Understanding LVM Basics on Linux

1. config Display and manipulate configuration information


2. devtypes Display recognised built-in block device types


3. dumpconfig Display and manipulate configuration information


4. formats List available metadata formats


5. help Display help for commands


6. lvchange Change the attributes of logical volume(s)


7. lvconvert Change logical volume layout


8. lvcreate Create a logical volume


9. lvdisplay Display information about a logical volume


10. lvextend Add space to a logical volume


11. lvmchange With the device mapper, this is obsolete and does nothing.


12. lvmconfig Display and manipulate configuration information


13. lvmdiskscan List devices that may be used as physical volumes


14. lvmsadc Collect activity data


15. lvmsar Create activity report


16. lvreduce Reduce the size of a logical volume


17. lvremove Remove logical volume(s) from the system


18. lvrename Rename a logical volume


19. lvresize Resize a logical volume


20. lvs Display information about logical volumes


21. lvscan List all logical volumes in all volume groups


22. pvchange Change attributes of physical volume(s)


23. pvresize Resize physical volume(s)


24. pvck Check the consistency of physical volume(s)


25. pvcreate Initialize physical volume(s) for use by LVM


26. pvdata Display the on-disk metadata for physical volume(s)


27. pvdisplay Display various attributes of physical volume(s)


28. pvmove Move extents from one physical volume to another


29. lvpoll Continue already initiated poll operation on a logical volume


30. pvremove Remove LVM label(s) from physical volume(s)


31. pvs Display information about physical volumes


32. pvscan List all physical volumes


33. segtypes List available segment types


34. systemid Display the system ID, if any, currently set on this host


35. tags List tags defined on this host


36. vgcfgbackup Backup volume group configuration(s)


37. vgcfgrestore Restore volume group configuration


38. vgchange Change volume group attributes


39. vgck Check the consistency of volume group(s)


40. vgconvert Change volume group metadata format


41. vgcreate Create a volume group


42. vgdisplay Display volume group information


43. vgexport Unregister volume group(s) from the system


44. vgextend Add physical volumes to a volume group


45. vgimport Register exported volume group with system


46. vgmerge Merge volume groups


47. vgmknodes Create the special files for volume group devices in /dev


48. vgreduce Remove physical volume(s) from a volume group


49. vgremove Remove volume group(s)


50. vgrename Rename a volume group


51. vgs Display information about volume groups


52. vgscan Search for all volume groups


53. vgsplit Move physical volumes into a new or existing volume group


54. version Display software and driver version information

check the file system disk space usage and logical volume information: sudo df -h sudo lvs

Get the information about newly added hard disk using the following command: fdisk -l

To create the partition on the second Hard disk, use the following command and follow the “on screen” instructions and change the partition type from Linux to LVM (8e): fdisk /dev/sdb

Identify the already mounted lvm file system type: df -T

Format the newly created partition using the following command: sudo mkfs.ext4 /dev/sdb1

Initialize the newly created partition as a physical volume: sudo pvcreate /dev/sdb1

Check the volume groups using the following command: sudo vgs

Extend the VG (vg_centos6) with new PV (/dev/sdb1): sudo vgextend vg_centos6 /dev/sdb1

Extend the logical volume (lv_root) with all the free space of the VG(vg_centos6): sudo lvextend -l +100%FREE /dev/vg_centos6/lv_root

resize the file-system: sudo resize2fs /dev/vg_centos6/lv_root

Verify the file-system is larger using the following commands: sudo df -h sudo lvs sudo vgs