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

3. Creating an HDLM Environment
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# /usr/DynamicLinkManager/bin/dlnkmgr view -sys
 When you use HACMP, GPFS, Oracle RAC 10g, Oracle RAC 11g, or VCS,
settings such as script registration or the reservation policy setting are required.
For details about the settings used for each cluster, see the following:
For HACMP: 3.10 Settings for Using HACMP.
For GPFS: 3.11 Settings for Using GPFS.
For Oracle RAC 10g or Oracle RAC 11g: 3.12 Settings for Using Oracle RAC
10g or Oracle RAC 11g.
For VCS: 3.13 Settings for Using VCS.
 If you are using HACMP, note that HDLM does not support non-concurrent
volume groups due to limitations in HACMP. For details, contact IBM.
 If all of the following conditions are met, HDLM can be migrated without
stopping HACMP services:
• The shared volume groups used by HACMP are concurrent volume groups.
• A custom disk method is specified in the HACMP script.
• A virtual I/O server environment is not used on the host.
3.4.8 Notes on the Automatic Failback
If the automatic failback processing starts before a path failure has been recovered
from, the cluster system switchover time might become longer. To prevent this, for the
automatic failback checking interval, specify a value that is greater than the value
obtained from the following formula:
checking-interval (minutes)
= maximum-number-of-paths-among-the-LUs
x
number-of-connected-storage-devices
3.4.9 Notes on the queue_depth Parameter Value for an
HDLM-Managed device
Hitachi recommends that you set the queue_depth parameter of an hdisk for an
HDLM-managed device to a value greater than or equal to the number of paths that are
connected to the hdisk. For details on how to specify the
queue_depth parameter, see
the AIX documentation.