Linux上LVM创建逻辑卷和LVM快照习题
文章目录
- 1、创建一个至少有两个PV组成的大小为20G的名为testvg的VG；要求PE大小为16MB, 而后在卷组中创建大小为5G的逻辑卷testlv；挂载至/users目录
- 2、新建用户archlinux，要求其家目录为/users/archlinux，而后su切换至archlinux用户，复制/etc/pam.d目录至自己的家目录
- 3、扩展testlv至7G，要求archlinux用户的文件不能丢失
- 4、收缩testlv至3G，要求archlinux用户的文件不能丢失
- 5、对testlv创建快照，并尝试基于快照备份数据，验正快照的功能
1、创建一个至少有两个PV组成的大小为20G的名为testvg的VG；要求PE大小为16MB, 而后在卷组中创建大小为5G的逻辑卷testlv；挂载至/users目录
先查看磁盘大小数据
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
sdc 8:32 0 10G 0 disk
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
为磁盘创建分区，并且分区大小设置为最大，并将分区类型改为8e（linux LVM）
[root@centos ~]# 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): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519):
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@centos ~]# fdisk /dev/sdc
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
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519):
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
现在再查看分区情况
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
创建pv
[root@centos ~]# pvcreate /dev/sdb1 /dev/sdc1
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdc1" successfully created
[root@centos ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- 49.51g 44.00m
/dev/sdb1 lvm2 --- 10.00g 10.00g
/dev/sdc1 lvm2 --- 10.00g 10.00g
创建卷组vg并设置pe大小为16M
[root@centos ~]# vgcreate -s 16M /dev/testvg /dev/sdb1 /dev/sdc1
Volume group "testvg" successfully created
[root@centos ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- 49.51g 44.00m
testvg 2 0 0 wz--n- 19.97g 19.97g
创建逻辑卷lv
[root@centos ~]# lvcreate -L 5G -n testlv testvg
Logical volume "testlv" created.
对逻辑卷进行格式化文件系统
[root@centos ~]# mkfs.ext4 /dev/testvg/testlv
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
327680 inodes, 1310720 blocks
65536 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1342177280
40 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
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
在根下创建目录并且完成挂载
[root@centos ~]# mkdir /users
[root@centos ~]# mount /dev/testvg/testlv /users/
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─testvg-testlv 253:2 0 5G 0 lvm /users
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
2、新建用户archlinux，要求其家目录为/users/archlinux，而后su切换至archlinux用户，复制/etc/pam.d目录至自己的家目录
创建用户
[root@centos ~]# useradd archlinux -d /users/archlinux
我们查看一下新用户的主目录发现正确
[root@centos ~]# cat /etc/passwd|tail -n 1
archlinux:x:1001:1001::/users/archlinux:/bin/bash
登录到新用户上进行复制
[root@centos ~]# su - archlinux
[archlinux@centos ~]$ ls
[archlinux@centos ~]$ cp -a /etc/pam.d/ ./
[archlinux@centos ~]$ ls
pam.d
3、扩展testlv至7G，要求archlinux用户的文件不能丢失
先将逻辑卷进行扩大空间
[root@centos ~]# lvextend -L +2G /dev/testvg/testlv
Size of logical volume testvg/testlv changed from 5.00 GiB (320 extents) to 7.00 GiB (448 extents).
Logical volume testlv successfully resized.
** 将文件系统的大小也进行修改**
[root@centos ~]# resize2fs /dev/testvg/testlv
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/testvg/testlv is mounted on /users; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/testvg/testlv is now 1835008 blocks long.
查看逻辑卷的大小
[root@centos ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 46G 4.5G 42G 10% /
devtmpfs 893M 0 893M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.1M 901M 1% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/sda1 497M 182M 315M 37% /boot
tmpfs 182M 0 182M 0% /run/user/0
/dev/mapper/testvg-testlv 6.8G 23M 6.4G 1% /users
4、收缩testlv至3G，要求archlinux用户的文件不能丢失
先将逻辑卷取消挂载并检查文件系统
[root@centos ~]# umount /dev/testvg/testlv
[root@centos ~]# e2fsck -f /dev/testvg/testlv
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/testvg/testlv: 72/458752 files (0.0% non-contiguous), 67382/1835008 blocks
我们调整文件系统的大小为3G
[root@centos ~]# resize2fs /dev/testvg/testlv 3G
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/testvg/testlv to 786432 (4k) blocks.
