Installation guide

Chapter 4. LVM Administration with CLI Commands
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For information on using the vgs command to customize your output, see Section 4.8, “Customized
Reporting for LVM”.
The vgdisplay command displays volume group properties (such as size, extents, number of
physical volumes, etc.) in a fixed form. The following example shows the output of a vgdisplay
command for the volume group new_vg. If you do not specify a volume group, all existing volume
groups are displayed.
# vgdisplay new_vg
--- Volume group ---
VG Name new_vg
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 11
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 0
Max PV 0
Cur PV 3
Act PV 3
VG Size 51.42 GB
PE Size 4.00 MB
Total PE 13164
Alloc PE / Size 13 / 52.00 MB
Free PE / Size 13151 / 51.37 GB
VG UUID jxQJ0a-ZKk0-OpMO-0118-nlwO-wwqd-fD5D32
4.3.5. Scanning Disks for Volume Groups to Build the Cache File
The vgscan command scans all supported disk devices in the system looking for LVM physical
volumes and volume groups. This builds the LVM cache in the /etc/lvm/cache/.cache file, which
maintains a listing of current LVM devices.
LVM runs the vgscan command automatically at system startup and at other times during LVM
operation, such as when you execute a vgcreate command or when LVM detects an inconsistency.
Note
You may need to run the vgscan command manually when you change your hardware
configuration and add or delete a device from a node, causing new devices to be visible to the
system that were not present at system bootup. This may be necessary, for example, when you
add new disks to the system on a SAN or hotplug a new disk that has been labeled as a physical
volume.
You can define a filter in the lvm.conf file to restrict the scan to avoid specific devices. For
information on using filters to control which devices are scanned, see Section 4.5, “Controlling LVM
Device Scans with Filters”.
The following example shows the output of a vgscan command.