HP XP P9500 Storage - Manual (Page 298)

Notes on Using HDLM
Note the following when using HDLM.
Notes Common to OSs
The following notes are common to OSs:
• Do not activate the same volume group concurrently from multiple
servers.
• When a path error exists, the period of time required to return a response
to the application that made an I/O request to HDLM depends on the
timeout values specified for the fibre channel switch and HBA.
Therefore, if an error occurs in all the paths for a single LU, this response
time will be the total period of time required for the corresponding fibre
channel switches and HBAs to detect a timeout for the I/O requested for
each path.
For details on the timeout values for fibre channel switches and HBAs, see
the appropriate manual for the device. Figure 4-1 Overview of the Period
Required to Respond to an Application's I/O Request on page 4-3 gives
an overview of the period required to return a response: from the time an
application requests an I/O, to the time the application receives the
response.
4-2
HDLM Operation
Hitachi Dynamic Link Manager User Guide (for Linux(R))