linux系统创建主分区、逻辑分区 、设置ext系列分区的参数以及检测分区的方法

linux对不同的磁盘设备的设备文件命名如下：

        IDE： /dev/hd[a-z]
            对IDE分区的命名为/dev/hda1    /dev/hda2 …..
        SCSI, SATA, SAS, USB： /dev/sd[a-z]
            对分区的命令为/dev/sda1  /dev/sda2 …….
        主分区最多可有4个。若分区大于4个，可使用3个主分区加一个扩展分区的方式，再通过在扩展分区上划分多个逻辑分区。
        常见的文件格式有ext2、ext3、ext4、vfat(兼容windows的fat32)、xfs、btrfs、jfs等。

查看linux的磁盘分区可使用fdis（分区管理命令）

    fdisk /dev/sda (非IDE硬盘)
        m：获取帮助
        p：显示分区信息
        q：不保存退出
        n：新建分区
        d：删除分区
        q：保存退出
         l：显示分区类型的ID
         t：改变分区类型的ID

[root@localhost ~]# fdisk /dev/sda

Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/sda: 16.1 GB, 16106127360 bytes, 31457280 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 label type: dos
Disk identifier: 0x000a72d4
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048    20971519     9972736   8e  Linux LVM

说明：

    1、Disk /dev/sda: 16.1 GB 硬盘的大小是16GB，16106127360 个字节，31457280个扇区。
    2、下半部信息说明
        Device 是分区名称
        Boot 是否是启动分区
        Start 起始的扇区
        End 结束的扇区   \\  /dev/sda2结束的扇区是20971519，而硬盘总共有31457280，说明还有硬盘空间没有被用于创建分区。
        Blocks以1KB为单位，显示分区的空间；
        ld 为分区类型的ID号
        System 为分区类型

创建分区：（下图中指定起始扇区与/dev/sda2的结束扇区能对接上）

    创建逻辑分区

Command (m for help): n

Partition type:

   p   primary (3 primary, 0 extended, 1 free)

   e   extended

Select (default e): e   \\指定新建扩展分区

Selected partition 4

First sector (23068672-31457279, default 23068672): 

Using default value 23068672

Last sector, +sectors or +size{K,M,G} (23068672-31457279, default 31457279): +1G  \\指定扩展分区的大小

Partition 4 of type Extended and of size 1 GiB is set

Command (m for help): n 

All primary partitions are in use

Adding logical partition 5  \\ ID号1-4已经用完，系统直接使用逻辑分区ID的范围5-15

First sector (23070720-25165823, default 23070720): 

Using default value 23070720

Last sector, +sectors or +size{K,M,G} (23070720-25165823, default 25165823): 24000000  \\这里的结束扇区25165823-23070720=2095103*512/1024/1024=1022.99MB，即1GB，与指定的扩展分区大小相同

Partition 5 of type Linux and of size 453.8 MiB is set \\新建逻辑分区的大小是453.8MB

Command (m for help): n

All primary partitions are in use

Adding logical partition 6

First sector (24002049-25165823, default 24002560): 

Using default value 24002560

Last sector, +sectors or +size{K,M,G} (24002560-25165823, default 25165823):  \\这里的结束扇区ID与上述的相同

Using default value 25165823

Partition 6 of type Linux and of size 568 MiB is set

Command (m for help): p

Disk /dev/sda: 16.1 GB, 16106127360 bytes, 31457280 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 label type: dos

Disk identifier: 0x000a72d4

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048    20971519     9972736   8e  Linux LVM

