maxvgs(5)                                                         maxvgs(5)
                          Tunable Kernel Parameters



 NAME    [Toc]    [Back]
      maxvgs - maximum number of LVM Volume Groups that can be
      created/activated on the system

 VALUES    [Toc]    [Back]
    Failsafe
      10

    Default    [Toc]    [Back]
      10

    Allowed values    [Toc]    [Back]
      1-256

    Recommended values    [Toc]    [Back]
      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    [Toc]    [Back]
      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    [Toc]    [Back]
      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 consumed 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



 Hewlett-Packard Company            - 1 -      HP-UX 11i Version 2: Sep 2004






 maxvgs(5)                                                         maxvgs(5)
                          Tunable Kernel Parameters



      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    [Toc]    [Back]
      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.

      Installation of optional kernel software, from HP or other vendors,
      may cause changes to tunable parameter values.  After installation,
      some tunable parameters may no longer be at the default or recommended
      values.  For information about the effects of installation on tunable
      values, consult the documentation for the kernel software being
      installed. For information about optional kernel software that was
      factory installed on your system, see HP-UX Release Notes at
      http://docs.hp.com.

 AUTHOR    [Toc]    [Back]
      maxvgs was developed by HP.

 SEE ALSO    [Toc]    [Back]
      lvm(7).


 Hewlett-Packard Company            - 2 -      HP-UX 11i Version 2: Sep 2004