本人对Linux本来就不是很熟,但是由于各种原因开始捣鼓CentOS(大家都说是这个系统比较好学),开始预计20G的磁盘就足够了,没想到装Oracle就直接报磁盘空间不足,更别提在Tomcat下部署近500M的网站系统。

       网上度娘了很多版本,试了三天也试出来,各种异常各种痛苦,几度都有放弃的想法,想的还不如直接重新装一个都比折腾这东西快,也省时间精力。

       纷纷扰扰的各种贴,感觉说的内容都差不多,但是晚上突然搜索到了这篇贴,值的赞一个,起码说明了原理

      ,楼主说明其中原理,尝试从中慢慢的理解。

 

[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               cl
  PV Size               19.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              4863
  Free PE               0
  Allocated PE          4863
  PV UUID               rZ3sjT-Lwle-A5z2-3pvl-3NQp-7M4W-walDyl

[root@localhost ~]# df -h


文件系统 容量 已用 可用 已用% 挂载点

/dev/mapper/cl-root   17G  5.1G   12G   30% /
devtmpfs             478M     0  478M    0% /dev
tmpfs                489M   88K  489M    1% /dev/shm
tmpfs                489M  7.1M  482M    2% /run
tmpfs                489M     0  489M    0% /sys/fs/cgroup
/dev/sda1           1014M  139M  876M   14% /boot
tmpfs                 98M  8.0K   98M    1% /run/user/0
/dev/sr0             4.1G  4.1G     0  100% /run/media/root/CentOS 7 x86_64
[root@localhost ~]# df -TH


文件系统 类型 容量 已用 可用 已用% 挂载点

/dev/mapper/cl-root xfs        19G  5.4G   13G   30% /
devtmpfs            devtmpfs  501M     0  501M    0% /dev
tmpfs               tmpfs     512M   91k  512M    1% /dev/shm
tmpfs               tmpfs     512M  7.4M  505M    2% /run
tmpfs               tmpfs     512M     0  512M    0% /sys/fs/cgroup
/dev/sda1           xfs       1.1G  146M  919M   14% /boot
tmpfs               tmpfs     103M  8.2k  103M    1% /run/user/0
/dev/sr0            iso9660   4.4G  4.4G     0  100% /run/media/root/CentOS 7 x86_64
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/cl/swap
  LV Name                swap
  VG Name                cl
  LV UUID                NeSZ9n-Ic3d-Jotd-1QSq-Q2Y4-uimw-FW0awj
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-07-14 06:08:39 +0800
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                mqTC5Z-X6hL-byB7-ruSX-bwpn-ApvY-IKU01b
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-07-14 06:08:39 +0800
  LV Status              available
  # open                 1
  LV Size                17.00 GiB
  Current LE             4351
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

[root@localhost ~]# pvcreate /dev/sda4
  Device /dev/sda4 not found (or ignored by filtering).
[root@localhost ~]# pvcreate /dev/pv1
  Device /dev/pv1 not found (or ignored by filtering).
[root@localhost ~]# pvcreate /dev/sda/pv1
  Device /dev/sda/pv1 not found (or ignored by filtering).
[root@localhost ~]# pvcreate pv1 /dev/sda
  Device pv1 not found (or ignored by filtering).
  Device /dev/sda not found (or ignored by filtering).
[root@localhost ~]# lvm
lvm> p
  No such command 'p'.  Try 'help'.
lvm> pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               cl
  PV Size               19.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              4863
  Free PE               0
  Allocated PE          4863
  PV UUID               rZ3sjT-Lwle-A5z2-3pvl-3NQp-7M4W-walDyl

lvm> pvs
  PV         VG Fmt  Attr PSize  PFree
  /dev/sda2  cl lvm2 a--  19.00g    0 
lvm> pvcreate /dev/pv1
  Device /dev/pv1 not found (or ignored by filtering).
lvm> q
  No such command 'q'.  Try 'help'.
lvm> ^C
[root@localhost ~]# fdisk /dev/sda


欢迎使用 fdisk (util-linux 2.23.2)。

更改将停留在内存中,直到您决定将更改写入磁盘。
使用写入命令前请三思。

命令(输入 m 获取帮助):p

磁盘 /dev/sda:42.9 GB, 42949672960 字节,83886080 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d7fd8

设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM

命令(输入 m 获取帮助):

q
[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               cl
  PV Size               19.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              4863
  Free PE               0
  Allocated PE          4863
  PV UUID               rZ3sjT-Lwle-A5z2-3pvl-3NQp-7M4W-walDyl

[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/cl/swap
  LV Name                swap
  VG Name                cl
  LV UUID                NeSZ9n-Ic3d-Jotd-1QSq-Q2Y4-uimw-FW0awj
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-07-14 06:08:39 +0800
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                mqTC5Z-X6hL-byB7-ruSX-bwpn-ApvY-IKU01b
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-07-14 06:08:39 +0800
  LV Status              available
  # open                 1
  LV Size                17.00 GiB
  Current LE             4351
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

[root@localhost ~]# lvextend -L +10G /dev/cl/root
  Insufficient free space: 2560 extents needed, but only 0 available
[root@localhost ~]# fdisk -l

磁盘 /dev/sda:42.9 GB, 42949672960 字节,83886080 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d7fd8

设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM

磁盘 /dev/mapper/cl-root:18.2 GB, 18249416704 字节,35643392 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节

磁盘 /dev/mapper/cl-swap:2147 MB, 2147483648 字节,4194304 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节

[root@localhost ~]# pvcreate /dev/sda3
Device /dev/sda3 not found (or ignored by filtering).
[root@localhost ~]# fdisk /dev/sda
欢迎使用 fdisk (util-linux 2.23.2)。

更改将停留在内存中,直到您决定将更改写入磁盘。
使用写入命令前请三思。

命令(输入 m 获取帮助):n

Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): 3


无效的分区类型“3”

命令(输入 m 获取帮助):n

Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): 
Using default response p


分区号 (3,4,默认 3):
起始 扇区 (41943040-83886079,默认为 41943040):
将使用默认值 41943040
Last 扇区, +扇区 or +size{K,M,G} (41943040-83886079,默认为 83886079):
将使用默认值 83886079
分区 3 已设置为 Linux 类型,大小设为 20 GiB

命令(输入 m 获取帮助):p

磁盘 /dev/sda:42.9 GB, 42949672960 字节,83886080 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d7fd8

设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
/dev/sda3 41943040 83886079 20971520 83 Linux

命令(输入 m 获取帮助):pvcreate /dev/sda3

磁盘 /dev/sda:42.9 GB, 42949672960 字节,83886080 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理):512 字节 / 512 字节
I/O 大小(最小/最佳):512 字节 / 512 字节
磁盘标签类型:dos
磁盘标识符:0x000d7fd8

设备 Boot Start End Blocks Id System

/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    41943039    19921920   8e  Linux LVM
/dev/sda3        41943040    83886079    20971520   83  Linux

命令(输入 m 获取帮助):

q
[root@localhost ~]# pvcreate /dev/sda3
  Device /dev/sda3 not found (or ignored by filtering).
[root@localhost ~]#