Hitachi Dynamic Link Manager Software Users Guide for AIX

Note
Depending on the HBA, you need to repeat steps b and c.
For details on the position of slots, see the manual of the host.
CHA port number
The port number of the CHA.
You can check this number by using the dlnkmgr command's view
operation. For details on the view operation, see
view (Displays
Information) on page 6-34.
AutoPATH_ID
The ID assigned to a path. This ID is re-assigned each time the host or
the HDLM Manager is started.
You can check this ID by using the dlnkmgr command's view operation.
For details on the view operation, see view (Displays Information) on
page 6-34.
Automatic failbacks
When a path recovers from an error, HDLM can automatically place the
recovered path back online. This function is called the automatic failback
function.
In order to use the automatic failback function, HDLM must already be
monitoring error recovery on a regular basis.
When using the Thunder 9500V series, or Hitachi AMS/WMS series HDLM will
select the next path to be used first from among the online owner paths, and
then from the online non-owner paths. As a result, if an owner path recovers
from an error, and then HDLM automatically places the recovered path online
while a non-owner path is in use, the path will be automatically switched over
from the non-owner path to the owner path that just recovered from the
error.
When the Lightning 9900V series, Hitachi USP series, Universal Storage
Platform V/VM series, Virtual Storage Platform series, VSP G1000 series,
Hitachi AMS2000 series
#1
, Hitachi SMS series
#1
, HUS100 series
#1
, or HUS
VM is being used, all the paths are owner paths. Therefore, if an owner path
recovers from an error and HDLM automatically places the recovered path
online, the path to use is not switched.
When intermittent errors
#2
occur on paths and you are using the automatic
failback function, the path status might frequently alternate between the
online and offline statuses. In such a case, because the performance of I/Os
will most likely decrease, if there are particular paths in which intermittent
errors might be occurring, we recommend that you set up intermittent error
monitoring so you can detect these paths, and then remove them from those
subject to automatic failbacks.
You can specify the automatic failback function or intermittent error by the
dlnkmgr command's set operation. For details on the set operation, see
set
(Sets Up the Operating Environment) on page 6-18.
2-18
HDLM Functions
Hitachi Dynamic Link Manager (for AIX) User Guide