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Chapter 4. Basic logical volume management

With LVM, you can do the following tasks:

  • Create new logical volumes to extend storage capabilities of your system
  • Extend existing volumes and thin pools to accommodate growing data
  • Rename volumes for better organization
  • Reduce volumes to free up unused space
  • Safely remove volumes when they are no longer needed
  • Activate or deactivate volumes to control the system’s access to its data

4.1. Overview of logical volume features

With the Logical Volume Manager (LVM), you can manage disk storage in a flexible and efficient way that traditional partitioning schemes cannot offer. Below is a summary of key LVM features that are used for storage management and optimization.

Concatenation
Concatenation involves combining space from one or more physical volumes into a singular logical volume, effectively merging the physical storage.
Striping
Striping optimizes data I/O efficiency by distributing data across multiple physical volumes. This method enhances performance for sequential reads and writes by allowing parallel I/O operations.
RAID
LVM supports RAID levels 0, 1, 4, 5, 6, and 10. When you create a RAID logical volume, LVM creates a metadata subvolume that is one extent in size for every data or parity subvolume in the array.
Thin provisioning
Thin provisioning enables the creation of logical volumes that are larger than the available physical storage. With thin provisioning, the system dynamically allocates storage based on actual usage instead of allocating a predetermined amount upfront.
Snapshots
With LVM snapshots, you can create point-in-time copies of logical volumes. A snapshot starts empty. As changes occur on the original logical volume, the snapshot captures the pre-change states through copy-on-write (CoW), growing only with changes to preserve the state of the original logical volume.
Caching
LVM supports the use of fast block devices, such as SSD drives as write-back or write-through caches for larger slower block devices. Users can create cache logical volumes to improve the performance of their existing logical volumes or create new cache logical volumes composed of a small and fast device coupled with a large and slow device.

4.2. Creating logical volumes

LVM provides a flexible approach to handling disk storage by abstracting the physical layer into logical volumes that can be created and adjusted based on your needs.

4.2.1. Creating a linear (thick) logical volume

With linear logical volumes (LVs), you can merge multiple physical storage units into one virtual storage space. You can easily expand or reduce linear LVs to accommodate the data requirements.

Prerequisites

  • Administrative access.
  • The lvm2 package is installed.
  • The volume group is created. For more information, see Creating LVM volume group.

Procedure

  1. List the names of volume groups and their size: 

    # vgs -o vg_name,vg_size

  VG              VSize
  VolumeGroupName 30.75g

  2. Create a linear LV: 

    # lvcreate --name LogicalVolumeName --size VolumeSize VolumeGroupName

    Replace LogicalVolumeName with the name of the LV. Replace VolumeSize with the size for the LV. If no size suffix is provided the command defaults to MB. Replace VolumeGroupName with the name of the volume group.

Verification

  • Verify that the linear LV is created: 

    # lvs -o lv_name,seg_type

  LV                   Type
  LogicalVolumeName    linear

Additional resources

  • The vgs(8), lvs(8), lvcreate(8) man pages

4.2.2. Creating a striped logical volume

With striped logical volume (LV), you can distribute the data across multiple physical volumes (PVs), potentially increasing the read and write speed by utilizing the bandwidth of multiple disks simultaneously.

When creating a striped LV, it is important to consider the stripe number and size. The stripe number is the count of PVs across which data is distributed. Increasing the stripe number can enhance performance by utilizing multiple disks concurrently. Stripe size is the size of the data chunk written to each disk in the stripe set before moving to the next disk and is specified in kilobytes (KB). The optimal stripe size depends on your workload and the filesystem block size. The default is 64KB and can be adjusted.

Prerequisites

  • Administrative access.

Procedure

  1. List the names of volume groups and their size: 

    # vgs -o vg_name,vg_size

  VG              VSize
  VolumeGroupName 30.75g

  2. Create a striped LV: 

    # lvcreate --stripes NumberOfStripes --stripesize StripeSize --size LogicalVolumeSize --name LogicalVolumeName VolumeGroupName

    Replace NumberOfStripes with the number of stripes. Replace StripeSize with the stripe size in kilobytes. The --stripesize is not a required option. If you do not specify the stripe size it defaults to 64KB. Replace LogicalVolumeName with the name of the LV. Replace VolumeGroupName with the name of the volume group.

