User Guide

Ampex 1308911-02 B-15
Device Special Files Introduction
Table B-6. DST/DIS Device Special Files Default Actions
Device Special File Interface Parameter Setting and Action Performed
Default Actions on Open
/dev/rmt/tpsXdY
/dev/rmt/tpsXdYnr
/dev/rmt/tpsXdYnm
/dev/rmt/tpsXdYnrnm
/dev/rmt/tpsXdYnrnf
/dev/rmt/tpsXdYnrnfnm
DST_SBLK_SIZE —
Off
Retains current block size.
DST_NO_OPN_CMD — Off
Clears outstanding Unit Attention conditions.
DST_DEF_POS_OPN and DST_RETEN_OPN — Off
The current position is not changed.
Note: To reposition the tape, use the DST_SETPOS ioctl.
DST_NO_RESERVE — On
Does not reserve tape drive for sole use by current process.
DST_OPEN_RDONLY- Controlled by O_RDONLY flag argument of open call.; see
Table B-8 for details
/dev/rmt/tpsXdYstat
DST_SBLK_SIZE, DST_DEF_POS_OPN, DST_RETEN_OPN, DST_NO_RESERVE,
and DST_OPEN_RDONLY — Same as for /dev/rmt/tpsXdY above
DST_NO_OPN_CMD — On
No Action Performed.
Default Actions While Open
/dev/rmt/tpsXdY
/dev/rmt/tpsXdYnr
/dev/rmt/tpsXdYnm
/dev/rmt/tpsXdYnrnm
/dev/rmt/tpsXdYstat
DST_APPEND_ONLY-
Controlled by O_APPEND flag argument of open call; see
Table B-8 for details.
DST_NO_REFORMAT- Off
Allows reformatting of tapes.
DST_IGN_FM - On
If a filemark is encountered during the first read command after open and no
data was transferred, the filemark is ignored and the read command is
re-issued.
DST_NO_FLUSH - Off
Filemarks written to tape are not buffered.
DST_ZERO_ON_FM — On
When a filemark is detected during a read operation, returns the number of
bytes read and sets the current position to after the filemark. If some data was
read before the filemark was detected, the next read operation reports zero
bytes.
Note: The application can recognize the filemark detected by retrieving and
diagnosing the Request Sense data.
DST_ZERO_ON_EW — Controls behavior when Early Warning is detected during
a read or write; see Table B-8 for details.