的一部分,一个硬盘最多可以有4个主分区。
扩展分区:为了突破一个物理硬盘只能有4个分区的限制,引入了扩展分区。扩展分区和主分区的地位相当,但是扩展分区本身不能被直接使用,然而可以被继续划分成多个逻辑分区。
逻辑分区:逻辑分区可以有任意多个,但是不能独立存在,多个连续的逻辑分区可做为一个扩展分区。一个硬盘只能有一个扩展分区。
总结:也就是说,在一个物理硬盘上主分区和扩展分区加在一起最多仍然只有4个。但是扩展分区可以继续被划分成逻辑分区,而对多数用户而言,其实主分区和逻辑分区在使用上是没什么区别的。这样就达到了一快硬盘几乎可以有无限个分区的目的。
生产分区方式:
1. /boot 100M足以,主要放置机器启动的引导文件,如内核等
2. /
3.swap 分区 它是虚拟内存,swap分区大小=1.5*物理内存 G,分8~16G即可。内存大于8~16 作用是在物理内存使用完后,来虚拟内存使用。但是运行速度比真正的要慢的多,最好加大内存条来解决物理内存不够的情况
分区命令 fdsk tune2fs partprobe mkfs mount 5大命令
注意:fdsk分区适用于小于2T的情况,大于2T用parted
fdsk -l:list partition table
tune2fs -c -l /dev/hda1 关闭强制检查挂载次数限制
partprobe:通知内核有磁盘添加
mkfs.ext4 /dev/sdb1格式化或者mkfs -t ext4 /dev/sdb1
mount命令
下面为交互式分区方法:
添加一块1G的scsi硬盘
[root@lzc ~]# fdisk -l /dev/sdb 查看
Disk /dev/sdb: 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
[root@lzc ~]# fdisk /dev/sdb执行分区开始
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x91d7e50d.
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 分给主分区100M
Partition number (1-4): 1
First cylinder (1-130, default 1): 1
Last cylinder, +cylinders or +size{K,M,G} (1-130, default 130): +100M
Command (m for help): p
Disk /dev/sdb: 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: 0x91d7e50d
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423+ 83 Linux
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e 扩展分区分2个逻辑分区
Partition number (1-4): 2
First cylinder (15-130, default 15): 15
Last cylinder, +cylinders or +size{K,M,G} (15-130, default 130): 130
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (15-130, default 15): 15
Last cylinder, +cylinders or +size{K,M,G} (15-130, default 130): +400M
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (67-130, default 67):
Using default value 67
Last cylinder, +cylinders or +size{K,M,G} (67-130, default 130):
Using default value 130
Command (m for help):p
Disk /dev/sdb: 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: 0x91d7e50d
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423+ 83 linux
/dev/sdb2 15 130 931770 5 Extended
/dev/sdb5 15 66 417658+ 83 Linux
/dev/sdb6 67 130 514048+ 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@lzc ~]# partprobe /dev/sdb 通知内核
[root@lzc ~]# echo $?
0
[root@lzc ~]# ll /dev/sd*
brw-rw---- 1 root disk 8, 0 Mar 26 13:33 /dev/sda
brw-rw---- 1 root disk 8, 1 Mar 26 13:33 /dev/sda1
brw-rw---- 1 root disk 8, 2 Mar 26 13:33 /dev/sda2
brw-rw---- 1 root disk 8, 3 Mar 26 13:33 /dev/sda3
brw-rw---- 1 root disk 8, 16 Mar 26 13:49 /dev/sdb
brw-rw---- 1 root disk 8, 17 Mar 26 13:49 /dev/sdb1
brw-rw---- 1 root disk 8, 18 Mar 26 13:49 /dev/sdb2
brw-rw---- 1 root disk 8, 21 Mar 26 13:49 /dev/sdb5
brw-rw---- 1 root disk 8, 22 Mar 26 13:49 /dev/sdb6
[root@lzc ~]# fdisk /dev/sdb
Command (m for help): t
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
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
Hex code (type L to list codes): 8e调整此分区支持LVM
Changed system type of partition 5 to 8e (Linux LVM)
Command (m for help): p
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423+ 83 Linux
/dev/sdb2 15 130 931770 5 Extended
/dev/sdb5 15 66 417658+ 8e Linux LVM
/dev/sdb6 67 130 514048+ 83 Linux
Command (m for help): q不保存
[root@lzc ~]# mkfs.ext4 /dev/sdb1格式化,给此分区分配blocks和inodes
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
28112 inodes, 112420 blocks
5621 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
14 block groups
8192 blocks per group, 8192 fragments per group
2008 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Writing inode tables: done
Creating journal (4096 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@lzc ~]# tune2fs -c -1 /dev/sdb1 来override
tune2fs 1.41.12 (17-May-2010)
Setting maximal mount count to -1
[root@lzc ~]# mount /dev/sdb1 /mnt 生产中将次写到/etc/fstab中
[root@lzc ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 7.2G 2.1G 4.8G 30% /
tmpfs 497M 0 497M 0% /dev/shm
/dev/sda1 194M 28M 156M 16% /boot
/dev/sdb1 107M 5.6M 96M 6% /mnt