磁盘分区与逻辑卷管理

磁盘命名

IDE驱动器

/dev/hda、/dev/hdb、/dev/hdc...

/dev/hda1、/dev/hda2、/dev/hda3...

SATA驱动器

/dev/sda、/dev/sdb、/dev/sdc...

/dev/sda1、/dev/sda2、/dev/sda3...

 

创建分区

fdisk

注意：需要超级用户权限

所有操作都在内存中进行，只要不w就不会保存到磁盘

常用参数	描述
d	删除分区
l	显示可用分区类型
m	帮助
n	添加一个新分区
p	显示当前分区表
q	退出
t	修改分区的系统ID
w	将分区表写入磁盘

 

分区可按主分区或扩展分区创建，主分区文件系统可直接格式化，扩展分区只能容纳其他逻辑分区。

扩展分区出现的原因是每个存储设备上只能有4个主分区，可以通过在扩展分区上创建多个逻辑分区进行扩展。

[root@tzPC ~]# fdisk /dev/sdb
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/sdb: 21.5 GB, 21474836480 bytes, 41943040 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: 0x892ef256

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 
First sector (2048-41943039, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +2G
Partition 1 of type Linux and of size 2 GiB is set

Command (m for help): p

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 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: 0x892ef256

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   83  Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

 

Id列定义了Linux怎样对待该分区，默认是83，可使用l参数查看，对应的是Linux文件系统

某些发行版生成新分区后并不会更新分区，需要使用partprob或hdparm命令，或者重启系统才会更新分区表

创建文件系统

查看本机文件系统几个命令

df -T 
parted -l
blkid
lsblk -f 

 

创建ext4文件系统类型，相当于格式化分区

[root@tzPC ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131072 inodes, 524288 blocks
26214 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=536870912
16 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
    32768, 98304, 163840, 229376, 294912

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done 

 

挂载

[root@tzPC ~]# mkdir /mnt/sdb1
[root@tzPC ~]# mount -t ext4 /dev/sdb1 /mnt/sdb1/
[root@tzPC ~]# df -Th /mnt/sdb1
Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/sdb1      ext4  2.0G  6.0M  1.8G   1% /mnt/sdb1

文件系统的检查与修复

每个文件系统都有各自恢复命令，为了简便，有一个通用命令检查和修复大部分类型的Linux文件系统。

fsck

使用/etc/fstab文件来自动决定正常挂载到系统上的存储设备的文件系统，如果未挂载，需要使用-t指定文件系统类型。

使用前必须先卸载文件系统，检查完成后重新挂载。

 

逻辑卷管理

物理卷（PV）

硬盘

 

卷组（VG）

多个物理卷可以形成一个卷组，逻辑卷管理系统将卷组视为一个物理盘，而卷组可以是由分布在多个物理硬盘上的多个物理分区组成。

 

逻辑卷（LV）

可格式化挂载

 

定义物理卷

修改分区系统ID使其转换成Linux LVM格式

[root@tzPC ~]# fdisk /dev/sdb
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): t
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux LVM' to 'Linux LVM'

Command (m for help): p

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 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: 0x892ef256

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   8e  Linux LVM

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

 在创建一个Linux LVM的分区

Command (m for help): p

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 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: 0x892ef256

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     4196351     2097152   8e  Linux LVM
/dev/sdb2         4196352     8390655     2097152   8e  Linux LVM

 更新一下分区表

[root@tzPC ~]# partprobe
Warning: Unable to open /dev/sr0 read-write (Read-only file system).  /dev/sr0 has been opened read-only.

 没有此命令则使用yum安装

[root@tzPC ~]# yum install -y parted

 将硬盘转换成物理卷

如果挂载了 分区请先卸载

[root@tzPC ~]# pvcreate /dev/sdb1 /dev/sdb2
  Physical volume "/dev/sdb1" successfully created.
  Physical volume "/dev/sdb2" successfully created.

 显示已创建的物理卷列表

[root@tzPC ~]# pvdisplay /dev/sdb1 /dev/sdb2
  "/dev/sdb2" is a new physical volume of "2.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb2
  VG Name               
  PV Size               2.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               q4rZeD-Bjun-XjyZ-IgnH-Tj96-4rad-WRE33J
   
  "/dev/sdb1" is a new physical volume of "2.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb1
  VG Name               
  PV Size               2.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               8VjENe-yEZp-i0FI-4X8r-0yr2-n8G1-C7Pvza

 创建卷组

[root@tzPC ~]# vgcreate vol_sdb /dev/sdb1 /dev/sdb2
  Volume group "vol_sdb" successfully created

查看

[root@tzPC ~]# pvdisplay /dev/sdb1 /dev/sdb2
  "/dev/sdb2" is a new physical volume of "2.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb2
  VG Name               
  PV Size               2.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               q4rZeD-Bjun-XjyZ-IgnH-Tj96-4rad-WRE33J
   
  "/dev/sdb1" is a new physical volume of "2.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb1
  VG Name               
  PV Size               2.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               8VjENe-yEZp-i0FI-4X8r-0yr2-n8G1-C7Pvza
   
[root@tzPC ~]# vgcreate vol_sdb /dev/sdb1 /dev/sdb2
  Volume group "vol_sdb" successfully created
[root@tzPC ~]# vgdisplay vol_sdb
  --- Volume group ---
  VG Name               vol_sdb
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               3.99 GiB
  PE Size               4.00 MiB
  Total PE              1022
  Alloc PE / Size       0 / 0   
  Free  PE / Size       1022 / 3.99 GiB
  VG UUID               Tpydaw-urdy-8Ac7-84uf-D9kL-smb2-zT7jgD

创建逻辑卷

-l选项定义了为逻辑卷指定多少可用的卷组空间，可按百分比指定

[root@tzPC ~]# lvcreate -l 100%FREE -n lv_sdb vol_sdb
  Logical volume "lv_sdb" created.

 查看

[root@tzPC ~]# lvdisplay vol_sdb
  --- Logical volume ---
  LV Path                /dev/vol_sdb/lv_sdb
  LV Name                lv_sdb
  VG Name                vol_sdb
  LV UUID                bbB64W-Z2kZ-Q7hn-b1jL-G7jF-mdU0-cqUCic
  LV Write Access        read/write
  LV Creation host, time tzPC, 2020-08-08 18:27:56 +0800
  LV Status              available
  # open                 0
  LV Size                3.99 GiB
  Current LE             1022
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

 格式化

[root@tzPC ~]# mkfs.ext4 /dev/vol_sdb/lv_sdb 

 

挂载

[root@tzPC ~]# mkdir /mnt/vol_sdb
[root@tzPC ~]# mount /dev/vol_sdb/lv_sdb /mnt/vol_sdb/
[root@tzPC ~]# df -hT /mnt/vol_sdb/
Filesystem                 Type  Size  Used Avail Use% Mounted on
/dev/mapper/vol_sdb-lv_sdb ext4  3.9G   16M  3.7G   1% /mnt/vol_sdb

修改LVM大小

#待补充