HP-UX Reference (11i v1 00/12) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)
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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man7/!!!intro.7
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m
mt(7) mt(7)
GMT_D_QIC_525(x) Returns TRUE if the density encoded in mt_gstat is QIC-525 format.
GMT_D_QIC_1000(x) Returns TRUE if the density encoded in mt_gstat is QIC-1000 format.
GMT_D_QIC_1350(x) Returns TRUE if the density encoded in mt_gstat is QIC-1350 format.
GMT_D_QIC_2100(x) Returns TRUE if the density encoded in mt_gstat is QIC-2100 format.
GMT_D_QIC_2GB(x) Returns TRUE if the density encoded in mt_gstat is QIC-2GB format.
GMT_D_QIC_5GB(x) Returns TRUE if the density encoded in mt_gstat is QIC-5GB format.
GMT_D_8MM_8200(x) Returns TRUE if the density encoded in mt_gstat is 8 millimeter 8200
format (with or without compression).
GMT_D_8MM_8200c(x) Returns TRUE if the density encoded in mt_gstat is 8 millimeter 8200
format with compression.
GMT_D_8MM_8500(x) Returns TRUE if the density encoded in mt_gstat is 8 millimeter 8500
format (with or without compression).
GMT_D_8MM_8500c(x) Returns TRUE if the density encoded in mt_gstat is 8 millimeter 8500
format with compression.
GMT_MEDIUM(x) Identifies the 8-bit medium type value describing the tape currently loaded
into the tape device. The reported value is only valid for QIC and 8mm
devices. Supported values are defined in <sys/mtio.h >.
GMT_QIC_MEDIUM(x) Returns the same information as does GMT_MEDIUM(x).
GMT_MEDIUM(x) is preferred because GMT_QIC_MEDIUM may be
obsoleted at some future date.
GMT_DR_OPEN(x) Does not apply to any currently supported devices. Always returns FALSE.
HP-UX silently enforces a tape record blocking factor (MAXPHYS) on large I/O requests. For example, a user
write request with a length of ten times MAXPHYS will actually reach the media as ten separate records. A
subsequent read (with ten times MAXPHYS as a length) will look like a single operation to the user, even
though HP-UX has broken it up into ten separate read requests to the driver. The blocking function is tran-
sparent to the user during writes. It is also transparent during reads unless:
• The user picks an arbitrary read length greater than MAXPHYS.
• The user attempts to read a third-party tape containing records larger than MAXPHYS.
Since the value for MAXPHYS is relatively large (usually >= 256K bytes), this is typically not a problem.
The MTNOP operation does not set the device-independent status word.
3480 stacker devices are supported only in auto (that is, sequential-access) mode. To advance to the next
tape in the stack, an MTIOCTOP control request specifying an MTOFFL operation should be issued. An
MTIOCGET control request should then be issued to determine whether or not the stacker has been suc-
cessfully advanced. Failure on the MTIOCGET operation (or an offline status) indicates that no more tapes
are available in the stacker, the stacker has been ejected, and user intervention is required to load a new
stack.
EXAMPLES
Assuming that fd is a valid file descriptor, the following example writes two consecutive filemarks on the
tape:
#include <sys/types.h>
#include <sys/mtio.h>
struct mtop mtop;
mtop.mt_op = MTWEOF;
mtop.mt_count = 2;
ioctl(fd, MTIOCTOP, &mtop);
If fd is a valid file descriptor for an open DDS drive, the following example spaces forward to just past the
next setmark:
#include <sys/types.h>
#include <sys/mtio.h>
Section 7−−76 − 6 − HP-UX Release 11i: December 2000
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