Verification

  • Verify that the striped LV is created: 

    # lvs -o lv_name,seg_type

  LV                   Type
  LogicalVolumeName    striped

Additional resources

  • The vgs(8) lvs(8), lvcreate(8) man pages

4.2.3. Creating a RAID logical volume

RAID logical volumes enable you to use multiple disks for redundancy and performance. LVM supports various RAID levels, including RAID0, RAID1, RAID4, RAID5, RAID6, and RAID10.

With LVM you can create striped RAIDs (RAID0, RAID4, RAID5, RAID6), mirrored RAID (RAID1), or a combination of both (RAID10).

RAID 4, RAID 5, and RAID 6 offer fault tolerance by storing parity data that can be used to reconstruct lost information in case of a disk failure.

When creating RAID LVs, place each stripe on a separate PV. The number of stripes equals to the number of PVs that should be in the volume group (VG).

Table 4.1. Minimal RAID configuration requirements
RAID levelTypeParityMinimum number of devicesMinimum stripe number

RAID0

Striping

None

2

2

RAID1

Mirroring

None

2

-

RAID4

Striping

Uses first device to store parity

3

2

RAID5

Striping

Uses an extra device to store parity

3

2

RAID6

Striping

Uses two extra devices to store parity

5

3

RAID10

Striping and mirroring

None

4

2

Prerequisites

  • Administrative access.

Procedure

  1. List the names of volume groups and their size: 

    # vgs -o vg_name,vg_size

  VG              VSize
  VolumeGroupName 30.75g

  2. Create a RAID LV:

    • To create a striped raid, use: 

      # lvcreate --type raidlevel --stripes NumberOfStripes --stripesize StripeSize --size Size --name LogicalVolumeName VolumeGroupName

      Replace level with the RAID level 0, 4, 5, or 6. Replace NumberOfStripes with the number of stripes. Replace StripeSize with the stripe size in kilobytes. Replace Size with the size of the LV. Replace LogicalVolumeName with the name of the LV.

    • To create a mirrored RAID, use: 

      # lvcreate --type raid1 --mirrors MirrorsNumber --size Size --name LogicalVolumeName VolumeGroupName

      Replace MirrorsNumber with the number of mirrors. Replace Size with the size of the LV. Replace LogicalVolumeName with the name of the LV.

    • To create a mirrored and striped RAID, use: 

      # lvcreate --type raid10 --mirrors MirrorsNumber --stripes NumberOfStripes --stripesize StripeSize --size Size --name LogicalVolumeName VolumeGroupName

      Replace MirrorsNumber with the number of mirrors. Replace NumberOfStripes with the number of stripes. Replace StripeSize with the stripe size in kilobytes. Replace Size with the size of the LV. Replace LogicalVolumeName with the name of the LV.

Verification

  • Verify that the RAID LV is created: 

    # lvs -o lv_name,seg_type

  LV                   Type
  LogicalVolumeName    raid0

Additional resources

  • lvmraid(7), vgs(8), lvs(8), lvcreate(8) man pages

4.2.4. Creating a thin logical volume

Under thin provisioning, physical extents (PEs) from a volume group (VG) are allocated to create a thin pool with a specific physical size. Logical volumes (LVs) are then allocated from this thin pool based on a virtual size, not limited by the pool’s physical capacity. With this, the virtual size of each thin LV can exceed the actual size of the thin pool leading to over-provisioning, when the collective virtual sizes of all thin LVs surpasses the physical capacity of the thin pool. Therefore, it is essential to monitor both logical and physical usage closely to avoid running out of space and outages.

