Linux文件系统LVM建立

通过fdisk分区：

[root@dream /]# fdisk -l
Device Boot      Start         End      Blocks   Id   System
/dev/vdb1            2048     2099199     1048576   8e   Linux LVM
/dev/vdb2         2099200     4196351     1048576   8e   Linux LVM

pvs|pvdisplay                                                         ###查看pv
vgs|vgdisplay                                                         ###查看vg
lvs|lvdisplay                                                         ###查看lvm

watch -n 1 \
'echo "=== pvinfo ==="\
;pvs\
;echo "=== vginfo ==="\
;vgs\
;echo === lvinfo ===\
;lvs'

[root@dream /]# pvcreate /dev/vdb1                                  ###把/dev/vdb1建立成pv
WARNING: xfs signature detected on /dev/vdb1 at offset 0. Wipe it? [y/n] y
Wiping xfs signature on /dev/vdb1.
Physical volume "/dev/vdb1" successfully created

[root@dream /]# vgcreate -s 2M vg0 /dev/vdb1                       ###-s:vg中pe（最小单位）的大小，名字取为vg0
Volume group "vg0" successfully created

[root@dream /]# lvcreate -L 100M -n lv0 vg0                         ###从vg中取出100M建立lvm
Logical volume "lv0" created

[root@dream /]# mkfs.xfs /dev/vg0/lv0
meta-data=/dev/vg0/lv0           isize=256    agcount=4,  agsize=6400 blks
=                       sectsz=512   attr=2,  projid32bit=1
=                       crc=0
data     =                       bsize=4096    blocks=25600, imaxpct=25
=                       sunit=0      swidth=0  blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal log           bsize=4096   blocks=853, version=2
=                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@dream /]# mount /dev/vg0/lv0 /mnt
[root@dream /]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/vda1             10G  3.0G  7.1G  30% /
devtmpfs             459M     0  459M   0% /dev
tmpfs                474M   80K  474M   1% /dev/shm
tmpfs                474M   13M  462M   3% /run
tmpfs                474M     0  474M   0% /sys/fs/cgroup
/dev/mapper/vg0-lv0   97M  5.2M   92M   6% /mnt

LVM在线拉伸

[root@dream /]# lvextend -L 500M /dev/vg0/lv0                             ###扩展lvm的容量(直接从vg中取)拉伸到50M
Extending logical volume lv0 to 500.00 MiB
Logical volume lv0 successfully resized
[root@dream /]# xfs_growfs /dev/vg0/lv0                                   ###扩大文件系统xfs
meta-data=/dev/mapper/vg0-lv0    isize=256    agcount=4, agsize=6400 blks
=                       sectsz=512   attr=2, projid32bit=1
=                       crc=0
data     =                       bsize=4096   blocks=25600, imaxpct=25
=                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal               bsize=4096   blocks=853, version=2
=                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 25600 to 128000

[root@dream /]# pvcreate /dev/vdb2
WARNING: xfs signature detected on /dev/vdb2 at offset 0. Wipe it? [y/n] y
Wiping xfs signature on /dev/vdb2.
Physical volume "/dev/vdb2" successfully created

[root@dream /]# vgextend vg0 /dev/vdb2
Volume group "vg0" successfully extended

[root@dream /]# lvextend -L 1.5G /dev/vg0/lv0
Extending logical volume lv0 to 1.50 GiB
Logical volume lv0 successfully resized
[root@dream /]# xfs_growfs /dev/vg0/lv0
meta-data=/dev/mapper/vg0-lv0    isize=256    agcount=20, agsize=6400 blks
=                       sectsz=512   attr=2, projid32bit=1
=                       crc=0
data     =                       bsize=4096   blocks=128000, imaxpct=25
=                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal               bsize=4096   blocks=853, version=2
=                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 128000 to 393216

ext4文件系统中拉伸

[root@dream /]# umount /mnt/
[root@dream /]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        10G  3.0G  7.1G  30% /
devtmpfs        459M     0  459M   0% /dev
tmpfs           474M   80K  474M   1% /dev/shm
tmpfs           474M   13M  462M   3% /run
tmpfs           474M     0  474M   0% /sys/fs/cgroup
[root@dream /]# mkfs.ext4 /dev/vg0/lv0                                         ###格式化为ext4格式

root@dream /]# lvextend -L 1.8G /dev/vg0/lv0
Rounding size to boundary between physical extents: 1.80 GiB
Extending logical volume lv0 to 1.80 GiB
Logical volume lv0 successfully resized
[root@dream /]# resize2fs /dev/vg0/lv0 1.8G
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Invalid new size: 1.8G

[root@dream /]# e2fsck -f /dev/vg0/lv0                                        ###扫描数据大小，预防造成数据损失
e2fsck 1.42.9 (28-Dec-2013)
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/vg0/lv0: 11/98304 files (9.1% non-contiguous), 15524/393216 blocks
[root@dream /]# resize2fs /dev/vg0/lv0 1G                                    ###减小文件系统
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/vg0/lv0 to 262144 (4k) blocks.
The filesystem on /dev/vg0/lv0 is now 262144 blocks long.
[root@dream /]# lvreduce -L 1G /dev/vg0/lv0                                  ###减小设备大小
WARNING: Reducing active logical volume to 1.00 GiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv0? [y/n]: y
Reducing logical volume lv0 to 1.00 GiB
Logical volume lv0 successfully resized

pvmove  /dev/vdb1 /dev/vdb2                                             ###把/dev/vdb1数据拷贝到vdb2
vgreduce westos  /dev/vdb1                                              ###把/dev/vdb1从westos中移出来
pvremove  /dev/vdb1                                                     ###移出设备（未使用的直接这一步就好）

LVM快照

[root@dream /]# mount /dev/vg0/lv0 /mnt
[root@dream /]# cd /mnt
[root@dream mnt]# ls
lost+found
[root@dream mnt]# touch file{1..10}
[root@dream mnt]# ls
file1   file2  file4  file6  file8  lost+found
file10  file3  file5  file7  file9
[root@dream /]# lvcreate  -L 10M -n lv0-backup -s /dev/vg0/lv0         ###创建快照
Logical volume "lv0-backup" created
[root@dream /]# mount /dev/vg0/lv0-backup /mnt
[root@dream /]# ls /mnt
file1   file2  file4  file6  file8  lost+found
file10  file3  file5  file7  file9
[root@dream /]# rm -rf /mnt/*
[root@dream /]# umount /dev/vg0/lv0-backup
[root@dream /]# lvcreate  -L 10M -n lv0-backup -s /dev/vg0/lv0
mount /dev/vg0/lv0-backup /mnt/
ls /mnt

lvm的删除

lvremove /dev/vg0/lv0
vgremove vg0
pvremove /dev/vdb1
fdisk /dev/vdb

vgreduce --removemissing vg0