Linux存儲實驗二：LVM操作
Linux存儲實驗二：RAID操作
http://www.2cto.com/os/201303/195811.html
(1) 創建LVM
步驟一：再新建5塊10MB SCSI的硬盤
這一步和上一步制作raid的操作是一樣的，請參見上一篇
步驟二：用4塊硬盤做raid5+1hostspare
mdadm --create --auto=yes /dev/md1 --level=5 --raid-devices=4 --spare-device=1 /dev/sdc{5,6,7,8,9}
注意：這次我們創建raid起名為/dev/md1(上次為/dev/md0)
步驟三：查看RAID組成情況
[root@compute-0 mnt]# mdadm --detail /dev/md*
mdadm: /dev/md does not appear to be an md device
/dev/md0: # 上次RAID實驗創建的
Version : 1.2
Creation Time : Fri Mar 22 04:41:39 2013
Raid Level : raid5
Array Size : 480768 (469.58 MiB 492.31 MB)
Used Dev Size : 160256 (156.53 MiB 164.10 MB)
Raid Devices : 4
Total Devices : 5
Persistence : Superblock is persistent
Update Time : Fri Mar 22 05:44:28 2013
State : clean
Active Devices : 4
Working Devices : 5
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Name : compute-0:0 (local to host compute-0)
UUID : d81cdfce:03d33c89:ffe54067:44e19b55
Events : 18
Number Major Minor RaidDevice State
0 8 21 0 active sync /dev/sdb5
1 8 22 1 active sync /dev/sdb6
2 8 23 2 active sync /dev/sdb7
5 8 24 3 active sync /dev/sdb8
4 8 25 - spare /dev/sdb9
/dev/md1: #這次我們新創建的
Version : 1.2
Creation Time : Fri Mar 22 04:42:44 2013
Raid Level : raid5
Array Size : 480768 (469.58 MiB 492.31 MB)
Used Dev Size : 160256 (156.53 MiB 164.10 MB)
Raid Devices : 4
Total Devices : 5
Persistence : Superblock is persistent
Update Time : Fri Mar 22 05:44:31 2013
State : clean
Active Devices : 4
Working Devices : 5
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Name : compute-0:1 (local to host compute-0)
UUID : da3b02e6:b77652b6:3688ad25:9c34dabc
Events : 18
Number Major Minor RaidDevice State
0 8 37 0 active sync /dev/sdc5
1 8 38 1 active sync /dev/sdc6
2 8 39 2 active sync /dev/sdc7
5 8 40 3 active sync /dev/sdc8
4 8 41 - spare /dev/sdc9
步驟四：將RAID轉換為物理卷(即：PV)
[root@compute-0 mnt]# pvscan # 先掃描一下是否有現存的物理卷
No matching physical volumes found
[root@compute-0 mnt]# pvcreate /dev/md1 # 創建物理卷
Writing physical volume data to disk "/dev/md1"
Physical volume "/dev/md1" successfully created
[root@compute-0 mnt]# pvscan # 查看一下
PV /dev/md1 lvm2 [469.50 MiB]
Total: 1 [469.50 MiB] / in use: 0 [0 ] / in no VG: 1 [469.50 MiB]
[root@compute-0 mnt]#
步驟五：新建一個邏輯卷組(即：VG)
[root@compute-0 mnt]# vgscan
Reading all physical volumes. This may take a while...
No volume groups found
[root@compute-0 mnt]# vgcreate -s 16M houqdvg /dev/md1
# 注：-s 表示PE的大小 houqdvg表示創建的邏輯卷組的名稱
Volume group "houqdvg" successfully created
[root@compute-0 mnt]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "houqdvg" using metadata type lvm2
[root@compute-0 mnt]# vgdisplay
--- Volume group ---
VG Name houqdvg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 464.00 MiB
PE Size 16.00 MiB # PE的大小
Total PE 29 # 該邏輯卷組裡面PE的總量
Alloc PE / Size 0 / 0
Free PE / Size 29 / 464.00 MiB
VG UUID vBlcd2-qt6Y-Bt1D-v63K-oIJv-a3Hm-tPzoue
[root@compute-0 mnt]#
步驟六：建立邏輯卷(即：LV)，並建立文件系統
[root@compute-0 mnt]# lvcreate -l 29 -n houqdlv houqdvg
注： -l 後面指定的是PE的個數
-L 後面指定的是按照大小來建
-n 後面指定創建的邏輯卷的名字
Logical volume "houqdlv" created
[root@compute-0 mnt]# lvdisplay
--- Logical volume ---
LV Name /dev/houqdvg/houqdlv
# 注：以後使用該邏輯卷一定要用這個/dev/houqdvg/houqdlv全名
VG Name houqdvg
LV UUID T0L4cu-dqNC-PRHz-QQ3u-0ubi-VAWe-YquY7t
LV Write Access read/write
LV Status available
# open 0
LV Size 464.00 MiB
Current LE 29
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 6144
Block device 253:0
[root@compute-0 mnt]# mkfs -t ext3 /dev/houqdvg/houqdlv # 創建文件系統
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=512 blocks, Stripe width=1536 blocks