Thin provisioning optimizes storage efficiency by allocating space as needed, lowering initial costs and improving resource utilization. However, when using thin LVs, beware of the following drawbacks:

  • Improper discard handling can block the release of unused storage space, causing full allocation of the space over time.
  • Copy on Write (CoW) operation can be slower on file systems with snapshots.
  • Data blocks can be intermixed between multiple file systems leading to random access limitations.

Prerequisites

Procedure

  1. List the names of volume groups and their size: 

    # vgs -o vg_name,vg_size

  VG              VSize
  VolumeGroupName 30.75g

  2. Create a thin pool: 

    # lvcreate --type thin-pool --size PoolSize --name ThinPoolName VolumeGroupName

    Replace PoolSize with the maximum amount of disk space the thin pool can use. Replace ThinPoolName with the name for the thin pool. Replace VolumeGroupName with the name of the volume group.

  3. Create a thin LV: 

    # lvcreate --type thin --virtualsize MaxVolumeSize --name ThinVolumeName --thinpool ThinPoolName VolumeGroupName

    Replace MaxVolumeSize with the maximum size the volume can grow to within the thin pool. Replace ThinPoolName with the name for the thin pool. Replace VolumeGroupName with the name of the volume group.

    Note

    You can create other thin LVs within the same thin pool.

Verification

  • Verify that the thin LV is created: 

    # lvs -o lv_name,seg_type
  LV                Type
  ThinPoolName      thin-pool
  ThinVolumeName    thin

Additional resources

  • The lvs(8), lvcreate(8) man pages

4.2.5. Creating a VDO logical volume

VDO logical volumes (LVs) use the Virtual Data Optimizer (VDO) technology to enhance storage efficiency. VDO LVs have both a virtual size and a physical size. The virtual size refers to the total amount of storage presented to users and applications. The physical size is the actual amount of physical storage allocated from the VG and consumed by the VDO pool.

The virtual size of a VDO LV is generally larger than the physical size of the VDO pool, making it over-provisioned. Due to over-provisioning the physical space in the VDO pool needs to be closely monitored and extended when needed.

A VDO LV and a VDO pool are created as a pair, and always exist as a pair.

Prerequisites

  • Administrative access.

Procedure

  1. List the names of volume groups and their size: 

    # vgs -o vg_name,vg_size

  VG              VSize
  VolumeGroupName 30.75g

  2. Create a VDO LV: 

    # lvcreate --type vdo --virtualsize VolumeSize --size PhysicalPoolSize --name VDOVolumeName --vdopool VDOPoolName VolumeGroupName

    Replace the VolumeSize with the size for the volume. Replace the PhysicalPoolSize with the size for the pool. Replace the VDOVolumeName with the name for your VDO volume. Replace the VDOPoolName with the name for your VDO pool. Replace VolumeGroupName with the name of the volume group.

Verification

  • Verify that the VDO LV is created: 

    # lvs -o name,seg_type,size

  LV            Type     LSize
  VDOPoolName   vdo-pool   5.00g
  VDOVolumeName vdo        5.00g

Additional resources

  • The vgs(8), lvs(8), lvcreate(8) man pages

4.3. Resizing logical volumes

With Logical Volume Manager (LVM), you can resize logical volumes (LVs) as needed without affecting the data stored on them.

4.3.1. Extending a linear logical volume

You can extend linear (thick) LVs and their snapshots with the lvextend command.

Prerequisites

  • Administrative access.

Procedure

  1. Ensure your volume group has enough space to extend your LV: 

    # lvs -o lv_name,lv_size,vg_name,vg_size,vg_free
  LV                   LSize   VG              VSize  VFree
  LogicalVolumeName    1.49g   VolumeGroupName 30.75g 29.11g

  2. Extend the linear LV and resize the file system: 

    # lvextend --size +AdditionalSize --resizefs VolumeGroupName/LogicalVolumeName

    Replace AdditionalSize with how much space to add to the LV. The default unit of measurement is megabytes, but you can specify other units. Replace VolumeGroupName with the name of the volume group. Replace LogicalVolumeName with the name of the thin volume.

