Hello Friend's, In this session i am going to tell all about LVM (LOGICAL VOLUME MANAGEMENT) ,
========================================================================
I) How to create a Volume Group (VG).
II) How to create a Logical Volume (LV) and mount the file system.
III) How to add a disk to a Volume Group
IV) How to increase the size of a logical volume without OnlineJFS
V) How to remove a Logical Volume
VI) How to reduce the size of a logical volume without OnlineJFS (advanced JFS)
VII) How to remove a disk from a volume group
VIII) How to remove a volume group
IX) How to increase the primary swap
X) How to create a secondary boot disk LVM Mirroring
XI) How to mirror a logical volume
XII) How to unmirror a logical volume
XIII) How to create a mirrored boot disk
XIV) How to mirror a logical volume on a specific physical volume Physical Volume Group
XV) How to create a Physical Volume Group (PVG)
XVI) How to use PVG to mirror logical volumes on specific physical volumes
========================================================================
Step:1 To check the device (hda , sda) by using fdisk.check the new partition
[root@trash3can /]# fdisk -l
[root@trash3can ~]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1020 8193118+ 83 Linux
/dev/sda2 1021 1275 2048287+ 83 Linux
Step:2 Create the partation
[root@trash3can ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 1305.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
>> m command for help
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
>> n command for add a new partition
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p >>press p for primary partition
Partition number (1-4): 3
First cylinder (1276-1305, default 1276):
Using default value 1276
Last cylinder or +size or +sizeM or +sizeK (1276-1305, default 1305): +100M
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Selected partition 4
First cylinder (1289-1305, default 1289):
Using default value 1289
Last cylinder or +size or +sizeM or +sizeK (1289-1305, default 1305): +100M
>> p for print the partition table
Command (m for help): p
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1020 8193118+ 83 Linux
/dev/sda2 1021 1275 2048287+ 83 Linux
/dev/sda3 1276 1288 104422+ 83 Linux
/dev/sda4 1289 1301 104422+ 83 Linux
>>w write table to disk and exit
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.
Syncing disks.
>> to change the partation id by pressing the t command
Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): L
0 Empty 1e Hidden W95 FAT1 80 Old Minix bf Solaris
1 FAT12 24 NEC DOS 81 Minix / old Lin c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 82 Linux swap / So c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 83 Linux c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c7 Syrinx
5 Extended 41 PPC PReP Boot 85 Linux extended da Non-FS data
6 FAT16 42 SFS 86 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set de Dell Utility
8 AIX 4e QNX4.x 2nd part 88 Linux plaintext df BootIt
9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
>> 8e Linux LVM
Hex code (type L to list codes): 8e
Changed system type of partition 3 to 8e (Linux LVM)
Command (m for help): t
Partition number (1-4): 4
Hex code (type L to list codes): 8e
Changed system type of partition 4 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1020 8193118+ 83 Linux
/dev/sda2 1021 1275 2048287+ 83 Linux
/dev/sda3 1276 1288 104422+ 8e Linux LVM
/dev/sda4 1289 1301 104422+ 8e Linux LVM
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.
Syncing disks.
Step:3 Check the partation y using fdisk -l command
[root@trash3can ~]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1020 8193118+ 83 Linux
/dev/sda2 1021 1275 2048287+ 83 Linux
/dev/sda3 1276 1288 104422+ 8e Linux LVM
/dev/sda4 1289 1301 104422+ 8e Linux LVM
[root@node1 ~]# cat /proc/partitions
major minor #blocks name
8 0 10485760 sda
8 1 8193118 sda1
8 2 2048287 sda2
8 16 1048576 sdb
8 17 409626 sdb1
8 18 409657 sdb2
8 19 224910 sdb3
********************************phycial volumes************************************
Step:4 Now we are creating the phycial volume (/dev/sda3,/dev/sda4).one or more phycial volume creates the volume group.
[root@trash3can ~]# pvcreate /dev/sda3 /dev/sda4
Physical volume "/dev/sda3" successfully created
Physical volume "/dev/sda4" successfully created
[root@trash3can ~]#
Step:5 To check and verify the phycial volume by using the pvdisplay.
