User Guide

4-2 Ampex 1308911-02
Model No.
Running Head
IntroductionTape Drive Operational CharacteristicsTape Drive Operational Characteristics
AIX
(device
special file *.0)
Same as DEC, HP, and Solaris, except implements the user-defined block size on
open.
SGI
(device special file
/tps Xdy)
Same as DEC, HP, and Solaris, except:
• On open, the tape drive is not reserved for exclusive use by current process.
• While open:
– 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.
– If a filemark is encountered during the first read after open and no data was
transferred, the filemark is ignored and the read command is re-issued.
Table 4-2. Tape Drive Behavior Required for tar and dd.
Platform Required Behavior
HP, DEC, Solaris, AIX
(device
special file *.9)
Same as described in Table 2-3, except:
• While open:
– When a filemark is detected during a read, 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 reports zero bytes.
– When Early Warning is detected during a write, flushes the tape drive buffer
to tape and reports zero bytes.
• On close, the current position is not changed. Since each utility opens and
closes the tape drive, this behavior is required so that a positioning utility can
be used to establish the current position from which tar or dd starts reading
from or writing to tape.
SGI
(device special file
/tps Xdy)
Same as described in Table 2-3, except the current position is not changed on
close. This behavior is required so that a positioning utility can be used to
establish the current position at which tar or dd starts reading from or writing to
tape.
Table 4-1. DST/DIS Tape Drive Basic Behavior (Continued)
Platform Default Actions