使用逻辑卷管理灵活存储|LAMP小白的小窝

使用逻辑卷管理灵活存储

作者:LAMP小白点击:1645 发布日期:2014-06-02 01:54:49 返回列表

查看LVM定义

物理分区或磁盘是LVM的第一构建块。这些可以是分区、完整磁盘、raid集或SAN磁盘。

物理卷是LVM所使用的基础“物理”存储。这通常是块设备、例如分区或完整磁盘。设备必须初始化为LVM物理卷，才能与LVM结合使用。

卷组是存储池，由一个或多个卷组成。

物理区块是物理卷中存储的小型数据区块，用作LVM存储的后端。

逻辑区块映射到物理区块，构成LVM存储的前端。默认情况下，每个逻辑区块映射到一个物理区块，启用某些选项将更改此映射。例如：镜像会导致每个逻辑区块映射到两个物理区块。

逻辑卷是逻辑区块组。逻辑卷可以像硬盘驱动器分区一样使用。

使用命令行工具实施LVM存储

准备物理卷

[root@MIO-02 ~]# fdisk -cu /dev/vda

Command (m for help): p

Disk /dev/vda: 8589 MB, 8589934592 bytes
16 heads, 63 sectors/track, 16644 cylinders, total 16777216 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 identifier: 0x0005b3b1

Device Boot Start End Blocks Id System
/dev/vda1 * 2048 411647 204800 83 Linux
/dev/vda2 411648 8800255 4194304 8e Linux LVM
/dev/vda3 8800256 10897407 1048576 82 Linux swap / Solaris
/dev/vda4 10897408 16777215 2939904 5 Extended
/dev/vda5 10899456 12996607 1048576 83 Linux
/dev/vda6 12998656 14022655 512000 83 Linux

Command (m for help): n
First sector (14024704-16777215, default 14024704):
Using default value 14024704
Last sector, +sectors or +size{K,M,G} (14024704-16777215, default 16777215): +500M

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@MIO-02 ~]# partx /dev/vda
[root@MIO-02 ~]# pvcreate /dev/vda7
Physical volume "/dev/vda7" successfully created

pvcreate用于初始化分区(或其他物理设备)，使其作为物理卷与LVM结合使用。直接在物理卷中创建用于存储LVM配置数据的表头。

创建卷组

创建和使用新逻辑卷

[root@MIO-02 ~]# vgcreate new01 /dev/vda7
Volume group "new01" successfully created

创建和使用新逻辑卷
[root@MIO-02 ~]# lvcreate -n newname -L 480M new01
Logical volume "newname" created
[root@MIO-02 ~]# mkfs.ext4 /dev/new01/newname
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
122880 inodes, 491520 blocks
24576 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67633152
60 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409

Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@MIO-02 ~]# mkdir /newname_mount
[root@MIO-02 ~]# mount /dev/new01/newname /newname_mount/

查看LVM状态信息

[root@MIO-02 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/vda7
VG Name new01
PV Size 500.00 MiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 124
Free PE 4
Allocated PE 120
PV UUID akffb5-5ODW-L75m-dkoh-U6Tq-w3Bd-6Jkvtu

--- Physical volume ---
PV Name /dev/vda2
VG Name vg_mio02
PV Size 4.00 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 1023
Free PE 0
Allocated PE 1023
PV UUID pwEb4L-7MOu-fSos-2JPF-nEPM-kjKo-wOGDnM

--- Physical volume ---
PV Name /dev/vda5
VG Name vg_mio02
PV Size 1.00 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 255
Free PE 0
Allocated PE 255
PV UUID HhGzm6-TP8A-udjb-533a-auDC-jI0f-7LbnP1

[root@MIO-02 ~]# vgdisplay
--- Volume group ---
VG Name new01
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 496.00 MiB
PE Size 4.00 MiB
Total PE 124
Alloc PE / Size 120 / 480.00 MiB
Free PE / Size 4 / 16.00 MiB
VG UUID gYCRi5-TzBB-ZVtv-yABc-jruQ-zSLM-LkvBp0

--- Volume group ---
VG Name vg_mio02
System ID
Format lvm2
Metadata Areas 2
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 2
Act PV 2
VG Size 4.99 GiB
PE Size 4.00 MiB
Total PE 1278
Alloc PE / Size 1278 / 4.99 GiB
Free PE / Size 0 / 0
VG UUID ZDh2Ol-B4th-z6JS-Ngg7-RIdM-DTEP-fDc0Nk

[root@MIO-02 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/new01/newname
LV Name newname
VG Name new01
LV UUID c321R4-NtsL-flM4-daTT-iD1q-lxTE-5CCi7i
LV Write Access read/write
LV Creation host, time MIO-02, 2014-06-01 23:14:56 +0800
LV Status available
# open 1
LV Size 480.00 MiB
Current LE 120
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1