[root@trash3can ~]# pvscan
[root@trash3can ~]# pvdisplay
"/dev/sda3" is a new physical volume of "101.98 MB"
--- NEW Physical volume ---
PV Name /dev/sda3
VG Name
PV Size 101.98 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID nvle6H-L3cv-EFl3-2F70-EXRM-05bs-8iPQ7h
"/dev/sda4" is a new physical volume of "101.98 MB"
--- NEW Physical volume ---
PV Name /dev/sda4
VG Name
PV Size 101.98 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID Vbt35c-iOr3-5lIA-0U7q-O0Qb-uC2n-zdKTcz
Note : Now you can see , We created the two PV ("/dev/sda3" , "/dev/sda4") Successfully
"/dev/sda3" is a new physical volume of "101.98 MB"
PV Name /dev/sda3
PV Size 101.98 MB
"/dev/sda4" is a new physical volume of "101.98 MB"
PV Name /dev/sda4
PV Size 101.98 MB
[root@trash3can ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 lvm2 -- 1.95G 1.95G
/dev/sda3 lvm2 -- 54.91M 54.91M
[root@trash3can ~]#
[root@trash3can ~]#
[root@trash3can ~]# pvscan
PV /dev/sda2 lvm2 [1.95 GB]
PV /dev/sda3 lvm2 [54.91 MB]
Total: 2 [2.01 GB] / in use: 0 [0 ] / in no VG: 2 [2.01 GB]
********************************Volume group *************************************
Step:6 Now we are creating the volume group by using two phycial volume ("/dev/sda3" , "/dev/sda4")and we need to give the volume group name(vg).
[root@trash3can ~]# vgcreate vg /dev/sda3 /dev/sda4
Volume group "vg" successfully created
Here volume name is vg
Step:7 To check and verify the volume group by using the vgdisplay.
[root@trash3can ~]# vgs
VG #PV #LV #SN Attr VSize VFree
my_volume_group 2 0 0 wz--n- 2.00G 2.00G
[root@trash3can ~]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "my_volume_group" using metadata type lvm2
[root@trash3can ~]# vgdisplay
--- Volume group ---
VG Name vg
System ID
Format lvm2
Metadata Areas 2
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 2
Act PV 2
VG Size 200.00 MB
PE Size 4.00 MB
Total PE 50
Alloc PE / Size 0 / 0
Free PE / Size 50 / 200.00 MB
VG UUID nMofQi-kjDL-B8uS-zG0s-90Gk-s2Fe-mqjCv2
Note :
VG Name vg
VG Access read/write
VG Status resizable
VG Size 200.00 MB(+100 M + 100M)
PE Size 4.00 MB
*******************************Logical volume *************************************
Step:8 Now we will create the logical volume.Here logical volume name is lv and size is +50M
[root@trash3can ~]# lvcreate -L +50M -n lv /dev/vg
Rounding up size to full physical extent 52.00 MB
Logical volume "lv" created
L- length of the LV
n- used to define the name of the lv
Step:9 to check and verify wheather lv created or not.
[root@trash3can ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
my_logical_volume my_volume_group -wi-a- 500.00M
[root@trash3can ~]# lvscan
ACTIVE '/dev/my_volume_group/my_logical_volume' [500.00 MB] inherit
[root@trash3can ~]#
[root@trash3can ~]# lvdisplay
--- Logical volume ---
LV Name /dev/vg/lv
VG Name vg
LV UUID I33kZN-j74r-yu6w-xx0R-23Sc-pTRg-n5uG4I
LV Write Access read/write
LV Status available
# open 0
LV Size 52.00 MB
Current LE 13
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
Note :
LV Name /dev/vg/lv
LV Size 52.00 MB
Block device 253:0(100+100+50)
******************************Create the file system *********************************
Step:10 Create the file system by using the mkfs command.
[root@trash3can ~]# mkfs.ext3 /dev/vg/lv
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
13328 inodes, 53248 blocks
2662 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=54525952
7 block groups
8192 blocks per group, 8192 fragments per group
1904 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961
Writing inode tables: done
Creating journal (4096 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.
Step:11 Create the directory to mount the File system .