Verification

  • Verify that the linear LV is extended: 

    # lvs -o lv_name,lv_size
  LV                   LSize
  NewLogicalVolumeName 6.49g

4.3.2. Extending a thin logical volume

You can extend the thin logical volume (LV) with the lvextend command.

Prerequisites

  • Administrative access.

Procedure

  1. Ensure the thin pool has enough space for the data you plan to add: 

    # lvs -o lv_name,lv_size,data_percent

  LV                LSize   Data%
  MyThinPool        20.10g  3.21
  ThinVolumeName     1.10g  4.88

  2. Extend the thin LV and resize the file system: 

    # lvextend --size +AdditionalSize --resizefs VolumeGroupName/ThinVolumeName

    Replace AdditionalSize with how much space to add to the LV. The default unit of measurement is megabytes, but you can specify other units. Replace VolumeGroupName with the name of the volume group. Replace ThinVolumeName with the name of the thin volume.

Verification

  • Verify the thin LV is extended: 

    # lvs -o lv_name,lv_size,data_percent

  LV                LSize   Data%
  MyThinPool        20.10g  3.21
  ThinVolumeName     6.10g  0.43

4.3.3. Extending a thin pool

The virtual size of thin logical volumes can exceed the physical capacity of the thin pool resulting in over-provisioning. To prevent running out of space, you must monitor and periodically extend the capacity of the thin pool.

The data_percent metric indicates the percentage of the allocated data space that the thin pool currently uses. The metadata_percent metric reflects the percentage of space used for storing metadata, which is essential for managing the mappings within the thin pool.

Monitoring these metrics is vital to ensure efficient storage management and to avoid capacity issues.

LVM provides the option to manually extend the data or metadata capacity as needed. Alternatively, you can enable monitoring and automate the expansion of your thin pool.

4.3.3.1. Manually extending a thin pool

Logical Volume Manager (LVM) provides the option to manually extend the data segment, the metadata segment, or the thin pool.

4.3.3.1.1. Extending a thin pool

You can use the lvextend command to extend the thin pool.

Prerequisites

  • Administrative access.

Procedure

  1. Display the data and metadata space used: 

    # lvs -o lv_name,seg_type,data_percent,metadata_percent

  LV                Type      Data%  Meta%
  ThinPoolName      thin-pool 97.66  26.86
  ThinVolumeName    thin      48.80

  2. Extend the thin pool: 

    # lvextend -L Size VolumeGroupName/ThinPoolName

    Replace Size with the new size for your thin pool. Replace VolumeGroupName with the name of the volume group. Replace ThinPoolName with the name of the thin pool.

    The data size will be extended. The metadata size will be extended if necessary.

Verification

  • Verify that the thin pool is extended: 

    # lvs -o lv_name,seg_type,data_percent,metadata_percent

  LV                Type      Data%  Meta%
  ThinPoolName      thin-pool 24.41  16.93
  ThinVolumeName    thin      24.41

Additional resources

  • The lvs(8), lvextend(8) man pages
  • lvs -o help
4.3.3.1.2. Extending a thin pool data segment

You can use the lvextend command to extend the data_percent segment.

Prerequisites

  • Administrative access.

Procedure

  1. Display the data_percent segment: 

    # lvs -o lv_name,seg_type,data_percent

  LV                Type      Data%
  ThinPoolName      thin-pool 93.87

  2. Extend the data_percent segment: 

    # lvextend -L Size VolumeGroupName/ThinPoolName_tdata

    Replace Size with the size for your data segment. Replace VolumeGroupName with name of the volume group. Replace ThinPoolName with the name of the thin pool.

Verification

  • Verify that the data_percent segment is extended: 

    # lvs -o lv_name,seg_type,data_percent

  LV                Type      Data%
  ThinPoolName      thin-pool 40.23

Additional resources

  • The lvs(8), lvextend(8) man pages
  • lvs -o help
4.3.3.1.3. Extending a thin pool metadata segment

You can use the lvextend command to extend the metadata_percent segment.

Prerequisites

  • Administrative access.

