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Logical Volume Manager

LVM Commands
###########


>> First we need to create Physical Volume. PV is chunks of 4MBs
>> Then create Volume Group using this PV.
>> THen create Logical Volume.

Creating PV:

[root@localhost ~]# pvcreate /dev/vdb5 /dev/vdc1 /dev/vdb6 /dev/vdc2
  Physical volume "/dev/vdb5" successfully created.
  Physical volume "/dev/vdc1" successfully created.
  Physical volume "/dev/vdb6" successfully created.
  Physical volume "/dev/vdc2" successfully created.


pvdisplay

  --- NEW Physical volume ---
  PV Name               /dev/vdc1
  VG Name              
  PV Size               2.00 GiB
  Allocatable           NO
  PE Size               0  
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               gDI14y-m6Af-DAek-0xdv-bZEs-4wVd-GJcH68
  
  "/dev/vdb5" is a new physical volume of "1.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/vdb5
  VG Name              
  PV Size               1.00 GiB
  Allocatable           NO
  PE Size               0  
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               NrBHJ6-JVBz-Z6UI-jpBi-OS9A-elWq-M5Ndnu
  
  "/dev/vdc2" is a new physical volume of "1.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/vdc2
  VG Name              
  PV Size               1.00 GiB
  Allocatable           NO
  PE Size               0  
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               le8iAi-wADA-QKGx-nUU8-NC5v-U8ts-cgBNsK
  
  "/dev/vdb6" is a new physical volume of "1.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/vdb6
  VG Name              
  PV Size               1.00 GiB
  Allocatable           NO
  PE Size               0  
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               1BVXOS-Ws83-HC4d-Jmmh-rw5d-VnuS-cwj2HK


Volume Group Creation:
######################

vgcreate

[root@localhost ~]# vgcreate -v myvg-group /dev/vdb5 /dev/vdc1
    Wiping internal VG cache
    Wiping cache of LVM-capable devices
    Wiping signatures on new PV /dev/vdb5.
    Wiping signatures on new PV /dev/vdc1.
    Adding physical volume '/dev/vdb5' to volume group 'myvg-group'
    Adding physical volume '/dev/vdc1' to volume group 'myvg-group'
    Archiving volume group "myvg-group" metadata (seqno 0).
    Creating volume group backup "/etc/lvm/backup/myvg-group" (seqno 1).
  Volume group "myvg-group" successfully created


[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               myvg-group
  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               2.99 GiB
  PE Size               4.00 MiB
  Total PE              766
  Alloc PE / Size       0 / 0  
  Free  PE / Size       766 / 2.99 GiB
  VG UUID               B2bMFI-covb-RpUc-I3U9-FI08-T7ym-FGfOBn
  
  --- Volume group ---
  VG Name               cl
  System ID            
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               19.00 GiB
  PE Size               4.00 MiB
  Total PE              4863
  Alloc PE / Size       4863 / 19.00 GiB
  Free  PE / Size       0 / 0  
  VG UUID               JPKYIf-gxbw-CV72-sOK0-dc4e-Zy9Y-jCZcdj
 
 
 
  Creating the Logical Volume
  ############################
 
  [root@localhost ~]# lvcreate -L 1.5G -n myLV1 myvg-group
  Logical volume "myLV1" created.

  Viewing the Logical Volume
  ##########################
 
  root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/myvg-group/myLV1
  LV Name                myLV1
  VG Name                myvg-group
  LV UUID                xQZu1c-tQ0S-jlYo-Dquz-16VY-HuIQ-xOcucI
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-10-21 03:14:01 -0400
  LV Status              available
  # open                 0
  LV Size                1.50 GiB
  Current LE             384
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2
  
  --- Logical volume ---
  LV Path                /dev/cl/swap
  LV Name                swap
  VG Name                cl
  LV UUID                3TzTXH-7jCc-akY7-ZT9V-VZsi-Sc8L-q8A2zt
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-10-19 06:13:30 -0400
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
  
  --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                us1RfD-IlME-Kg5F-RWed-Z0Cc-LgDC-ucLdVP
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-10-19 06:13:30 -0400
  LV Status              available
  # open                 1
  LV Size                17.00 GiB
  Current LE             4351
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

 
 
 
[root@localhost ~]# mkfs.ext4 /dev/myvg-group/myLV1
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
98304 inodes, 393216 blocks
19660 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=402653184
12 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912

Allocating group tables: done                           
Writing inode tables: done                           
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
 
 
 
