HP Tru64 UNIX and TruCluster Server Version 5.1B-5 Patch Summary and Release Notes (March 2009)

Once you have started SysMan, you will need to modify the configuration of each IPsec
and IKE connection to add the identity of the remote hosts that are allowed to connect.
You enter this information on the third dialog box you see during the connection
configuration wizard; the dialog box is titled “Manage IPsec: Add/Modify Connection:
IKE Proposal.” Although you can leave the “Restrict To The Following Remote IDs”
list empty, doing so will mean that any identity given to the local machine by the remote
hosts will be considered valid as long as they send the correct certificate or preshared
key.
3.2.2.19 Potential NFS Duplicate Request Cache Scalability Limitation with High Loads and
Uncharacteristic File Access Behavior on Clustered NFS Servers
Repeated simultaneous overwriting of many files can cause retransmitted writes to be
processed after recent writes of a file to the same location. This problem occurs more
often on systems configured with a LAN cluster interconnect than on those configured
with Memory Channel.
This behavior is inherent in the "stateless" design of NFS. Although the behavior has
been mitigated via a "duplicate request cache" that replays old replies instead of
reexecuting retransmitted requests, extremely heavy loads on large systems can
overwhelm the cache when requests are stalled. Customers are unlikely to see problems
because applications rarely rewrite files almost immediately.
If the problem occurs, the NFS server displays the following message several times a
minute on the system console, indicating that the NFS server is being overwhelmed
with requests :
"NFS server xxx not responding"
When an "overwhelmed duplicate request cache" condition has occurred, the NFS client
will display multiple occurrences of either of the following messages:
NFS3 server xxx not responding still trying
NFS3 server xxx ok
NFS2 server xxx not responding still trying
NFS2 server xxx ok
This indicates that the client is observing transient unresponsive periods at the server.
This is the only notification that the client will display if the server's duplicate request
cache becomes overwhelmed. When the client detects this behavior, it increases the
retransmission interval until it gets a response from the server. This behavior is generally
indistinguishable from the server going up and down, except that the messages are
displayed with such frequency that the server system/member cannot have gone down
and then come back up in that short an interval.
You can minimize the likelihood of these problems as follows:
70 Tru64 UNIX Patches