Procedure

  1. Display the metadata_percent segment: 

    # lvs -o lv_name,seg_type,metadata_percent

  LV                Type      Meta%
  ThinPoolName      thin-pool 75.00

  2. Extend the metadata_percent segment: 

    # lvextend -L Size VolumeGroupName/ThinPoolName_tmeta

    Replace Size with the size for your metadata segment. Replace VolumeGroupName with name of the volume group. Replace ThinPoolName with the name of the thin pool.

Verification

  • Verify that the metadata_percent segment is extended: 

    # lvs -o lv_name,seg_type,metadata_percent

  LV                Type      Meta%
  ThinPoolName      thin-pool 0.19

Additional resources

  • The lvs(8), lvextend(8) man pages
  • lvs -o help

4.3.3.2. Automatically extending a thin pool

You can automate the expansion of your thin pool by enabling monitoring and setting the thin_pool_autoextend_threshold and the thin_pool_autoextend_percent configuration parameters.

Prerequisites

  • Administrative access.

Procedure

  1. Check if the thin pool is monitored: 

    # lvs -o lv_name,vg_name,seg_monitor

  LV                VG              Monitor
  ThinPoolName      VolumeGroupName not monitored

  2. Enable thin pool monitoring with the dmeventd daemon: 

    # lvchange --monitor y VolumeGroupName/ThinPoolName

    Replace VolumeGroupName with the name of the volume group. Replace ThinPoolName with the name of the thin pool.

  3. As the root user, open the /etc/lvm/lvm.conf file in an editor of your choice.

  4. Uncomment the thin_pool_autoextend_threshold and thin_pool_autoextend_percent lines and set each parameter to a required value: 

    thin_pool_autoextend_threshold = 70
thin_pool_autoextend_percent = 20

    thin_pool_autoextend_threshold determines the percentage at which LVM starts to auto-extend the thin pool. For example, setting it to 70 means LVM will try to extend the thin pool when it reaches 70% capacity.

    thin_pool_autoextend_percent specifies by what percentage the thin pool should be extended when it reaches threshold. For example, setting it to 20 means the thin pool will be increased by 20% of its current size.

  5. Save the changes and exit the editor.

  6. Restart the lvm2-monitor: 

    # systemctl restart lvm2-monitor

Additional resources

  • The lvs(8), lvchange(8), dmeventd(8) man pages

4.3.4. Extending a VDO Pool

It is crucial to monitor and periodically extend the capacity of the VDO pool to prevent running out of space.

Logical Volume Manager (LVM) provides the option to manually extend the VDO pool capacity as needed. Alternatively, you can enable monitoring and automate the extension of your VDO pool.

4.3.4.1. Manually extending a VDO Pool

Use the lvextend command to extend a VDO pool.

Prerequisites

  • Administrative access.

Procedure

  1. Display the current VDO usage: 

    # lvs -o lv_name,vg_name,lv_size,data_percent VolumeGroupName/VDOPoolName

  LV          VG              LSize Data%
  VDOPoolName VolumeGroupName 5.00g 60.03

    Replace VolumeGroupName with the name of the volume group. Replace the VDOPoolName with the name of the VDO pool.

  2. Extend the VDO Pool: 

    # lvextend --size PhysicalSize VolumeGroupName/VDOPoolName

    Replace PhysicalSize with the new physical size. Replace VolumeGroupName with the name of the volume group. Replace the VDOPoolName with the name of the VDO pool.

Verification

  1. Verify that the VDO pool is extended: 

    # lvs -o lv_name,vg_name,lv_size,data_percent VolumeGroupName/VDOPoolName

  LV          VG              LSize  Data%
  VDOPoolName VolumeGroupName 10.00g 30.02

Additional resources

  • The lvs(8), lvextend(8) man pages

4.3.4.2. Automatically extending a VDO Pool

You can automate the expansion of your Virtual Data Optimizer (VDO) pool by enabling monitoring and setting the vdo_pool_autoextend_threshold and the vdo_pool_autoextend_percent parameters.

Prerequisites

  • Administrative access.