  LV extending
  ############
 
[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               myvg-group
  System ID            
  Format                lvm2
  Metadata Areas        2
  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                2
  Act PV                2
  VG Size               2.99 GiB
  PE Size               4.00 MiB
  Total PE              766
  Alloc PE / Size       384 / 1.50 GiB
  Free  PE / Size       382 / 1.49 GiB
  VG UUID               B2bMFI-covb-RpUc-I3U9-FI08-T7ym-FGfOBn

 
lvextend -L +1.49G /dev/myvg-group/myLV1
 
[root@localhost ~]# lvextend -L +1.49G /dev/myvg-group/myLV1
  Rounding size to boundary between physical extents: 1.49 GiB.
  Size of logical volume myvg-group/myLV1 changed from 1.50 GiB (384 extents) to 2.99 GiB (766 extents).
  Logical volume myvg-group/myLV1 successfully resized.

mkfs of resized LV
##################
 
  [root@localhost ~]# resize2fs /dev/myvg-group/myLV1
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/myvg-group/myLV1 is mounted on /mnt; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/myvg-group/myLV1 is now 784384 blocks long.


[root@localhost ~]# df -h
Filesystem                     Size  Used Avail Use% Mounted on
/dev/mapper/cl-root             17G  951M   17G   6% /
devtmpfs                       234M     0  234M   0% /dev
tmpfs                          245M     0  245M   0% /dev/shm
tmpfs                          245M  4.4M  240M   2% /run
tmpfs                          245M     0  245M   0% /sys/fs/cgroup
/dev/vda1                     1014M  138M  877M  14% /boot
tmpfs                           49M     0   49M   0% /run/user/0
/dev/mapper/myvg--group-myLV1  3.0G  4.5M  2.8G   1% /mnt


Now the LV is increased to 3GB from 1.5 GB


Now there is no space in the VG:

Now if we need to increase the space of the LV..We need to first extent the VG


  Physical volume "/dev/vdb6" successfully created.
 

[root@localhost ~]# vgextend myvg-group /dev/vdb6
  Volume group "myvg-group" successfully extended


root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               myvg-group
  System ID            
  Format                lvm2
  Metadata Areas        3
  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                3
  Act PV                3
  VG Size               3.99 GiB
  PE Size               4.00 MiB
  Total PE              1021
  Alloc PE / Size       766 / 2.99 GiB
  Free  PE / Size       255 / 1020.00 MiB
  VG UUID               B2bMFI-covb-RpUc-I3U9-FI08-T7ym-FGfOBn
  
  --- Volume group ---
  VG Name               cl
  System ID            
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               19.00 GiB
  PE Size               4.00 MiB
  Total PE              4863
  Alloc PE / Size       4863 / 19.00 GiB
  Free  PE / Size       0 / 0  
  VG UUID               JPKYIf-gxbw-CV72-sOK0-dc4e-Zy9Y-jCZcdj

 
 
[root@localhost ~]# lvextend -L +1020M /dev/myvg-group/myLV1
  Size of logical volume myvg-group/myLV1 changed from 2.99 GiB (766 extents) to 3.99 GiB (1021 extents).
  Logical volume myvg-group/myLV1 successfully resized.
 
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/myvg-group/myLV1
  LV Name                myLV1
  VG Name                myvg-group
  LV UUID                xQZu1c-tQ0S-jlYo-Dquz-16VY-HuIQ-xOcucI
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-10-21 03:14:01 -0400
  LV Status              available
  # open                 1
  LV Size                3.99 GiB
  Current LE             1021
  Segments               3
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2

 
  Physical volume "/dev/vdc2" successfully created.
 
Now we are going to extend the / root VG ie 'cl'
 
[root@localhost ~]# vgextend cl /dev/vdc2
  Volume group "cl" successfully extended

    
  --- Volume group ---
  VG Name               cl
  System ID            
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               19.99 GiB
  PE Size               4.00 MiB
  Total PE              5118
  Alloc PE / Size       4863 / 19.00 GiB
  Free  PE / Size       255 / 1020.00 MiB
  VG UUID               JPKYIf-gxbw-CV72-sOK0-dc4e-Zy9Y-jCZcdj
 
  Now check the filesystem of cl VG
 
  cat /etc/fstab | grep cl-root
 
  [root@localhost ~]# cat /etc/fstab | grep cl-root
/dev/mapper/cl-root     /                       xfs     defaults        0 0

 
its xfs.

