Hitachi Dynamic Link Manager Software Users Guide for AIX

Table Of Contents
2. When GPFS or GPFS+RVSD is used, in the dlmodmset utility for setting
the HDLM execution environment ODM, set the LUN RESET option to on.
# /usr/DynamicLinkManager/bin/dlmodmset -r on
Settings for Using Oracle RAC 10g or Oracle RAC 11g
Settings for MISSCOUNT and DISKTIMEOUT
When a host and an Oracle RAC voting disk are connected by multiple paths,
HDLM performs failover processing for those paths (in the same way as for
normal paths) when an I/O timeout occurs for one of the paths.
Note that, depending on the settings of Oracle RAC, Oracle RAC might
determine that a node error has occurred before the failover processing
performed by HDLM is completed, and then re-configure the cluster.
Therefore, when HDLM manages the paths that are connected to an Oracle
RAC voting disk, change the following settings according to your version of
Oracle RAC:
When using Oracle RAC 10g 10.1.0.3.0 or later or Oracle RAC 11g:
Change the value of MISSCOUNT to match the type of storage system. To
do so, use the following table to obtain the value to be specified, and then
change the current value to a value equal to or greater than the value
you have obtained.
Table 3-22 Formula for Calculating MISSCOUNT
Storage system type Formula for obtaining the value of MISSCOUNT
Hitachi
AMS2000/AMS/WMS/SMS
series
HUS100 series
Thunder 9500V series
number-of-paths-connected-to-the-voting-disk × 30
seconds
Hitachi USP series
Lightning 9900V series
Universal Storage Platform
V/VM series
Virtual Storage Platform
series
VSP G1000 series
HUS VM
number-of-paths-connected-to-the-voting-disk × 60
seconds
When using Oracle RAC 10g 10.2.0.2.0 or later or Oracle RAC 11g:
In addition to the value of MISSCOUNT shown above, also change the value
of DISKTIMEOUT. As with MISSCOUNT, the value to be specified in
DISKTIMEOUT is determined by the type of storage system. To make the
change, use the following table to obtain the value to be specified, and
3-98
Creating an HDLM Environment
Hitachi Dynamic Link Manager (for AIX) User Guide