逻辑卷管理实验---缩减/home目录使用空间并创建新的LVM

参考：http://blog.51cto.com/dreamfire/1084729
实验环境:redhat6.5

实验过程
显示物理卷：
[root@jing1 ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               vg_jing1
  PV Size               299.51 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              76674
  Free PE               142
  Allocated PE          76532
  PV UUID               fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p
   
查看磁盘挂载：
[root@jing1 ~]# df -h 
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_jing1-lv_root  231G   27G  193G  13% /
tmpfs                          16G  228K   16G   1% /dev/shm
/dev/sda1                     485M   39M  421M   9% /boot
/dev/mapper/vg_jing1-lv_home   49G  226M   46G   1% /home
/dev/sr0                      3.6G  3.6G     0 100% /media/RHEL_6.5 x86_64 Disc 1
umount home目录：
[root@jing1 /]# umount /home
检查lvm：
[root@jing1 /]# e2fsck -f /dev/vg_jing1/lv_home
e2fsck 1.41.12 (17-May-2010)
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
/dev/vg_jing1/lv_home: 504/3203072 files (0.0% non-contiguous), 258764/12800000 blocks
resize lvm（注意不要在生产环境使用）：
[root@jing1 /]# resize2fs  /dev/vg_jing1/lv_home 2G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/vg_jing1/lv_home to 524288 (4k) blocks.
The filesystem on /dev/vg_jing1/lv_home is now 524288 blocks long.
减少lvm空间：
[root@jing1 /]# lvreduce -L 2G /dev/vg_jing1/lv_home 
  WARNING: Reducing active logical volume to 2.00 GiB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv_home? [y/n]: y
  Reducing logical volume lv_home to 2.00 GiB
  Logical volume lv_home successfully resized
重新挂载/home目录
[root@jing1 /]# mount /dev/vg_jing1/lv_home /home
[root@jing1 /]# df -h 
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_jing1-lv_root  231G   27G  193G  13% /
tmpfs                          16G  228K   16G   1% /dev/shm
/dev/sda1                     485M   39M  421M   9% /boot
/dev/sr0                      3.6G  3.6G     0 100% /media/RHEL_6.5 x86_64 Disc 1
/dev/mapper/vg_jing1-lv_home  2.0G  198M  1.7G  11% /home
[root@jing1 /]# fdisk -l


Disk /dev/sda: 322.1 GB, 322122547200 bytes
255 heads, 63 sectors/track, 39162 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: 0x000ba939


   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64       39163   314059776   8e  Linux LVM


Disk /dev/mapper/vg_jing1-lv_root: 251.7 GB, 251658240000 bytes
255 heads, 63 sectors/track, 30595 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




Disk /dev/mapper/vg_jing1-lv_swap: 16.9 GB, 16911433728 bytes
255 heads, 63 sectors/track, 2056 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




Disk /dev/mapper/vg_jing1-lv_home: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 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
空间释放到物理卷中：
[root@jing1 /]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               vg_jing1
  PV Size               299.51 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              76674
  Free PE               12130
  Allocated PE          64544
  PV UUID               fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p
查看卷组发现减少的空间已经自动释放到卷组中：
[root@jing1 /]# vgdisplay
  --- Volume group ---
  VG Name               vg_jing1
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               299.51 GiB
  PE Size               4.00 MiB
  Total PE              76674
  Alloc PE / Size       64544 / 252.12 GiB
  Free  PE / Size       12130 / 47.38 GiB
  VG UUID               1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe
创建名为lv_test的lvm：
[root@jing1 /]# lvcreate -L 15G -n lv_test vg_jing1
  Logical volume "lv_test" created
[root@jing1 /]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_root
  LV Name                lv_root
  VG Name                vg_jing1
  LV UUID                shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:09 +0800
  LV Status              available
  # open                 1
  LV Size                234.38 GiB
  Current LE             60000
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_swap
  LV Name                lv_swap
  VG Name                vg_jing1
  LV UUID                FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:50 +0800
  LV Status              available
  # open                 1
  LV Size                15.75 GiB
  Current LE             4032
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_home
  LV Name                lv_home
  VG Name                vg_jing1
  LV UUID                FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:51 +0800
  LV Status              available
  # open                 1
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_test
  LV Name                lv_test
  VG Name                vg_jing1
  LV UUID                l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-11-28 13:19:39 +0800
  LV Status              available
  # open                 0
  LV Size                15.00 GiB
  Current LE             3840
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3
  
  
[root@jing1 /]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_root
  LV Name                lv_root
  VG Name                vg_jing1
  LV UUID                shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:09 +0800
  LV Status              available
  # open                 1
  LV Size                234.38 GiB
  Current LE             60000
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_swap
  LV Name                lv_swap
  VG Name                vg_jing1
  LV UUID                FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:50 +0800
  LV Status              available
  # open                 1
  LV Size                15.75 GiB
  Current LE             4032
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_home
  LV Name                lv_home
  VG Name                vg_jing1
  LV UUID                FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:51 +0800
  LV Status              available
  # open                 1
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_test
  LV Name                lv_test
  VG Name                vg_jing1
  LV UUID                l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-11-28 13:19:39 +0800
  LV Status              available
  # open                 0
  LV Size                15.00 GiB
  Current LE             3840
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3
   
[root@jing1 /]# cat /etc/fstab 


#
# /etc/fstab
# Created by anaconda on Fri Feb 10 10:35:59 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/vg_jing1-lv_root /                       ext4    defaults        1 1
UUID=3b96274e-550d-43fa-96c3-2a4b0b6684dc /boot                   ext4    defaults        1 2
/dev/mapper/vg_jing1-lv_home /home                   ext4    defaults        1 2
/dev/mapper/vg_jing1-lv_swap swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
格式化lvm：
[root@jing1 /]# mkfs.ext4 /dev/vg_jing1/lv_test 
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
983040 inodes, 3932160 blocks
196608 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4026531840
120 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208


Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done


This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
挂载lv_test到/test目录
[root@jing1 /]# mkdir /test
[root@jing1 /]# mount /dev/vg_jing1/lv_test /test
[root@jing1 /]# df -h 
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_jing1-lv_root  231G   27G  193G  13% /
tmpfs                          16G  228K   16G   1% /dev/shm
/dev/sda1                     485M   39M  421M   9% /boot
/dev/sr0                      3.6G  3.6G     0 100% /media/RHEL_6.5 x86_64 Disc 1
/dev/mapper/vg_jing1-lv_home  2.0G  198M  1.7G  11% /home
/dev/mapper/vg_jing1-lv_test   15G  166M   14G   2% /test


接下删除lv_test逻辑卷，并创建名为lv_asm的逻辑卷用作数据库使用：
[root@jing1 /]# umount /test
[root@jing1 /]# 
[root@jing1 /]# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_jing1-lv_root  231G   27G  193G  13% /
tmpfs                          16G  228K   16G   1% /dev/shm
/dev/sda1                     485M   39M  421M   9% /boot
/dev/sr0                      3.6G  3.6G     0 100% /media/RHEL_6.5 x86_64 Disc 1
/dev/mapper/vg_jing1-lv_home  2.0G  198M  1.7G  11% /home
[root@jing1 /]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_root
  LV Name                lv_root
  VG Name                vg_jing1
  LV UUID                shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:09 +0800
  LV Status              available
  # open                 1
  LV Size                234.38 GiB
  Current LE             60000
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_swap
  LV Name                lv_swap
  VG Name                vg_jing1
  LV UUID                FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:50 +0800
  LV Status              available
  # open                 1
  LV Size                15.75 GiB
  Current LE             4032
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_home
  LV Name                lv_home
  VG Name                vg_jing1
  LV UUID                FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:51 +0800
  LV Status              available
  # open                 1
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_test
  LV Name                lv_test
  VG Name                vg_jing1
  LV UUID                l1IhX5-LOKf-lOaH-K5nZ-3wod-2X7m-07cogG
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-11-28 13:19:39 +0800
  LV Status              available
  # open                 0
  LV Size                15.00 GiB
  Current LE             3840
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3


[root@jing1 /]# vgdisplay
  --- Volume group ---
  VG Name               vg_jing1
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                4
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               299.51 GiB
  PE Size               4.00 MiB
  Total PE              76674
  Alloc PE / Size       68384 / 267.12 GiB
  Free  PE / Size       8290 / 32.38 GiB
  VG UUID               1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe
   
[root@jing1 /]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               vg_jing1
  PV Size               299.51 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              76674
  Free PE               8290
  Allocated PE          68384
  PV UUID               fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p
   
 
[root@jing1 /]# lvremove /dev/vg_jing1/lv_test 
Do you really want to remove active logical volume lv_test? [y/n]: y
  Logical volume "lv_test" successfully removed
[root@jing1 /]# 
[root@jing1 /]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               vg_jing1
  PV Size               299.51 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              76674
  Free PE               12130
  Allocated PE          64544
  PV UUID               fusHvY-5mpq-X2bO-pbdC-2AWl-m4wO-cUf07p
   
[root@jing1 /]# vgdisplay
  --- Volume group ---
  VG Name               vg_jing1
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  7
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               299.51 GiB
  PE Size               4.00 MiB
  Total PE              76674
  Alloc PE / Size       64544 / 252.12 GiB
  Free  PE / Size       12130 / 47.38 GiB
  VG UUID               1IW8eG-arlp-kvje-wFLT-pC5d-AcY0-RulpNe
   
[root@jing1 /]# 
[root@jing1 /]# lvcreate -L 45G -n lv_asm vg_jing1
  Logical volume "lv_asm" created
[root@jing1 /]# mkfs.ext4 /dev/vg_jing1/lv_asm
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
2949120 inodes, 11796480 blocks
589824 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
360 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424


Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done


This filesystem will be automatically checked every 30 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
[root@jing1 /]# 
[root@jing1 /]# 
[root@jing1 /]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_root
  LV Name                lv_root
  VG Name                vg_jing1
  LV UUID                shkBg6-9RqZ-AhDG-qfVf-d51Z-nsoS-qvF7Da
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:09 +0800
  LV Status              available
  # open                 1
  LV Size                234.38 GiB
  Current LE             60000
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_swap
  LV Name                lv_swap
  VG Name                vg_jing1
  LV UUID                FQE8o0-yOKG-S4ip-Cvry-qSdk-v3f9-uPSa1e
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:50 +0800
  LV Status              available
  # open                 1
  LV Size                15.75 GiB
  Current LE             4032
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_home
  LV Name                lv_home
  VG Name                vg_jing1
  LV UUID                FTLjIk-zr5B-M5ak-WdXB-c2Zs-c0eC-xZ6YBp
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-02-10 10:33:51 +0800
  LV Status              available
  # open                 1
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/vg_jing1/lv_asm
  LV Name                lv_asm
  VG Name                vg_jing1
  LV UUID                Fa3ufV-6Pjn-Sncv-KyKd-x6BD-GWoi-yFXjMv
  LV Write Access        read/write
  LV Creation host, time jing1, 2017-11-28 14:00:39 +0800
  LV Status              available
  # open                 0
  LV Size                45.00 GiB
  Current LE             11520
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:3