HP-UX Reference (11i v2 03/08) - 1M System Administration Commands N-Z (vol 4)

r
rexd(1M) rexd(1M)
DIAGNOSTICS
The following is a subset of the messages that could appear in the log file if the
-l option is used. Some
of these messages are also returned to the client.
rexd: could not umount: dir
rexd was unable to umount() the user’s current working file system. See WARN-
INGS for more details.
rexd: mountdir (mountdir) is not a directory
The path name mountdir, under which temporary mount points are created, is not a
directory or does not exist.
rexd: command: Command not found
rexd could not find command.
rexd: command: Permission denied
rexd was denied permission to execute command.
rexd: command: Text file busy
The executable file is currently open for writing.
rexd: command: Can’t execute
rexd was unable to execute command.
rexd: root execution not allowed
rexd does not allow execution as user root.
rexd: User id uid not valid
The uid uid is not assigned to a user on the server.
rexd: User id uid denied access
rexd was started with the -r option and the remote execution request did not meet
either of the conditions required by the -r option.
rexd: host is not running a mount daemon
The host host on which the user’s current working directory is located is not running
mountd. Therefore, rexd is unable to mount the required file system (see
mountd(1M)).
rexd: not in export list for file_system
The host on which the client’s current working directory is located does not have the
server on the export list for file system file_system containing the client’s current work-
ing directory. Therefore, rexd is unable to mount the required file system.
WARNINGS
The client’s environment is simulated by
rexd, but not completely recreated. The simulation of the
client’s environment consists of mounting the file system containing the client’s current working directory
(if it is not already mounted) and setting the user’s environment variables on the server to be the same as
the user’s environment variables on the client. Therefore a command run by rexd does not always have
the same effect as a command run locally on the client.
The
rex protocol only identifies the client user by sending the uid of the client process and the host name
of the client. Therefore, it is very difficult for rexd to perform user authentication. If a user on the
server is assigned to the uid sent by the client, rexd executes the requested command as that user. If no
user on the client is assigned to the uid sent by the client, rexd returns an error.
The
-r option has been added to provide increased user authentication. However, the authentication
provided is not foolproof, and is limited by the information passed by the rex protocol.
In order to simulate the client’s environment,
rexd mounts the file system containing the client’s current
working directory (if it is not already mounted). This mount is intended to be temporary for the duration
of the command.
If
rexd mounts a file system, it attempts to umount() the file system after the command has completed
executing. However, if rexd receives a SIGKILL signal (see signal(2)), the file system is not
unmounted. The file system remains mounted until the superuser executes the appropriate umount
command or the server is rebooted.
rexd’s attempt to umount the file system can also fail if the file system is busy. The file system is busy if
it contains an open file or a user’s current working directory. The file system remains mounted until the
superuser executes the appropriate umount command or the server is rebooted.
HP-UX 11i Version 2: August 2003 − 2 − Hewlett-Packard Company Section 1M−−673