--- Logical volume ---
LV Path /dev/vg_mio02/LogVol00
LV Name LogVol00
VG Name vg_mio02
LV UUID wO3M2x-hYEH-cdIt-GmO6-M683-1dCd-AReKb4
LV Write Access read/write
LV Creation host, time MIO-02, 2014-05-14 22:47:19 +0800
LV Status available
# open 1
LV Size 4.99 GiB
Current LE 1278
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

扩展逻辑卷和ext4文件系统

[root@MIO-02 ~]# lvextend -l 124 /dev/new01/newname
Extending logical volume newname to 496.00 MiB
Logical volume newname successfully resized
[root@MIO-02 ~]# resize2fs -p /dev/new01/newname
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/new01/newname is mounted on /newname_mount; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 2
Performing an on-line resize of /dev/new01/newname to 507904 (1k) blocks.
The filesystem on /dev/new01/newname is now 507904 blocks long.

减小文件系统和逻辑卷

[root@MIO-02 ~]# umount /newname_mount/
[root@MIO-02 ~]# fsck -f /dev/new01/newname
fsck from util-linux-ng 2.17.2
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/mapper/new01-newname: 11/126976 files (0.0% non-contiguous), 26534/507904 blocks
[root@MIO-02 ~]# resize2fs -p /dev/new01/newname 200M
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/new01/newname to 204800 (1k) blocks.
Begin pass 3 (max = 62)
Scanning inode table XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/new01/newname is now 204800 blocks long.

[root@MIO-02 ~]# lvreduce -L 200M /dev/new01/newname
WARNING: Reducing active logical volume to 200.00 MiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce newname? [y/n]: y
Reducing logical volume newname to 200.00 MiB
Logical volume newname successfully resized

扩展和缩减卷组

扩展卷组
[root@MIO-02 ~]# pvcreate /dev/vda8
Physical volume "/dev/vda8" successfully created
[root@MIO-02 ~]# vgextend new01 /dev/vda8
Volume group "new01" successfully extended
[root@MIO-02 ~]# vgdisplay

缩减卷组
[root@MIO-02 /]# pvmove /dev/vda8
No data to move for new01
[root@MIO-02 /]# vgdisplay
--- Volume group ---
VG Name new01
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 592.00 MiB
PE Size 4.00 MiB
Total PE 148
Alloc PE / Size 25 / 100.00 MiB
Free PE / Size 123 / 492.00 MiB
VG UUID x1Xz0H-DICG-Zjzc-g7rY-aHzO-xdfR-ex1H2U

--- Volume group ---
VG Name vg_mio02
System ID
Format lvm2
Metadata Areas 2
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 2
Act PV 2
VG Size 4.99 GiB
PE Size 4.00 MiB
Total PE 1278
Alloc PE / Size 1278 / 4.99 GiB
Free PE / Size 0 / 0
VG UUID ZDh2Ol-B4th-z6JS-Ngg7-RIdM-DTEP-fDc0Nk

[root@MIO-02 /]# vgreduce new01 /dev/vda8
Removed "/dev/vda8" from volume group "new01"
[root@MIO-02 /]# vgdisplay new01
--- Volume group ---
VG Name new01
System ID
Format lvm2
Metadata Areas 1
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 1
Act PV 1
VG Size 496.00 MiB
PE Size 4.00 MiB
Total PE 124
Alloc PE / Size 25 / 100.00 MiB
Free PE / Size 99 / 396.00 MiB
VG UUID x1Xz0H-DICG-Zjzc-g7rY-aHzO-xdfR-ex1H2U

创建快照便于数据备份

[root@MIO-02 /]# lvcreate -s -n snaplv -L 20M /dev/new01/lv01
Logical volume "snaplv" created
[root@MIO-02 /]# mkdir /snapdir
[root@MIO-02 /]# mount -o ro /dev/new01/snaplv /snapdir/
[root@MIO-02 /]# cd /snapdir/
[root@MIO-02 snapdir]# ll
total 13
-rw-r--r--. 1 root root 0 Jun 1 23:46 123
drwx------. 2 root root 12288 Jun 1 23:46 lost+found
[root@MIO-02 snapdir]# lvs /dev/new01/snaplv
LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert
snaplv new01 swi-aos-- 20.00m lv01 0.06
[root@MIO-02 snapdir]# umount /snapdir/
umount: /snapdir: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@MIO-02 snapdir]# cd /
[root@MIO-02 /]# umount /snapdir/
[root@MIO-02 /]# lvremove /dev/new01/snaplv
Do you really want to remove active logical volume snaplv? [y/n]: y
Logical volume "snaplv" successfully removed
[root@MIO-02 /]#

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