Open System Services NFS Management and Operations Guide

Effect
Attempted operation fails.
Recovery
If the specified device does not exist, correct the device name (specify a device that does exist)
and retry the operation.
If the attempted operation is illegal on the device, corrective action is application-dependent.
Either the type of operation must be changed or the operation must be retried on a device on
which the operation is valid.
NFS2 Error 20
Not a directory. The caller specified a nondirectory in a directory
operation.
Cause
The caller attempted a directory operation but did not specify a directory. Generally, the error
is caused by an incorrectly specified pathname (for example, a filename appeared in a pathname
where only a directory name is allowed).
Effect
Attempted operation fails.
Recovery
If the operation was correct but a filename was specified rather than a directory name, correct
the pathname so that a directory is specified. Otherwise, a caller logic error is indicated and
must be corrected.
NFS2 Error 21
Is a directory. The caller specified a directory in a nondirectory
operation.
Cause
The caller attempted to perform an operation on a directory that is not allowed on a directory
(such as a write). Generally, the problem is an attempt to perform an operation on an incorrectly
specified file.
Effect
Attempted operation fails.
Recovery
If the operation was correct but a directory was specified rather than a file, correct the pathname
so that a file is specified. Otherwise, a caller logic error is indicated and must be corrected.
NFS2 Error 22
Invalid argument. The caller specified an argument that was invalid for
the specified operation.
Cause
The caller attempted to perform a READLINK operation on a file that is not a symbolic link file.
Effect
Attempted operation fails.
Recovery
If the operation was correct but an incorrect filename was specified, correct the pathname so
that the correct file is specified. Otherwise, a caller logic error is indicated and must be corrected.
NFS2 Error 27
File too large. The operation attempted would cause the size of the
affected file to exceed the maximum file size.
88 NFS Protocol Version 2 Errors and Mount Protocol Version 1 Errors