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lvm拉伸与快照
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一.拉伸
*用fdisk分区
*构建pv
*将pv加入vg
*将pv内的pe加入lv
*通过resize将文件系统的容量增加
1.分区
[root@server3 ~]# fdisk /dev/vdb
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): n
All primary partitions are in use
Adding logical partition 6
First sector (8394752-20971519, default 8394752):
Using default value 8394752
Last sector, +sectors or +size{K,M,G} (8394752-20971519, default 20971519): +1G
Partition 6 of type Linux and of size 1 GiB is set
Command (m for help): p
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0xa859763d
Device Boot Start End Blocks Id System
/dev/vdb1 2048 2099199 1048576 8e Linux LVM
/dev/vdb2 2099200 4196351 1048576 8e Linux LVM
/dev/vdb3 4196352 6293503 1048576 8e Linux LVM
/dev/vdb4 6293504 20971519 7339008 5 Extended
/dev/vdb5 6295552 8392703 1048576 8e Linux LVM
/dev/vdb6 8394752 10491903 1048576 83 Linux
Command (m for help): t
Partition number (1-6, default 6): 6
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0xa859763d
Device Boot Start End Blocks Id System
/dev/vdb1 2048 2099199 1048576 8e Linux LVM
/dev/vdb2 2099200 4196351 1048576 8e Linux LVM
/dev/vdb3 4196352 6293503 1048576 8e Linux LVM
/dev/vdb4 6293504 20971519 7339008 5 Extended
/dev/vdb5 6295552 8392703 1048576 8e Linux LVM
/dev/vdb6 8394752 10491903 1048576 8e Linux LVM
2.构建pv
[root@server3 ~]# pvcreate /dev/vdb6
Physical volume "/dev/vdb6" successfully created.
[root@server3 ~]# pvscan
PV /dev/vdb1 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb2 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb3 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb5 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb6 lvm2 [1.00 GiB]
Total: 5 [4.94 GiB] / in use: 4 [3.94 GiB] / in no VG: 1 [1.00 GiB]
3.将pv加入vg
[root@server3 ~]# vgextend vgn /dev/vdb6
Volume group "vgn" successfully extended
[root@server3 ~]# vgdisplay
--- Volume group ---
VG Name vgn
System ID
Format lvm2
Metadata Areas 5
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 5
Act PV 5
VG Size 4.92 GiB
PE Size 16.00 MiB
Total PE 315
Alloc PE / Size 252 / 3.94 GiB
Free PE / Size 63 / 1008.00 MiB **这里显示的时未使用的pe，-l参数可以看这里
VG UUID JjHOlH-RdcV-71dR-4wmK-NQ3N-pnRS-1y5dIV
4.将pv内的pe加入lv
[root@server3 ~]# lvresize -l +63 /dev/vdb
/dev/vdb1 /dev/vdb2 /dev/vdb3 /dev/vdb5 /dev/vdb6
[root@server3 ~]# lvresize -l +63 /dev/vgn/lvn
Size of logical volume vgn/lvn changed from 3.94 GiB (252 extents) to 4.92 GiB (315 extents).
Logical volume vgn/lvn successfully resized.
[root@server3 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vgn/lvn
LV Name lvn
VG Name vgn
LV UUID 3cZBXM-Ef2z-wDLR-Fyxx-TmzD-Payq-BJ6eTm
LV Write Access read/write
LV Creation host, time server3, 2019-01-21 20:32:58 +0800
LV Status available
# open 1
LV Size 4.92 GiB
Current LE 315
Segments 5
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 252:0
5.文件系统的扩展
[root@server3 ~]# df -h
/dev/mapper/vgn-lvn 3.9G 16M 3.6G 1% /mnt/lvm
[root@server3 ~]# resize2fs /dev/vgn/lvn
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/vgn/lvn is mounted on /mnt/lvm; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/vgn/lvn is now 1290240 blocks long.
[root@server3 ~]# df -h /dev/vgn/lvn
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vgn-lvn 4.8G 16M 4.6G 1% /mnt/lvm
二.缩小LV容量
[root@server3 ~]# pvscan
PV /dev/vdb1 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb2 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb3 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb5 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb6 VG vgn lvm2 [1008.00 MiB / 0 free]
Total: 5 [4.92 GiB] / in use: 5 [4.92 GiB] / in no VG: 0 [0 ]
[root@server3 ~]# umount /dev/vgn/lvn
[root@server3 ~]# resize2fs /dev/vgn/lvn 4032M
resize2fs 1.42.9 (28-Dec-2013)
Please run 'e2fsck -f /dev/vgn/lvn' first.
[root@server3 ~]# e2fsck -f /dev/vgn/lvn
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/vgn/lvn: 11/322560 files (0.0% non-contiguous), 40670/1290240 blocks
[root@server3 ~]# resize2fs /dev/vgn/lvn 4032M
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/vgn/lvn to 1032192 (4k) blocks.
The filesystem on /dev/vgn/lvn is now 1032192 blocks long.
[root@server3 ~]# mount /dev/vgn/lvn /mnt/lvm
[root@server3 ~]# df -h /mnt/lvm/
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vgn-lvn 3.9G 16M 3.6G 1% /mnt/lvm
可以通过pvdisplay查看pe个数
[root@server3 ~]# lvresize -l 63 /dev/vgn/lvn
WARNING: Reducing active and open logical volume to 1008.00 MiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce vgn/lvn? [y/n]: y
Size of logical volume vgn/lvn changed from 4.92 GiB (315 extents) to 1008.00 MiB (63 extents).
Logical volume vgn/lvn successfully resized.
