Quick File Access - Tandberg Data SLR7-140 PROGRAMMER Manual

Tandberg Data
2.3.4.

Quick File Access

Partitions can be used to support the implementation of
QFA (Quick File Access). QFA is a feature which provides
support for two partitions on a volume, a directory
partition and a
initiator is not allowed to specify the size of those
partitions. Only the number of partitions (one or two)
can be specified.
The QFA mode can be enabled and disabled with the FDP
bit of the Medium Partition Page(1). When not in QFA
mode the Drive
covering the whole tape. This single partition is called
the Default Data Partition.
Note that QFA is only supported when the medium to be
partitioned is a SLRtape140 to SLRtape7 or SLR32 medium.
Partition
0
1
Table 2-3:
In QIC compatible tape streamers like the Tandberg SLR
Product Line Tape Drives, all partitions start on track
set boundaries at the physical BOT end of the tape. Two
track sets (a total of 4 tracks) are allocated to the
directory partition when using the SLR6, QIC-5010-DC,
MLR3 or ALRF-2 tape formats. For the ALRF-1 and ALRF-6
tape format two track sets (a total of 8 tracks) are
allocated. All remaining track sets are allocated to the
data partition.
The following table
allocation for all supported tape formats:
Medium Type
SLRtape140
SLRtape100
SLRtape75
SLRtape60
SLRtape50
SLRtape40
SLRtape7
SLR32
SLRtape24
Table 2-4:
When the medium has been identified the Medium Partition
Page(1) returned by a MODE SENSE command may indicate
the actual partitioning on the currently mounted volume
(the number and size of each partition). When the medium
has not been
Defined and the Partition Size Descriptor fields are
undefined.
Note that the partition size(s) returned by a MODE SENSE
command are estimated sizes. The sizes are based on the
calculated capacity for a given number of tracks. The
actual size achieved may differ from the estimated size
due to such factors
2-11 Tandberg SLR Product Line SCSI Functional Specifications
data partition.
will implement
Directory Information
Partitions Within A QFA Volume
shows the
Approximate Size
2916 MBytes
2083 MBytes
1563 MBytes
1250 MBytes
694 MBytes
833 MBytes
1111 MBytes
444 MBytes
333 MBytes
Directory Track set Allocation
identified the
as tape length
About Tape Streamers
When using QFA
a single partition
Use
Data
directory track
Directory Track (Set) Number
46 and 47
46 and 47
46 and 47
46 and 47
70 and 71
46 and 47
34 and 35
70 and 71
70 and 71
Additional Partitions
variations,
the
set
the