HP-UX Reference (11i v3 07/02) - 1M System Administration Commands N-Z (vol 4)

vgchange(1M) vgchange(1M)

vgchange -Q rw -t 600 /dev/vg03

WARNINGS

Ordinary Operation

In ordinary operation (that is, without the optional high availability software), it is possible to activate a

volume group for read-write access from more than one physically connected system, leading to a high

potential for data corruption. Therefore, if access is desired from more than one system to a single volume

group, it is important that only one system activate the volume group for read-write access; the other sys-

tems can use read-only access. There is no problem if all systems activate the volume group for read-only

access.

Furthermore, volume group information is only read from the disks during volume group activation.

Dynamic changes to the volume group such as the following are not propagated to other systems sharing

the volume group:

Logical volume conﬁguration changes.

Changes to the status of the mirrored extents.

Bad-block relocation that occurs during write operations.

Because of these limitations, when sharing volume groups between systems it is recommended that logical

volumes be accessed only by one system at a time. If logical volumes must be accessed simultaneously, the

logical volumes should not be mirrored and should not have bad-block relocation turned on, or all systems

should use read-only access to the logical volumes.