LOGICAL VOLUME MANAGER

1. Why LVM is required ?

LVM stands for Logical Volume Manager , to resize filesystem’s size online we required LVM partition in Linux. Size of LVM partition can be extended and reduced using the lvextend & lvreduce commands respectively.

2. Is it possible to increase the logical volume on fly ?

YES

3. How to reduce the logical volume ? is it possible to reduce on fly ?
Answer: No.You can’t reduce the logical volume on fly. Here is the steps to reduce the logical volume on redhat Linux.

  •    Un-mount the filesystem
  •    Run e2fsck on the volume device
  •    Reduce the Filesystem.(resize2fs)
  •    Reduce the logical Volume(lvreduce)
  •    Mount the filesystem back for production.

4. What are steps to perform in order to increase the logical volume on fly ?

  •       Extend the logical volume
  •       Increase the Filesystem size
  •       Verify the status using df command or lvs command.

5. .How to rename volume Group ? can we rename the VG on fly ? 
Yes. Its possible to rename the volume group on fly.But the mounted volumes will not reflect the same unless you re-mount the volume with new VG name.
Need to update the /etc/fstab with new VG name to mount the volumes across the system reboot.