118784 inodes, 475136 blocks
23756 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67633152
58 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 21 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@compute-0 mnt]#
步驟七：掛載邏輯卷，先用mount命令掛載，然後定義在/etc/fstab中
[root@compute-0 mnt]# mkdir -p /mnt/lvm
[root@compute-0 mnt]# mount /dev/houqdvg/houqdlv /mnt/lvm/ # 掛載
[root@compute-0 mnt]# mount # 查看所有掛載
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
vmware-vmblock on /var/run/vmblock-fuse type fuse.vmware-vmblock (rw,nosuid,nodev,default_permissions,allow_other)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
nfsd on /proc/fs/nfsd type nfsd (rw)
/dev/mapper/houqdvg-houqdlv on /mnt/lvm type ext3 (rw) # 我們掛載的
[root@compute-0 mnt]# vi /etc/fstab # 設置每次開機自動掛載
# /etc/fstab
# Created by anaconda on Wed Feb 27 13:44:14 2013
#
# 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
#
UUID=4626a1a8-2485-4f14-a09a-6eef0a6c720e / ext4 defaults 1 1
UUID=74b536a0-9407-4214-98ed-11ba8b2d389c /boot ext4 defaults 1 2
UUID=a90215c9-be26-4884-bd0e-3799c7ddba7b 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
/dev/houqdvg/houqdlv /mnt/lvm ext3 defaults 1 2
(2) LVM擴容
步驟一：將第一個RAID轉換為物理卷
[root@compute-0 mnt]# pvcreate /dev/md0
Writing physical volume data to disk "/dev/md0"
Physical volume "/dev/md0" successfully created
[root@compute-0 mnt]#
步驟二：將物理卷加入到現有的邏輯卷組中
[root@compute-0 mnt]# vgextend houqdvg /dev/md0
# 將/dev/md0加入到houqdvg這個卷組中了
Volume group "houqdvg" successfully extended
步驟三：查看邏輯卷組空間大小
[root@compute-0 mnt]# vgdisplay
--- Volume group ---
VG Name houqdvg
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 928.00 MiB
PE Size 16.00 MiB
Total PE 58 # 注：這裡PE的總量增加了一倍，
Alloc PE / Size 29 / 464.00 MiB
Free PE / Size 29 / 464.00 MiB # 注：未分配的還有29個PE
VG UUID vBlcd2-qt6Y-Bt1D-v63K-oIJv-a3Hm-tPzoue
步驟四：將邏輯卷空間增加200M並查看邏輯卷空間大小
[root@compute-0 mnt]# lvdisplay
--- Logical volume ---
LV Name /dev/houqdvg/houqdlv
VG Name houqdvg
LV UUID T0L4cu-dqNC-PRHz-QQ3u-0ubi-VAWe-YquY7t
LV Write Access read/write
LV Status available
# open 1
LV Size 464.00 MiB # 這是未增加之前的
Current LE 29
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 6144
Block device 253:0
[root@compute-0 mnt]# lvresize -L +200M /dev/houqdvg/houqdlv
# 注：-L 後面直接指定大小，或者也可以用 -l+PE的個數來指定
Rounding up size to full physical extent 208.00 MiB
Extending logical volume houqdlv to 672.00 MiB
Logical volume houqdlv successfully resized
[root@compute-0 mnt]# lvdisplay
--- Logical volume ---
LV Name /dev/houqdvg/houqdlv
VG Name houqdvg
LV UUID T0L4cu-dqNC-PRHz-QQ3u-0ubi-VAWe-YquY7t
LV Write Access read/write
LV Status available
# open 1
LV Size 672.00 MiB # 可以看到該邏輯卷的確增加了200M
Current LE 42
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 6144
Block device 253:0
步驟五：將文件系統增加200M
[root@compute-0 mnt]# df /mnt/lvm/
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/houqdvg-houqdlv
460144 10543 425845 3% /mnt/lvm
# 注：我們已經將邏輯卷/dev/houqdvg/houqdlv擴容了但是這裡還是400多M
[root@compute-0 mnt]# resize2fs /dev/houqdvg/houqdlv
# 注：這裡才是真正的對文件系統擴容，實際block塊的大小是不會增加的，只是分組數增多了，響應的空間就大了
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/houqdvg/houqdlv is mounted on /mnt/lvm; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 3
Performing an on-line resize of /dev/houqdvg/houqdlv to 688128 (1k) blocks.
The filesystem on /dev/houqdvg/houqdlv is now 688128 blocks long.
[root@compute-0 mnt]# df /mnt/lvm/
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/houqdvg-houqdlv
666415 10789 621236 2% /mnt/lvm
# 注：現在查看已經擴容
OK，這周的實驗就先到這裡吧，下周有可能會根據這兩周做的實驗，講一下關於系統快照的知識，看情況再說吧。
