Red Hat GLOBAL FILE SYSTEM 5.0, Руководство администратора

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vgscan
command, see Section 3.4, “Scanning Disks for Volume Groups to Build the Cache
File” .
The
vgs
command provides volume group information in a configurable form, displaying one
line per volume group. The
vgs
command provides a great deal of format control, and is useful
for scripting. For information on using the
vgs
command to customize your output, see
Section 9, “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
3.4. 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
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. You may need to run the
vgscan
command manually when you change your
hardware configuration, 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 6, “Controlling
Chapter 4. LVM Administration with CLI Commands
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