NFS Linux Server RPCs Test

NFS relies on Remote Procedure Calls (RPC) between clients and servers. Bad RPC or failure/corruption of RPC calls may result in clients being unable to access the shared file systems. Using this test, administrators can closely monitor the RPC calls and promptly identify snags in client-server communication.

Target of the test : NFS on Linux Server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every remotely mounted NFS.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed
Host	The host for which the test is to be configured.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Number of RPC calls	Indicates the total number of RPC calls received from clients to the NFS server during the last measurement period.	Number	This is a good indicator of the workload on the server.
Number of corrupted RPC requests	Indicates the total number of number of RPC calls with a length shorter than a minimum-sized RPC call during the last measure period.	Number	Ideally, the value of these measures should be 0. A non-zero value for these measures could indicate malformed NFS requests that can be caused by bugs in the client or server software or by physical network problems.
Percentage of corrupted RPC requests	Indicates the percentage of truncated or damaged packets during the last measurement period.	Percent
Number of RPC call failures	Indicates the total number of calls rejected by the RPC layer in the NFS server during the last measurement period.	Number	Ideally, the value of these measures should be 0.
Percentage of RPC call failures	Indicates the percentage of calls rejected by the RPC layer in the NFS during the last measurement period.	Percent	Ideally, the value of these measures should be 0.
Number of bad authentication requests	Indicates the total number of bad authentication requests received from clients to the NFS server during the last measure period.	Number	The only time NFS performs authentication is when a client system attempts to mount the shared NFS resource. To limit access to the NFS service, TCP wrappers are used. TCP wrappers read the /etc/hosts.allow and /etc/hosts.deny files to determine if a particular client or network is permitted or denied access to the NFS service. Authentication errors can occur from bad /etc/hosts.allow entries. A high value for these measures is a cause for concern.
Percentage of bad authentication requests	Indicates the percentage of bad authentication requests during the last measurement period.	Percent
Number of corrupted data headers	Indicates the number of RPC calls whose header could not be XDR decoded during the last measurement period.	Number	XDR is a standard for the description and encoding of data. It is useful for transferring data between different computer architectures, and it has been used to communicate data between diverse machines. All data in an RPC message is XDR encoded. The encoding of XDR data into transport buffers is referred to as "marshalling", and the decoding of XDR data contained within transport buffers and into destination RPC procedure result buffers, is referred to as "unmarshalling". Therefore, the process of marshalling takes place at the sender of any particular message, be it an RPC request or an RPC response. Unmarshalling, of course, takes place at the receiver. If 'unmarshalling' of an RPC request/response fails, it implies that the XDR decode has failed. Ideally, the value of this measure should be 0. A high value indicates too many malformed NFS requests, which can be caused by bugs in the client or server software or by physical network problems.
Percentage of corrupted data headers	Indicates the percentage of corrupted data headers during the last measurement period.	Percent