Procedure

  1. Check if the VDO pool is monitored: 

    # lvs -o name,seg_monitor VolumeGroupName/VDOPoolName

  LV                VG              Monitor
  VDOPoolName       VolumeGroupName not monitored

    Replace VolumeGroupName with the name of the volume group. Replace VDOPoolName with the name of the VDO pool.

  2. Enable VDO pool monitoring with the dmeventd daemon: 

    # lvchange --monitor y VolumeGroupName/VDOPoolName

    Replace VolumeGroupName with the name of the volume group. Replace VDOPoolName with the name of the VDO pool.

  3. As the root user, open the /etc/lvm/lvm.conf file in an editor of your choice.

  4. Uncomment the vdo_pool_autoextend_percent and vdo_pool_autoextend_threshold lines and set each parameter to a required value: 

    vdo_pool_autoextend_threshold = 70
vdo_pool_autoextend_percent = 20

    vdo_pool_autoextend_threshold determines the percentage at which LVM starts to auto-extend the VDO pool. For example, setting it to 70 means LVM tries to extend the VDO pool when it reaches 70% capacity.

    vdo_pool_autoextend_percent specifies by what percentage the VDO pool should be extended when it reaches the threshold. For example, setting it to 20 means the VDO pool will be increased by 20% of its current size.

  5. Save the changes and exit the editor.

  6. Restart the lvm2-monitor: 

    # systemctl restart lvm2-monitor

Additional resources

  • The lvs(8), lvchange(8), dmeventd(8) man pages

4.3.5. Shrinking logical volumes

When the size of the LV is reduced, the freed up logical extents are returned to the volume group and then can be used by other LVs.

Warning

Data stored in the reduced area is lost. Always back up the data and resize the file system before proceeding.

Prerequisites

  • Administrative access.

Procedure

  1. List the logical volumes and their volume groups: 

    # lvs -o lv_name,vg_name,lv_size

  LV                   VG              LSize
  LogicalVolumeName    VolumeGroupName 6.49g

  2. Check where the logical volume is mounted: 

    # findmnt -o SOURCE,TARGET /dev/VolumeGroupName/LogicalVolumeName

SOURCE                                           TARGET
/dev/mapper/VolumeGroupName-NewLogicalVolumeName /MountPoint

    Replace /dev/VolumeGroupName/LogicalVolumeName with the path to your logical volume.

  3. Unmount the logical volume: 

    # umount /MountPoint

    Replace /MountPoint with the mounting point for your logical volume.

  4. Check and repair any file system errors: 

    # e2fsck -f /dev/VolumeGroupName/LogicalVolumeName

  5. Resize the LV and the file system: 

    # lvreduce --size TargetSize --resizefs VolumeGroupName/LogicalVolumeName

    Replace TargetSize with the new size of the LV. Replace VolumeGroupName/LogicalVolumeName with the path to your logical volume.

  6. Remount the file system: 

    # mount -o remount /MountPoint

    Replace /MountPoint with the mounting point for your file system.

Verification

  1. Verify the space usage of the file system: 

    # df -hT /MountPoint/

Filesystem                                       Type  Size  Used Avail Use% Mounted on
/dev/mapper/VolumeGroupName-NewLogicalVolumeName ext4  2.9G  139K  2.7G   1% /MountPoint

    Replace /MountPoint with the mounting point for your logical volume.

  2. Verify the size of the LV: 

    # lvs -o lv_name,lv_size

  LV                   LSize
  NewLogicalVolumeName 4.00g

4.4. Renaming logical volumes

You can rename an existing logical volume, including snapshots, using the lvrename command.

Prerequisites

  • Administrative access.

Procedure

  1. List the logical volumes and their volume groups: 

    # lvs -o lv_name,vg_name

  LV                VG
  LogicalVolumeName VolumeGroupName

  2. Rename the logical volume: 

    # lvrename VolumeGroupName/LogicalVolumeName VolumeGroupName/NewLogicalVolumeName

    Replace VolumeGroupName with name of the volume group. Replace LogicalVolumeName with the name of the logical volume. Replace NewLogicalVolumeName with the new logical volume name.

