HP-UX Reference (11i v2 03/08) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)

m
maxvgs(5) maxvgs(5)
(Tunable Kernel Parameters)
NAME
maxvgs - maximum number of LVM Volume Groups that can be created/activated on the system
VALUES
Failsafe
10
Default
10
Allowed values
1-256
Recommended values
10-256
The value for maxvgs should be no larger than the anticipated needs of the system. Resources are
reserved for the number of volume groups indicated, so setting an unnecessarily large
maxvgs value on
systems with limited resources is not advisable. Conversely, it does not make sense to set
maxvgs to a
low value since it will likely have to be raised later when a greater number of volume groups is utilized.
DESCRIPTION
Maximum number of LVM Volume Groups which may be created or activated on the system. This value
also limits the range of Volume Group numbers allowed. A
maxvgs
value of 10, for example, allows 10
Volume Groups to be created on the system, and the Volume Group number of each Volume Group is a
unique value in the range of 0 to 9.
Who Is Expected to Change This Tunable?
Anyone.
Restrictions on Changing
When
maxvgs is modified the change takes effect at the next system reboot.
When Should the Value of This Tunable Be Raised?
A Volume Group cannot be created or activated if its volume group number exceeds
maxvgs. If this
occurs, the customer should choose a volume group number that does not exceed
maxvgs, or raise the
maxvgs value to accommodate the volume group number chosen.
What Are the Side Effects of Raising the Value of This Tunable?
Additional kernel resources are consumed. Approximately 4-8KB of lockable physical memory is con-
sumed by advancing the
maxvgs value by 1.
When Should the Value of This Tunable Be Lowered?
On systems with very limited kernel memory, lowering
maxvgs to 10 or less may free memory for other
uses. Lower the maxvgs value only when it is certain that the number of Volume Groups to be created or
activated on the system will not exceed the new value.
What Are the Side Effects of Lowering the Value of This Tunable?
If
maxvgs is set to too small a value, it is possible that some volume groups cannot be created or
activated.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its
meaning changed in future releases of HP-UX.
AUTHOR
maxvgs was developed by HP.
SEE ALSO
lvm(7).
HP-UX 11i Version 2: August 2003 − 1 − Hewlett-Packard Company Section 5−−171