[root@server3 ~]# pvscan
PV /dev/vdb1 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb2 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb3 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb5 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb6 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
Total: 5 [4.92 GiB] / in use: 5 [4.92 GiB] / in no VG: 0 [0 ]
[root@server3 ~]# pvmove /dev/vdb1 /dev/vdb6
/dev/vdb1: Moved: 7.94%
/dev/vdb1: Moved: 100.00%
[root@server3 ~]# vgreduce vgn /dev/vdb1
Removed "/dev/vdb1" from volume group "vgn"
[root@server3 ~]# pvscan
PV /dev/vdb2 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb3 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb5 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb6 VG vgn lvm2 [1008.00 MiB / 0 free]
PV /dev/vdb1 lvm2 [1.00 GiB]
Total: 5 [4.94 GiB] / in use: 4 [3.94 GiB] / in no VG: 1 [1.00 GiB]
[root@server3 ~]# pvremove /dev/vdb1
Labels on physical volume "/dev/vdb1" successfully wiped.
[root@server3 ~]# pvscan
PV /dev/vdb2 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb3 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb5 VG vgn lvm2 [1008.00 MiB / 1008.00 MiB free]
PV /dev/vdb6 VG vgn lvm2 [1008.00 MiB / 0 free]
Total: 4 [3.94 GiB] / in use: 4 [3.94 GiB] / in no VG: 0 [0 ]
三.lvm系统快照
1.快照区的创建
[root@server3 ~]# vgdisplay
--- Volume group ---
VG Name vgn
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 10
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 4
Act PV 4
VG Size 3.94 GiB
PE Size 16.00 MiB
Total PE 252
Alloc PE / Size 63 / 1008.00 MiB
Free PE / Size 189 / 2.95 GiB
VG UUID JjHOlH-RdcV-71dR-4wmK-NQ3N-pnRS-1y5dIV
[root@server3 ~]# lvcreate -l 80 -s -n vv /dev/vgn/lvn
Using default stripesize 64.00 KiB.
Reducing COW size 1.25 GiB down to maximum usable size 1.00 GiB.
Logical volume "vv" created.
[root@server3 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vgn/lvn
LV Name lvn
VG Name vgn
LV UUID 3cZBXM-Ef2z-wDLR-Fyxx-TmzD-Payq-BJ6eTm
LV Write Access read/write
LV Creation host, time server3, 2019-01-21 20:32:58 +0800
LV snapshot status source of
vv [active]
LV Status available
# open 1
LV Size 1008.00 MiB
Current LE 63
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 252:0
--- Logical volume ---
LV Path /dev/vgn/vv
LV Name vv
VG Name vgn
LV UUID az5JDg-Njjn-c51c-qdzc-ItEl-pLme-9RHnA7
LV Write Access read/write
LV Creation host, time server3, 2019-01-22 17:40:43 +0800
LV snapshot status active destination for lvn
LV Status available
# open 0
LV Size 1008.00 MiB
Current LE 63
COW-table size 1.00 GiB **快照区的实际容量
COW-table LE 64 **快照区占用的PE数量
Allocated to snapshot 0.00%
Snapshot chunk size 4.00 KiB
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 252:3
挂载查看一下，发现数据与原本的lvn相同
[root@server3 ~]# mkfs.ext4 /dev/vgn/vv
[root@server3 ~]# mount /dev/vgn/vv /mnt/ks/
[root@server3 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/vda3 20243456 3441148 16802308 17% /
devtmpfs 493580 0 493580 0% /dev
tmpfs 508248 84 508164 1% /dev/shm
tmpfs 508248 13568 494680 3% /run
tmpfs 508248 0 508248 0% /sys/fs/cgroup
/dev/vda1 201380 133424 67956 67% /boot
tmpfs 101652 20 101632 1% /run/user/42
tmpfs 101652 0 101652 0% /run/user/0
/dev/mapper/vgn-lvn 3998400 16120 3769816 1% /mnt/lvm
/dev/mapper/vgn-vv 999576 2524 929060 1% /mnt/ks
2.利用快照区复原系统
改变/mnt/lvm中的数据内容，然后再以快照还原
[root@server3 mnt]# df /mnt/lvm/ /mnt/ks/
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vgn-lvn 999576 48280 883304 6% /mnt/lvm
/dev/mapper/vgn-vv 999576 2524 929060 1% /mnt/ks
[root@server3 mnt]# lvdisplay
......
--- Logical volume ---
LV Path /dev/vgn/vv
LV Name vv
VG Name vgn
......
Allocated to snapshot 7.56% 快照已被使用了7.56%
Snapshot chunk size 4.00 KiB
......
[root@server3 /]# mkdir /backup **创建一个目录来备份
[root@server3 mnt]# cd /mnt/ks
[root@server3 ks]# tar -jcvf /backup/lvm.tar.bz2 *
[root@server3 backup]# umount /mnt/ks/ **数据已备份，将快照删除
[root@server3 backup]# lvremove /dev/vgn/vv
Do you really want to remove active logical volume vgn/vv? [y/n]: y
Logical volume "vv" successfully removed
[root@server3 backup]# umount /mnt/lvm/
[root@server3 backup]# mkfs.ext4 /dev/vgn/lvn **将原本的lv格式化
[root@server3 backup]# mount /dev/vgn/lvn /mnt/lvm/
[root@server3 backup]# tar -jxvf /backup/lvm.tar.bz2 -C /mnt/lvm/
[root@server3 backup]# ll /mnt/lvm/
total 16
drwx------ 2 root root 16384 Jan 22 17:45 lost+found
[root@server3 backup]# df /mnt/lvm/
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vgn-lvn 999576 2524 929060 1% /mnt/lvm
发现数据还原
