Linux LVM Mirroring (RAID -1 ) Part I

This post I am going to show how to mirror a logical volume:

[root@test ~]# df -TH /oracle
Filesystem    Type     Size   Used  Avail Use% Mounted on
/dev/mapper/oracle-oracle_lv
              ext4     1.1G   1.1G      0 100% /oracle
[root@test ~]#

Before mirroring:

[root@test ~]# lvdisplay -m /dev/oracle/oracle_lv

  --- Logical volume ---

  LV Name                /dev/oracle/oracle_lv

  VG Name                oracle

  LV UUID                O9W6go-l2AC-0XP9-GvLw-tL2C-bjeI-YoWmDG

  LV Write Access        read/write

  LV Status              available

  # open                 1

  LV Size                1.00 GiB

  Current LE             256

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

  --- Segments ---

  Logical extent 0 to 255:

    Type                linear

    Physical volume     /dev/sdc

    Physical extents    0 to 255

Initializing and adding a new disk to the VG Oracle:

[root@test ~]# pvcreate /dev/sdb

  Writing physical volume data to disk "/dev/sdb"

  Physical volume "/dev/sdb" successfully created

[root@test ~]# vgextend /dev/oracle /dev/sdb

  Volume group "oracle" successfully extended

[root@test ~]#