5.
Note that the number of extents for
/dev/disk/disk47
is increased from 25604 to 38396
after the maximum VG size is increased, as shown by
vgdisplay -v
here. This command
confirms that the maximum VG size was increased from 500 GB to 8 TB, and that the number
of extents for
/dev/disk/disk47
was increased from 25602 extents to 38396 extents, as
shown by the
vgdisplay
command below.
# vgdisplay –v vg1
--- Volume groups ---
VG Name /dev/vg1
...
PE Size (Mbytes) 8
Total PE 76792
Alloc PE 51196
Free PE 25596
...
VG Version 2.1
VG Max Size 8t
VG Max Extents 1048576
--- Logical volumes ---
LV Name /dev/vg1/lvol1
LV Status available/syncd
LV Size (Mbytes) 204784
Current LE 25598
Allocated PE 51196
Used PV 2
--- Physical volumes ---
PV Name /dev/disk/disk46
PV Status available
Total PE 38396
Free PE 12798
...
PV Name /dev/disk/disk47
PV Status available
Total PE 38396
Free PE 12798
Quiescing and Resuming a Volume Group
If you plan to use a disk management utility to create a backup image or “snapshot” of all the
disks in a volume group, you must make sure that LVM is not writing to any of the disks when the
snapshot is being taken; otherwise, some disks can contain partially written or inconsistent LVM
metadata. To keep the volume group disk image in a consistent state, you must either deactivate
the volume group or quiesce it.
Deactivating the volume group requires you to close all the logical volumes in the volume group,
which can be disruptive. For example, you must unmount any file system using a logical volume
in the volume group. However, temporarily quiescing the volume group enables you to keep the
volume group activated and the logical volumes open during the snapshot operation, minimizing
the impact to your system.
You can quiesce both read and write operations to the volume group, or just write operations.
While a volume group is quiesced, the
vgdisplay
command reports the volume group access
mode as
quiesced
. The indicated I/O operations queue until the volume group is resumed, and
commands that modify the volume group configuration fail immediately.
Common LVM Tasks
65