/dev/sda3        20971520    23068671     1048576   83  Linux

/dev/sda4        23068672    25165823     1048576    5  Extended

/dev/sda5        23070720    24000000      464640+  83  Linux

/dev/sda6        24002560    25165823      581632   83  Linux  \\新建的逻辑分区

Command (m for help): w \\保存退出

 检查linux是否已经识别出新的分区查看/rroc/paritions文件

[root@localhost ~]# cat /proc/partitions 

major minor  #blocks  name

   8        0   15728640 sda

   8        1     512000 sda1

   8        2    9972736 sda2  \\新创建的/dev/sda3-6没有还没有识别出来

  11        0    4228096 sr0

 253        0    8880128 dm-0

 253        1    1048576 dm-1

强制让内核更新分区

[root@localhost ~]# partx -u /dev/sda 

[root@localhost ~]# cat /proc/partitions 

major minor  #blocks  name

   8        0   15728640 sda

   8        1     512000 sda1

   8        2    9972736 sda2

   8        3    1048576 sda3

   8        4          1 sda4

   8        5     464640 sda5

   8        6     581632 sda6 \\已识别出新分区

  11        0    4228096 sr0

 253        0    8880128 dm-0

 253        1    1048576 dm-1

[root@localhost ~]# 

格式化新建的分区mkfs命令

    把sda6、sda5格式为ext4

[root@localhost ~]# mkfs.ext4 -L test /dev/sda6

mke2fs 1.42.9 (28-Dec-2013)

Filesystem label=test

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

36400 inodes, 145408 blocks

7270 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=148897792

5 block groups

32768 blocks per group, 32768 fragments per group

7280 inodes per group

Superblock backups stored on blocks: 

32768, 98304

Allocating group tables: done                            

Writing inode tables: done                            

Creating journal (4096 blocks): done

Writing superblocks and filesystem accounting information: done

也可用 ext系列专用的格式化工具mke2fs

[root@localhost ~]# mke2fs -t ext3 -m 5 -L TEST_sda5 -b 4096 /dev/sda5 

mke2fs 1.42.9 (28-Dec-2013)

Filesystem label=TEST_sda5 \\标识符为TEST_sda5

OS type: Linux

Block size=4096 (log=2) \\block为4096

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

116224 inodes, 116160 blocks

5808 blocks (5.00%) reserved for the super user \\为管理员预留5%的空间

First data block=0

Maximum filesystem blocks=121634816

4 block groups

32768 blocks per group, 32768 fragments per group

29056 inodes per group

Superblock backups stored on blocks: 

32768, 98304

Allocating group tables: done                            

Writing inode tables: done                            

Creating journal (4096 blocks): done

Writing superblocks and filesystem accounting information: done

查看所有分区的属性使用blkid

[root@localhost ~]# blkid 

/dev/sda1: UUID="050a347a-4a99-4e80-a6b4-a4ed0a47eaa1" TYPE="xfs" 

/dev/sda2: UUID="dv2Krn-BlSL-4NBt-yduR-BXax-tChJ-V2YpbM" TYPE="LVM2_member" 

/dev/sda5: LABEL="TEST_sda5" UUID="b5b2b12b-236d-4578-845b-a5632ca5eafa" SEC_TYPE="ext2" TYPE="ext3"  

/dev/sda6: LABEL="test" UUID="a0a549a2-0aec-4ff6-bce8-f2dfdfa1539e" TYPE="ext4"  

/dev/sr0: UUID="2015-12-09-23-14-10-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos" 

/dev/mapper/centos-root: UUID="0adba78a-e1e3-4900-87c2-069105c6a1fc" TYPE="xfs" 

/dev/mapper/centos-swap: UUID="2228d7dd-b7ed-44fb-9f68-668fc942a542" TYPE="swap" 

使用fsck命令检测分区

[root@localhost ~]# fsck.ext3 -frc /dev/sda5   \\ f是强制检测  c是提示测试进度 r进行交互式检测

e2fsck 1.42.9 (28-Dec-2013)

Checking for bad blocks (read-only test): done                                                 

TEST_sda5: Updating bad block inode.

Pass 1: Checking inodes, blocks, and sizes

Pass 2: Checking directory structure

Pass 3: Checking directory connectivity

Pass 4: Checking reference counts

Pass 5: Checking group summary information

TEST_sda5: ***** FILE SYSTEM WAS MODIFIED *****

TEST_sda5: 11/116224 files (0.0% non-contiguous), 7837/116160 blocks

[root@localhost ~]#