Now extent the LV

 --- Logical volume ---
  LV Path                /dev/cl/root
  LV Name                root
  VG Name                cl
  LV UUID                us1RfD-IlME-Kg5F-RWed-Z0Cc-LgDC-ucLdVP
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2017-10-19 06:13:30 -0400
  LV Status              available
  # open                 1
  LV Size                17.99 GiB
  Current LE             4606
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0


[root@localhost ~]# lvextend -L +1020M /dev/cl/root
  Size of logical volume cl/root changed from 17.00 GiB (4351 extents) to 17.99 GiB (4606 extents).
  Logical volume cl/root successfully resized.
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# xfs_growfs /dev/cl/root
meta-data=/dev/mapper/cl-root    isize=512    agcount=4, agsize=1113856 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=4455424, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 4455424 to 4716544
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# df -h
Filesystem                     Size  Used Avail Use% Mounted on
/dev/mapper/cl-root             18G  951M   18G   6% /
devtmpfs                       234M     0  234M   0% /dev
tmpfs                          245M     0  245M   0% /dev/shm
tmpfs                          245M  4.4M  240M   2% /run
tmpfs                          245M     0  245M   0% /sys/fs/cgroup
/dev/vda1                     1014M  138M  877M  14% /boot
tmpfs                           49M     0   49M   0% /run/user/0
/dev/mapper/myvg--group-myLV1  3.0G  4.5M  2.8G   1% /mnt
[root@localhost ~]#

 
  To reduce the created LV
  #########################
 
  [root@localhost ~]# df -h
Filesystem                     Size  Used Avail Use% Mounted on
/dev/mapper/cl-root             18G  951M   18G   6% /
devtmpfs                       234M     0  234M   0% /dev
tmpfs                          245M     0  245M   0% /dev/shm
tmpfs                          245M  4.4M  240M   2% /run
tmpfs                          245M     0  245M   0% /sys/fs/cgroup
/dev/vda1                     1014M  138M  877M  14% /boot
tmpfs                           49M     0   49M   0% /run/user/0
/dev/mapper/myvg--group-myLV1  3.0G  4.5M  2.8G   1% /mnt
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# umount /dev/mapper/myvg--group-myLV1
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/cl-root   18G  951M   18G   6% /
devtmpfs             234M     0  234M   0% /dev
tmpfs                245M     0  245M   0% /dev/shm
tmpfs                245M  4.4M  240M   2% /run
tmpfs                245M     0  245M   0% /sys/fs/cgroup
/dev/vda1           1014M  138M  877M  14% /boot
tmpfs                 49M     0   49M   0% /run/user/0
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# e2fsck -f /dev/myvg-group/myLV1
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/myvg-group/myLV1: 11/196608 files (9.1% non-contiguous), 21692/784384 blocks

[root@localhost ~]# resize2fs /dev/myvg-group/myLV1 2G
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/myvg-group/myLV1 to 524288 (4k) blocks.
The filesystem on /dev/myvg-group/myLV1 is now 524288 blocks long.

[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# lvreduce -L 2G /dev/myvg-group/myLV1
  WARNING: Reducing active logical volume to 2.00 GiB.
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce myvg-group/myLV1? [y/n]: y
  Size of logical volume myvg-group/myLV1 changed from 3.99 GiB (1021 extents) to 2.00 GiB (512 extents).
  Logical volume myvg-group/myLV1 successfully resized.

 
  [root@localhost ~]# mount /dev/myvg-group/myLV1 /mnt
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# df -h
Filesystem                     Size  Used Avail Use% Mounted on
/dev/mapper/cl-root             18G  951M   18G   6% /
devtmpfs                       234M     0  234M   0% /dev
tmpfs                          245M     0  245M   0% /dev/shm
tmpfs                          245M  4.4M  240M   2% /run
tmpfs                          245M     0  245M   0% /sys/fs/cgroup
/dev/vda1                     1014M  138M  877M  14% /boot
tmpfs                           49M     0   49M   0% /run/user/0
/dev/mapper/myvg--group-myLV1  2.0G  4.5M  1.9G   1% /mnt


[root@localhost ~]# lvscan
  ACTIVE            '/dev/myvg-group/myLV1' [2.00 GiB] inherit
  ACTIVE            '/dev/cl/swap' [2.00 GiB] inherit
  ACTIVE            '/dev/cl/root' [17.99 GiB] inherit
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# vgscan
  Reading volume groups from cache.
  Found volume group "myvg-group" using metadata type lvm2
  Found volume group "cl" using metadata type lvm2
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# pvscan
  PV /dev/vdb5   VG myvg-group      lvm2 [1020.00 MiB / 1016.00 MiB free]
  PV /dev/vdc1   VG myvg-group      lvm2 [2.00 GiB / 0    free]
  PV /dev/vdb6   VG myvg-group      lvm2 [1020.00 MiB / 1020.00 MiB free]
  PV /dev/vda2   VG cl              lvm2 [19.00 GiB / 0    free]
  PV /dev/vdc2   VG cl              lvm2 [1020.00 MiB / 0    free]
  Total: 5 [23.98 GiB] / in use: 5 [23.98 GiB] / in no VG: 0 [0   ]

 
  [root@localhost ~]# lvremove /dev/myvg-group/myLV1
Do you really want to remove active logical volume myvg-group/myLV1? [y/n]: y
  Logical volume "myLV1" successfully removed
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# vgscan
  Reading volume groups from cache.
  Found volume group "myvg-group" using metadata type lvm2
  Found volume group "cl" using metadata type lvm2
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# vgremove /dev/myvg-group
  Volume group "myvg-group" successfully removed

[root@localhost ~]#
[root@localhost ~]# pvremove /dev/vdb5 /dev/vdc1 /dev/vdb6
  Labels on physical volume "/dev/vdb5" successfully wiped.
  Labels on physical volume "/dev/vdc1" successfully wiped.
  Labels on physical volume "/dev/vdb6" successfully wiped.
 

