Manage Logical Volumes

Question 1

What is the order to create a logical volume?

Answer 1

Hard Disks (/dev/sda, /dev/sdb, /dev/sdc)
Partitions (/dev/sda1, /dev/sdb1, /dev/sdc1)
Physical Volume (/dev/sda1, /dev/sdb1, /dev/sdc1)
Volume Group (datavg)
Logical Volume (datalv)
File System (datafs)

Question 2

What are the steps to creating a logical volume?

Answer 2

1. Create Partition
   fdisk /dev/sdc
   n - new partition
   p - primary partition type
   default - partition number
   default - first sector
   default - last sector
   p - for checking work
   t - change partition system id
   L - to find LVM
   8e=LVM
   8e - then enter
   w - write to partition table
2. Create Physical Volume
   pvcreate /dev/sdc1 - creates physical volume
   pvdisplay - displays physical volume
3. Create Volume Group
   vgcreate redhat_vg - Creates volume group
   assigned to /dev/sdc1
   vgdisplay redhat_vg - Displays volume group
4. Create Logical Volumes
   lvcreate -n redhat_lv –size 100G redhat_vg
   lvdisplay - displays logical volume
5. Assign File System
   mkfs.xfs /dev/mapper/redhat_vg/redhat_lv
6. Mount Directory
   mkdir /redhat
   mount /dev/mapper/redhat_vg/redhat_lv
   /redhat

Question 3

What are the steps to extend disk space using LVM?

Answer 3

1. Partition Disk
   fdisk /dev/sdc
   n - new partition
   p - primary partition type
   default - partition number
   default - first sector
   default - last sector
   p - for checking work
   t - change partition system id
   L - to find LVM
   8e=LVM
   8e - then enter
   w - write to partition table
2. Create Physical Volume
   pvcreate /dev/sdd1
3. Extend
   vgextend redhat_vg /dev/sdd1
   lvextend -L+1024M (or -l+100%FREE)
   /dev/mapper/redhat_vg-redhat_lv
   xfs_growfs /dev/mapper/redhat_vg-redhat_lv