Linux Logical Volume Management Operations: Difference between revisions
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* <span id='Creating_a_Logical_Volume'></span>[[lvcreate]] - creates a logical volume in an existing volume group. | * <span id='Creating_a_Logical_Volume'></span>[[lvcreate]] - creates a logical volume in an existing volume group. | ||
* <span id='Extending_a_Logical_Volume'></span>[[lvresize]] - resize a logical volume. | |||
===Renaming a Logical Volume=== | ===Renaming a Logical Volume=== |
Revision as of 15:20, 23 May 2017
External
- https://www.howtogeek.com/howto/40702/how-to-manage-and-use-lvm-logical-volume-management-in-ubuntu/
Internal
Overview
Logical volume management commands can be issued from the lvm console, or as standalone commands. For example:
lvm> lvs
produces identical results to
lvs
Inventory of Devices that May Be Used as Physical Volumes
lvmdiskscan
Example:
[root@rhel-test ~]# lvmdiskscan /dev/rhel_rhel-test/swap [ 820.00 MiB] /dev/sda1 [ 500.00 MiB] /dev/rhel_rhel-test/root [ 6.67 GiB] /dev/sda2 [ 7.51 GiB] LVM physical volume /dev/sdb [ 2.00 GiB] 3 disks 1 partition 0 LVM physical volume whole disks 1 LVM physical volume
The output specifies which device is already a LVM Physical Volume
To see only the existing Physical Volumes (devices that have Volume Groups on them)
lvmdiskscan -l
Physical Volume Operations
Information about Physical Volumes
- pvs - provides information about physical volumes available on the system.
- pvscan - scans all disks for physical volumes.
- pvdisplay - provides details about a specific physical volume.
Physical Volume Management Operations
- pvcreate - initializes a physical volume(s) for use by LVM.
- pvchange - changes attributes of a physical volume.
- pvresize - resizes a disk or partition in use.
- pvmove - moves physical extents from one physical volume to another.
- pvck - checks the consistency of the physical volume metadata.
- pvremove - removes a physical volume.
Volume Group Operations
Information about Volume Groups
Volume Group Management Operations
- vgcreate - create a volume group.
- vgextend - add Physical Volumes to a Volume Group.
- vgreduce - removes one or more unused physical volumes from a volume group.
Logical Volume Operations
Information about Logical Volumes
- lvs - provides information about logical volumes available on the system.
- lvdisplay - displays attributes of a logical volume.
- lvscan - scans all known volume groups or all supported LVM block devices in the system for defined Logical Volumes.
Logical Volume Management Operations
- lvcreate - creates a logical volume in an existing volume group.
- lvresize - resize a logical volume.
Renaming a Logical Volume
lvm lvm> lvrename VolGroup00 LogVol05numbercat lv05
Remove a Logical Volume
Gather statistics on the free space before removing, and also on the size of the logical volume to be removed:
vgs
lvs
Unmount the volume if necessary (or shutdown the service that is using it, as it is the case with Docker):
umount /dev/VolGroup00/MyLV1
Remove the logical volume with lvremove.
The command has a "dry run mode" (-t):
lvremove /dev/<VG_name>/<LV_name>
lvremove -t /dev/<VG_name>/<LV_name>
Example:
[root@rhel-test lvm]# lvremove -t /dev/rhel_rhel-test/docker-pool TEST MODE: Metadata will NOT be updated and volumes will not be (de)activated. Do you really want to remove active logical volume docker-pool? [y/n]: y Logical volume "docker-pool" successfully removed
This command actually removes it:
lvremove [-v] /dev/VolGroup00/MyLV1
Shrinking the Filesystem and the Logical Volume
This is the simple case, it will only work if the logical volume *does not* contain a partition table:
fsadm
or
umount lvm_partition resize2fs /dev/vg/lv newSize lvresize -L disksize /dev/vg/lv resize2fs /dev/vg/lv