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

r
rmt(1M) rmt(1M)
NAME
rmt - remote magnetic-tape protocol module
SYNOPSIS
/usr/sbin/rmt
DESCRIPTION
rmt is a program used by the remote dump and restore programs for manipulating a magnetic tape drive
through an interprocess communication
(IPC) connection. The fbackup and frecover commands
also use
rmt to achieve remote backup capability (see fbackup(1M) and frecover (1M)).
rmt is normally
started up with an
rexec() or rcmd() call (see rexec(3N) and rcmd(3N)).
rmt accepts requests specific to the manipulation of magnetic tapes, performs the commands, then
responds with a status indication. DDS devices that emulate magnetic tapes are also supported. All
responses are in ASCII and in one of two forms. Successful commands have responses of
Anumber\n
where number is an ASCII representation of a decimal number. Unsuccessful commands are responded to
with
Eerror-number \nerror-message
\n
where error-number is one of the possible error numbers described in errno(2) and error-message is the
corresponding error string as printed from a call to
perror() (see perror(3C)). The protocol is
comprised of the following commands:
Odevice\nmode\n Open the specified device using the indicated mode. device is a full path-
name and mode is an
ASCII representation of a decimal number suitable for
passing to open() (see open(2)). If a device is already open, it is closed
before a new open is performed.
odevice\nmode\n Open the specified device using the indicated mode. device is a full path-
name and mode is an
ASCII representation of an octal number suitable for
passing to open(). If a device is already open, it is closed before a new open
is performed.
Cdevice\n Close the currently open device. The device specified is ignored.
Lwhence\noffset \n Perform an lseek() operation using the specified parameters (see
lseek(2)). The response value is that returned from by lseek().
Wcount\n Write data onto the open device. rmt reads count bytes from the connec-
tion, aborting if a premature end-of-file is encountered. The response value
is that returned from by
write() (see write (2)).
Rcount\n Read count bytes of data from the open device. If count exceeds the size of
the data buffer (10 Kbytes), it is truncated to the data buffer size.
rmt then
performs the requested
read() and responds with Acount-read \n if the
read was successful. Otherwise an error is returned in the standard format.
If the read was successful, the data read is then sent.
Ioperation \ncount\n
Perform a MTIOCOP ioctl() command using the specified parameters.
Parameters are interpreted as ASCII representations of the decimal values to
be placed in the mt_op and mt_count fields of the structure used in the
ioctl() call. The return value is the count parameter when the operation
is successful.
S Return the status of the open device, as obtained with a MTIOCGET
ioctl() call. If the operation was successful, an ACK is sent with the size
of the status buffer, then the status buffer is sent (in binary).
s Return the status of the open device, as obtained with a fstat() call. If
the operation was successful, an ACK is sent with the size of the status buffer,
then the status buffer is sent (in binary). f Return the status of the open
device, as obtained with a fstat() call. If the operation was successful, an
ACK is sent with the size of the status buffer, then the status buffer is sent in
the following ASCII format:
HP-UX 11i Version 2: August 2003 − 1 − Hewlett-Packard Company Section 1M−−689