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

3. Creating an HDLM Environment
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3.12 Settings for Using Oracle RAC 10g or Oracle RAC 11g
3.12.1 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 3-24: Formula for Calculating MISSCOUNT
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 then change the current
value to a value equal to or greater than the value you have obtained.
Storage system type Formula for obtaining the value of MISSCOUNT
• Hitachi AMS2000/AMS/WMS/SMS
series
• Thunder 9500V series
number-of-paths-connected-to-the-voting-disk
x 30 seconds
• Hitachi USP
• Lightning 9900V series
• Universal Storage Platform V/VM
• Virtual Storage Platform
number-of-paths-connected-to-the-voting-disk x 60 seconds