Managing NFS and KRPC Kernel Configurations in HP-UX 11i v2 (November 2013)

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2.4.2 rpc_svc_cotsmaxdupreqs
Description
The rpc_svc_cotsmaxdupreqs tunable controls the size of the duplicate request cache that detects RPC
level transmissions on connection-oriented transports such as TCP. This cache avoids processing of
retransmitted requests that might be non-idempotent.
Tested values
Default: 1024
Min: 1
Max: 2048
Note: If the tunable is set to a value greater than 2048, an
informational warning is issued at runtime. This value is
outside the tested limits.
Restrictions on changing
The rpc_svc_cotsmaxdupreqs tunable is dynamic. System reboot is not required to activate a change
made to this tunable. However, if the cache is full, decreasing the current value has no effect unless
the system is rebooted.
Modifying the value
Increasing the value of this tunable higher than the default can result in longer search times to find
entries in the cache. This can affect the performance of the NFS server. If a non-idempotent request is
mistakenly serviced twice by the NFS server, decreasing the value of this tunable can trigger false
failures on the NFS client side. For example, if an attempt to create a directory returns a status of
failed but the directory is actually created, the retransmitted MKDIR request was not detected by the
server. HP recommends leaving the rpc_svc_cotsmaxdupreqs tunable set to the default value unless
you have been explicitly instructed to change it by HP Support.
2.4.3 rpc_svc_idle_timeout
Description
The rpc_svc_idle_timeout tunable controls the time interval, in milliseconds, that a TCP connection
between the server and client may remain idle before it is forcibly closed by the NFS server system.
Tested values
Default: 360000 (6 minutes)
Min: 1000 (1 second)
Max: 600000 (10 minutes)