Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Managing Disks and Files
Managing Disks
Chapter 6596
your volume group will still remain active; however, a message will be
printed to the console indicating that the volume group has lost quorum.
Until the quorum is restored (at least one of the LVM disks in the volume
group in the above example is once again available), LVM will not allow
you to complete most commands that affect the volume group
configuration. Further, some of the I/O accesses to the logical volumes for
that volume group may hang because the underlying disks are not
accessible. Also, until quorum is restored, the Mirror Write Cache
(MWC) will not be updated because LVM cannot guarantee the
consistency (integrity) of the LVM information.
Even when allowed by LVM, it is recommended that you do not make
changes to the LVM configuration for active volume groups that do not
have a quorum of disks present.
There are ways to override quorum requirements at volume group
activation time, or at boot time. These will be discussed in the following
two sections. However, the recommended way to correct this problem is
to return the unavailable disks to service.
Quorum Problems
with a Non-Root
Volume Group
If you attempt to activate a nonroot volume group when not enough disks
are present to establish a quorum, you will see error messages similar to
the following:
vgchange -a y /dev/vg01
vgchange: Warning: Couldn't attach to the volume group
physical volume "/dev/dsk/c1t0d2":
The path of the physical volume refers to a device that does not exist, or is not
configured into the kernel.
vgchange: Couldn't activate volume group "/dev/vg01":
Either no physical volumes are attached or no valid VGDAs were found on the
physical volumes.
If a nonroot volume group does not get activated because of a failure to
meet quorum, try the following:
1. Check the power and data connections of all the disks that are part of
the volume group that you cannot activate. Return all disks (or, at
least enough to make a quorum) to service. Then, use the vgchange
command to try to activate the volume group again.
2. If there is no other way to make a quorum available, the -q option of
the vgchange command will override the quorum requirement.
vgchange -a y -q n /dev/vg01