 
Commands
########

   10  fdisk -l
   11  fdisk /dev/vdb
   12  partprobe /dev/vdb
   13  mkfs.ext4 /dev/vdb1
   14  mount /dev/vdb1 /mnt/
   15  cd
   16  umount /mnt/
   17  fdisk -
   18  fdisk -l
   19  fdisk /dev/vdb
   20  partprobe /dev/vdb
   21  fdisk -l
   22  free -m
   23  poweroff
   24  passwd
   25  sed -i 's/192.168.10.181/192.168.10.188/g' /etc/sysconfig/network-scripts/ifcfg-eth0
   26  poweroff
   27  hostname -i
   28  ifconfig | grep inet
   29  ip -a
   30  cat /etc/hosts
   31  cat /etc/sysconfig/network
   32  w
   33  ps aux | grep pts/0
   34  w
   35  fdisk -l
   36  fdisk -l | grep disk
   37  fdisk -l | grep -i disk
   38  fdisk -l
   40  fdisk /dev/vda1
   42  fdisk -l
   43  fdisk /dev/vdb
   44  fdisk -l
   45  fdisk /dev/vdb
   46  partprobe
   48  fdisk -l /dev/vdb
   49  mkfs.ext4 /dev/vbd1
   50  mkfs.ext4 /dev/vdb1
   51  fdisk -l
   52  mkfs.ext4 /dev/vdb2
   53  mkfs.ext4 /dev/vdb3
   54  fdisk -l
   55  mount /dev/vdb1 /mnt
   57  mount
   58  cd /mnt
   59  touch jino
   60  cd
   61  fdisk /mnt/jino
   62  fdisk -l /mnt/jino
   64  vi /etc/fstab
   65  cat /etc/fstab
   66  mount -a
   68  fdisk -l
   69  fdisk /dev/vdc
   70  partprobe /dev/vdc
   72  fdisk -l
   73  fdisk /dev/vdb
   74  partprobe /dev/vdb
   76  fdisk -l
   77  pvcreate /dev/vdb5 /dev/vdc1 /dev/vdb6 /dev/vdc2
   78  pvdisplay
   79  vgcreate -v myvg-group /dev/vdb5 /dev/vdc1
   80  vgdisplay
   81  lvcreate -L 1.5G -n myLV1 myvg-group
   82  lvdisplay
   83  mkfs.ext4 /dev/myvg-group/myLV1
   84  mount /dev/myvg-group/myLV1
   85  #mount /dev/myvg-group/myLV1
   87  umount /dev/vdb1
   88  mount /dev/myvg-group/myLV1 /mnt
   90  lvdisplay
   91  vgdisplay
   93  lvdisplay
   94  vgdisplay
   95  lvextend -L +1.49G /dev/myvg-group/myLV1
   96  resize2fs /dev/myvg-group/myLV1
   98  fdisk -l
   99  vgextent myvg-group /dev/vdb6
  100  vgextend myvg-group /dev/vdb6
  101  vgdisplay
  102  lvextend -L +1020M /dev/myvg-group/myLV1
  104  lvdisplay
  105  fdisk -l
  106  pvdisplay
  107  vgextend cl /dev/vdc2
  108  vgdisplay
  109  cat /etc/fstab | grep cl-root
  110  lvdisplay
  111  lvextend -L +1020M /dev/cl/root
  112  xfs_growfs /dev/cl/root
  114  lvdisplay
  116  umount /dev/mapper/myvg--group-myLV1
  118  e2fsck -f /dev/myvg-group/myLV1
  119  resize2fs /dev/myvg-group/myLV1 2G
  120  lvreduce -L 2G /dev/myvg-group/myLV1
  122  mount /dev/myvg-group/myLV1
  123  mount /dev/myvg-group/myLV1 /mnt
  125  lvdisplay
  126  vgdisplay
  129  history
  132  lvscan
  133  vgscan
  134  pvscan
  136  umount /dev/myvg-group/myLV1
  138  lvscan
  139  lvremove /dev/myvg-group/myLV1
  140  vgscan
  141  vgremove /dev/myvg-group
  142  pvremove /dev/vdb5 /dev/vdc1 /dev/vdb6

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