Hitachi Dynamic Link Manager Software Users Guide for AIX (6.6) (T5208-96010, April 2011)

3. Creating an HDLM Environment
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3.9 About the Reservation Policy
The reservation policy settings are explained in the following table.
Table 3-21: Reservation Policy Settings
About changing the reservation policy
• You should check that the hdisk is not being accessed by any other programs
before you attempt to change the reservation policy.
• When you change the reservation policy, the I/O count and error count are
cleared.
• The status of the paths is changed to
Online.
• Make sure that there are no path errors before you change the reservation
policy.
If the reservation policy is changed while there is an error in a path, the
erroneous path is deleted.
To recover from this status, resolve the error and then execute one of the
following commands:
mkdev -l hdisk-name
cfgmgr
Setting Description
no_reserve Ignores a reservation request and does not reserve an LU. This setting is used when any
of the following are applicable:
• Multiple hosts share an LU and execute unique applications that have an exclusive
control feature
• A virtual I/O function is used to set up an MPIO configuration for a virtual SCSI disk
in a client partition
• A virtual I/O function is applied in order to use HACMP in a client partition
• In an Oracle RAC environment, the hdisk for an HDLM-managed device is specified
as a disk used by Oracle RAC
PR_exclusive Replaces a reservation with a persistent reservation.