[root@trash3can ~]# mkdir LVM
Step:12
[root@trash3can ~]# mount /dev/vg/lv LVM/
Step:13 Check and verify
[root@trash3can ~]# df -HTP
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 ext3 8.2G 5.8G 2.0G 75% /
/dev/sda2 ext3 2.1G 37M 1.9G 2% /swap
tmpfs tmpfs 531M 0 531M 0% /dev/shm
/dev/mapper/vg-lv ext3 53M 5.1M 45M 11% /root/LVM
*****************************LVM mounting****************************************
Step:14 We need to add the entries in /etc/fstab to make the parmanent entries
[root@trash3can ~]# vim /etc/fstab
/dev/mapper/vg-lv /root/LVM ext3 defaults 0 0
[root@trash3can ~]# mount -a
[root@node1 ~]# mount |grep lv
/dev/mapper/vg-lv on /root/LVM type ext3 (rw)
[root@trash3can ~]# cp /etc/passwd LVM/
[root@trash3can ~]# ll LVM/
total 14
drwx------ 2 root root 12288 Dec 28 08:22 lost+found
-rw-r--r-- 1 root root 1791 Dec 28 09:20 passwd
Step:15 Reboot the system to verify that the file system is automatically mounted after boot with df-HTP command
[root@trash3can ~]# df -HTP
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda1 ext3 8.2G 5.8G 2.0G 75% /
/dev/sda2 ext3 2.1G 37M 1.9G 2% /swap
tmpfs tmpfs 531M 0 531M 0% /dev/shm
/dev/mapper/vg-lv ext3 53M 5.1M 45M 11% /root/LVM
***********************************LV extend**************************************
LVM Management (LV extend)
grom volumes
Growing volumes
a) lvextend can grow the logical volumes.
b)resize2fs can grow ext3 File system online and offline
>>>Extend <<<
Step:16 Extend the lv with 100 M size
[root@trash3can ~]# lvextend -L +100M /dev/vg/lvStep:17 Still size is 53M
Extending logical volume lv to 152.00 MB
Logical volume lv successfully resized
[root@trash3can ~]# lvdisplay
--- Logical volume ---
LV Name /dev/vg/lv
VG Name vg
LV UUID I33kZN-j74r-yu6w-xx0R-23Sc-pTRg-n5uG4I
LV Write Access read/write
LV Status available
# open 0
LV Size 152.00 MB >>>
Current LE 38
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
[root@trash3can ~]# df -HTP
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vg-lv ext3 53M 5.1M 45M 11% /root/LVM
Step:18 We need to run the commad to make the changes onine
[root@trash3can ~]# resize2fs -p /dev/vg/lv
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg/lv is mounted on /root/LVM; on-line resizing required
Performing an on-line resize of /dev/vg/lv to 155648 (1k) blocks.
The filesystem on /dev/vg/lv is now 155648 blocks long.
[root@trash3can ~]# df -h LVM/
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg-lv 148M 5.3M 135M 4% /root/LVM
Now size has been changed (148M)
*********************************************************************************
EXTRA Info
Step:19 Shrinking volume must be done offline umount
[root@trash3can ~]# umount LVM/
Requires a file ssytem check e2fsck
[root@trash3can ~]# e2fsck -F /dev/vg/lv
e2fsck 1.39 (29-May-2006)
/dev/vg/lv: clean, 12/36176 files, 9945/155648 blocks
*********************************************************************************
Now I am adding one more disk in FS(/dev/sd5)
[root@trash3can ~]# pvcreate /dev/sda5
Physical volume "/dev/sda5" successfully created
[root@trash3can ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name vg
PV Size 1.95 GB / not usable 287.50 KB
Allocatable yes
PE Size (KByte) 4096
Total PE 500
Free PE 462
Allocated PE 38
PV UUID vDEBXN-PSdT-Xqfv-T0fL-856Z-jB4d-aM7xks
--- Physical volume ---
PV Name /dev/sda3
VG Name vg
PV Size 101.98 MB / not usable 1.98 MB
Allocatable yes
PE Size (KByte) 4096
Total PE 25
Free PE 25
Allocated PE 0
PV UUID 8EogKA-i6H6-VrbB-YwLb-N0D1-ARlN-Wry1gI
"/dev/sda5" is a new physical volume of "54.88 MB"
--- NEW Physical volume ---
PV Name /dev/sda5
VG Name
PV Size 54.88 MB
Allocatable NO
PE Size (KByte) 0
Total PE 0
Free PE 0
Allocated PE 0
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