Verification

  • Verify that the logical volume is renamed: 

    # lvs -o lv_name
  LV
  NewLogicalVolumeName

Additional resources

  • lvrename(8) man page on your system

4.5. Removing logical volumes

You can remove an existing logical volume, including snapshots, using the lvremove command.

Prerequisites

  • Administrative access.

Procedure

  1. List the logical volumes and their paths: 

    # lvs -o lv_name,lv_path

  LV                Path
  LogicalVolumeName /dev/VolumeGroupName/LogicalVolumeName

  2. Check where the logical volume is mounted: 

    # findmnt -o SOURCE,TARGET /dev/VolumeGroupName/LogicalVolumeName

SOURCE                                        TARGET
/dev/mapper/VolumeGroupName-LogicalVolumeName /MountPoint

    Replace /dev/VolumeGroupName/LogicalVolumeName with the path to your logical volume.

  3. Unmount the logical volume: 

    # umount /MountPoint

    Replace /MountPoint with the mounting point for your logical volume.

  4. Remove the logical volume: 

    # lvremove VolumeGroupName/LogicalVolumeName

    Replace VolumeGroupName/LogicalVolumeName with the path to your logical volume.

Additional resources

  • lvs(8), lvremove(8) man pages on your system

4.6. Activating logical volumes

You can activate the logical volume with the lvchange command.

Prerequisites

  • Administrative access.

Procedure

  1. List the logical volumes, their volume groups, and their paths: 

    # lvs -o lv_name,vg_name,lv_path

  LV                VG              Path
  LogicalVolumeName VolumeGroupName VolumeGroupName/LogicalVolumeName

  2. Activate the logical volume: 

    # lvchange --activate y VolumeGroupName/LogicalVolumeName

    Replace VolumeGroupName with the name of the volume group. Replace LogicalVolumeName with the name of the logical volume.

    Note

    When activating a thin LV that was created as a snapshot of another LV, you might need to use the --ignoreactivationskip option to activate it.

Verification

  • Verify that the LV is active: 

    # lvdisplay VolumeGroupName/LogicalVolumeName

  ...
  LV Status              available

    Replace VolumeGroupName with the name of the volume group. Replace LogicalVolumeName with the name of the logical volume.

Additional resources

  • The lvs(8) lvchange(8), lvdisplay(8) man pages

4.7. Deactivating logical volumes

By default, when you create a logical volume, it is in an active state. You can deactivate the logical volume with the lvchange command.

Warning

Deactivating a logical volume with active mounts or in use can lead to data inconsistencies and system errors.

Prerequisites

  • Administrative access.

Procedure

  1. List the logical volumes, their volume groups, and their paths: 

    # lvs -o lv_name,vg_name,lv_path

  LV                VG              Path
  LogicalVolumeName VolumeGroupName /dev/VolumeGroupName/LogicalVolumeName

  2. Check where the logical volume is mounted: 

    # findmnt -o SOURCE,TARGET /dev/VolumeGroupName/LogicalVolumeName

SOURCE                                        TARGET
/dev/mapper/VolumeGroupName-LogicalVolumeName /MountPoint

    Replace /dev/VolumeGroupName/LogicalVolumeName with the path to your logical volume.

  3. Unmount the logical volume: 

    # umount /MountPoint

    Replace /MountPoint with the mounting point for your logical volume.

  4. Deactivate the logical volume: 

    # lvchange --activate n VolumeGroupName/LogicalVolumeName

    Replace VolumeGroupName with name of the volume group. Replace LogicalVolumeName with the name of the logical volume.

Verification

  • Verify that the LV is not active: 

    # lvdisplay VolumeGroupName/LogicalVolumeName

  ...
  LV Status              NOT available

    Replace VolumeGroupName with name of the volume group. Replace LogicalVolumeName with the name of the logical volume.

Additional resources

  • The lvs(8) lvchange(8), lvdisplay(8) man pages
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