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man pages section 8: System Administration Commands

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Updated: Wednesday, July 27, 2022
 
 

nfsstat(8)

Name

nfsstat - NFS statistics

Synopsis

nfsstat [-cnrsza] [-T u | d ] [-v version] [interval [count]]
nfsstat -m [pathname]...

Description

nfsstat displays statistical information about the NFS and RPC (Remote Procedure Call), interfaces to the kernel. It can also be used to reinitialize this information. If no options are given the default is as follows:

nfsstat –csnra

The default displays everything, but reinitializes nothing.

Options

–a

Display NFS_ACL information.

–c

Display client information. Only the client-side NFS, RPC, and NFS_ACL information is printed. Can be combined with the –n, –r, and –a options to print client-side NFS, RPC, and NFS_ACL information only.

–m [pathname...]

Display statistics for each NFS mounted file system. If pathname is not specified, displays statistics for all NFS mounted file systems. If pathname is specified, displays statistics for the NFS mounted file systems indicated by pathname.

This includes the server name and address, mount flags, current read and write sizes, the retransmission count, the attribute cache timeout values, failover information, and the timers used for dynamic retransmission. The dynamic retransmission timers are displayed only where dynamic retransmission is in use. By default, NFS mounts over the TCP protocols and NFS Version 3 mounts over either TCP or UDP do not use dynamic retransmission.

If you specify the –m option, this is the only option that nfsstat uses. If you specify other options with –m, you receive an error message alerting that the –m flag cannot be combined with other options.

–n

Display NFS information. NFS information for both the client and server side are printed. Can be combined with the –c and –s options to print client or server NFS information only.

–r

Display RPC information.

–s

Display server information.

–T u | d

Display a time stamp.

Specify u for a printed representation of the internal representation of time. See time(2). Specify d for standard date format. See date(1).

–v version

Specify which NFS version for which to print statistics. When followed by the optional version argument, (2, 3, 4, 4.0, 4.1), specifies statistics for that version. By default, prints statistics for all versions. '-v 4' will print statistics for both 4.0 and 4.1.

–z

Zero (reinitialize) statistics. This option is for use by the super user only, and can be combined with any of the above options to zero particular sets of statistics after printing them.

Operands

The following operands are supported:

count

Display only count reports

interval

Report once each interval seconds.

pathname

Specify the pathname of a file in an NFS mounted file system for which statistics are to be displayed.

DISPLAYS

The server RPC display includes the following fields:

badcalls

The total number of calls rejected by the RPC layer (the sum of badlen and xdrcall as defined below).

badlen

The number of RPC calls with a length shorter than a minimum-sized RPC call.

calls

The total number of RPC calls received.

dupchecks

The number of RPC calls that looked up in the duplicate request cache.

dupreqs

The number of RPC calls that were found to be duplicates.

nullrecv

The number of times an RPC call was not available when it was thought to be received.

xdrcall

The number of RPC calls whose header could not be XDR decoded.

The server NFS display shows the number of NFS calls received (calls) and rejected (badcalls), and the counts and percentages for the various calls that were made.

The server NFS_ACL display shows the counts and percentages for the various calls that were made.

The client RPC display includes the following fields:

calls

The total number of RPC calls made.

badcalls

The total number of calls rejected by the RPC layer.

badverfs

The number of times the call failed due to a bad verifier in the response.

badxids

The number of times a reply from a server was received which did not correspond to any outstanding call.

cantconn

The number of times the call failed due to a failure to make a connection to the server.

cantsend

The number of times a client was unable to send an RPC request over a connectionless transport when it tried to do so.

interrupts

The number of times the call was interrupted by a signal before completing.

newcreds

The number of times authentication information had to be refreshed.

nomem

The number of times the call failed due to a failure to allocate memory.

retrans

The number of times a call had to be retransmitted due to a timeout while waiting for a reply from the server. Applicable only to RPC over connection-less transports.

timeouts

The number of times a call timed out while waiting for a reply from the server.

timers

The number of times the calculated time-out value was greater than or equal to the minimum specified time-out value for a call.

The client NFS display shows the number of calls sent and rejected, as well as the number of times a CLIENT handle was received (clgets), the number of times the CLIENT handle cache had no unused entries (cltoomany), as well as a count of the various calls and their respective percentages.

The client NFS_ACL display shows the counts and percentages for the various calls that were made.

The –m option includes information about mount flags set by mount options, mount flags internal to the system, and other mount information. See mount_nfs(8).

The following mount flags are set by mount options:

forcedirectio

Data transferred directly between client and server, with no buffering on client.

grpid

BSD group id inheritance. See description in mount_nfs(8).

hard

Hard mount.

intr

Interrupts allowed on hard mount.

llock

Local locking being used (no lock manager). Note that this is a private interface.

noac

Client is not caching attributes.

nointr

No interrupts allowed on hard mount.

nocto

No close-to-open consistency.

retrans

NFS retransmissions.

rpctimesync

RPC time sync.

rsize

Read buffer size in bytes.

sec

sec has one of the following values:

dh

des–style authentication (encrypted timestamps).

krb5

kerberos v5–style authentication.

krb5i

kerberos v5–style authentication with integrity.

krb5p

kerberos v5–style authentication with privacy.

none

No authentication.

short

Short hand UNIX–style authentication.

sys

UNIX-style authentication (UID, GID).

soft

Soft mount.

timeo

Initial NFS timeout, in tenths of a second.

wsize

Write buffer size in bytes.

The following mount flags are internal to the system:

acl

Server supports NFS_ACL and noacl mount flag was not set by mount options.

down

Server is down.

dynamic

Dynamic transfer size adjustment.

link

Server supports links.

mirrormount

Mounted automatically by means of the mirrormount mechanism.

printed

“Not responding” message printed.

readdironly

Use readdir instead of readdirplus.

referral

Mounted automatically by means of the referral mechanism.

symlink

Server supports symbolic links.

xattr

Server supports extended attributes over NFS_ACL.

The following flags relate to additional mount information:

proto

Transport protocol.

vers

NFS version.

mvers

NFSv4 minor version.

The –m option also provides attribute cache timeout values. The following fields in –m output provide timeout values for attribute cache:

acdirmax

Maximum seconds to hold cached directory attributes.

acdirmin

Minimum seconds to hold cached directory attributes.

acregmax

Maximum seconds to hold cached file attributes.

acregmin

Minimum seconds to hold cached file attributes.

The following fields in –m output provide failover information:

currserver

Which server is currently providing NFS service.

failover

How many times a new server has been selected.

noresponse

How many times servers have failed to respond.

remap

How many times files have been re-evaluated to the new server.

The following fields in –m output provide RDMA transport information:

plugin

The transport plugin being used.

The fields in –m output shown below provide information on dynamic retransmissions. These items are displayed only where dynamic retransmission is in use.

cur

Current backed-off retransmission value, in milliseconds.

dev

Estimated deviation, in milliseconds.

srtt

The value for the smoothed round-trip time, in milliseconds.

Exit Status

The following exit values are returned:

0

Successful completion.

>0

An error occurred.

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Availability
system/file-system/nfs

See Also

attributes(7), mount_nfs(8)