The filesystem on /dev/testvg/testlv is now 786432 blocks long.
我们可以暂时将逻辑卷进行挂载查看一下文件系统的大小
[root@centos ~]# mount /dev/testvg/testlv /users/
[root@centos ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 46G 4.5G 42G 10% /
devtmpfs 893M 0 893M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.1M 901M 1% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/sda1 497M 182M 315M 37% /boot
tmpfs 182M 0 182M 0% /run/user/0
/dev/mapper/testvg-testlv 2.9G 16M 2.7G 1% /users
我们取消挂载，并将逻辑卷的大小减去4G
[root@centos ~]# umount /users/
[root@centos ~]# lvreduce -L -4G /dev/testvg/testlv
WARNING: Reducing active logical volume to 3.00 GiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce testlv? [y/n]: y
Size of logical volume testvg/testlv changed from 7.00 GiB (448 extents) to 3.00 GiB (192 extents).
Logical volume testlv successfully resized.
将逻辑卷挂载上之后我们查看文件系统和逻辑卷的大小均为3G
[root@centos ~]# mount /dev/testvg/testlv /users/
[root@centos ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 46G 4.5G 42G 10% /
devtmpfs 893M 0 893M 0% /dev
tmpfs 910M 0 910M 0% /dev/shm
tmpfs 910M 9.1M 901M 1% /run
tmpfs 910M 0 910M 0% /sys/fs/cgroup
/dev/sda1 497M 182M 315M 37% /boot
tmpfs 182M 0 182M 0% /run/user/0
/dev/mapper/testvg-testlv 2.9G 16M 2.7G 1% /users
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─testvg-testlv 253:2 0 3G 0 lvm /users
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
[root@centos ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- 45.59g
swap centos -wi-ao---- 3.88g
testlv testvg -wi-ao---- 3.00g
5、对testlv创建快照，并尝试基于快照备份数据，验正快照的功能
先是在/users/archlinux/目录下创建一个文件1，内容为“abcd”
[root@centos ~]# cd /users/archlinux/
[root@centos archlinux]# ls
pam.d
[root@centos archlinux]# echo "abcd" >1
[root@centos archlinux]# cat 1
abcd
为testlv逻辑卷创建一个快照，名称为snap-data，快照的权限为只读，大小为1G
[root@centos archlinux]# cd
[root@centos ~]# lvcreate -L 1G -s -n snap-data -p r /dev/testvg/testlv
Logical volume "snap-data" created.
创建目录/mnt/snap并且将快照挂载在此目录下
[root@centos ~]# mkdir -p /mnt/snap
[root@centos ~]# mount -o ro /dev/testvg/snap-data /mnt/snap
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
├─testvg-testlv-real 253:3 0 3G 0 lvm
│ ├─testvg-testlv 253:2 0 3G 0 lvm /users
│ └─testvg-snap--data 253:5 0 3G 1 lvm /mnt/snap
└─testvg-snap--data-cow 253:4 0 1G 1 lvm
└─testvg-snap--data 253:5 0 3G 1 lvm /mnt/snap
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
使用lvs查看快照，发现大小为1G，源为testlv
[root@centos ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- 45.59g
swap centos -wi-ao---- 3.88g
snap-data testvg sri-aos--- 1.00g testlv 0.01
testlv testvg owi-aos--- 3.00g
进入到/users/archlinux/目录下修改文件1的内容为“aabbcc”
[root@centos ~]# cd /users/archlinux/
[root@centos archlinux]# echo "aabbcc" > 1
[root@centos archlinux]# cat 1
aabbcc
我们恢复快照
[root@centos archlinux]# cd
[root@centos ~]# umount /dev/testvg/snap-data
[root@centos ~]# umount /dev/testvg/testlv
[root@centos ~]# lvconvert --merge /dev/testvg/snap-data
Merging of volume snap-data started.
testlv: Merged: 100.0%
[root@centos ~]# mount /dev/testvg/testlv /users/
[root@centos ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 49.5G 0 part
├─centos-root 253:0 0 45.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─testvg-testlv 253:2 0 3G 0 lvm /users
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sdd 8:48 0 10G 0 disk
sr0 11:0 1 4G 0 rom
我们查看我们之前改过的文件1，发现内容现在为“abcd”，证明是快照前的内容
[root@centos ~]# cd /users/archlinux/
[root@centos archlinux]# ls
1 pam.d
[root@centos archlinux]# cat 1
abcd