Table 2-4 Suggested Block Sizes For Tape - IBM Hub/Switch Installation Manual

Disk Type
Fibre Channel
Attached
In Table 2-3:
• Disk Type is the specific type of media to which the values in the row apply.
• Media Block Size is the block size to use in the storage class definition. For disk, this value
should also be used when configuring the Mover devices that correspond to this media
type. Note that this value will not limit the amount of data that can be read from or written
to a disk in one operation—it is used primarily to perform block boundary checking to
ensure that all device input/output requests are block aligned. This value should
correspond to the physical block size of the disk device.
• Minimum Access Size is the smallest size data access requests that should regularly be
satisfied by the corresponding media type. Any accesses for less than the listed amount of
data will suffer severe performance degradation. A value of zero indicates that the media
is in general suitable for supporting the small end of the system's data access pattern.
• Minimum Virtual Volume Block Size is the smallest block size value that should be used
for the corresponding media type when physical volumes are combined to form a striped
virtual volume. A value smaller than that specified may result in severely degraded
performance when compared to the anticipated performance of the striped virtual volume.
• Note: When SCSI, SSA or Fibre Channel attached disks are combined to form striped
virtual volumes, the minimum access size should become—at a minimum—the stripe
width of the virtual volume multiplied by the virtual volume block size. If not, data access
will only use a subset of the striped disks and therefore not take full advantage of the
performance potential of the virtual volume.
2.9.1.12.2 Tape Media Parameters
Table 2-4 contains attributes settings for the supported tape storage media types.
Tape Type
Ampex DST-312
Ampex DST-314
IBM 3480
IBM 3490
HPSS Installation Guide
Release 4.5, Revision 2
Table 2-3 Suggested Block Sizes for Disk
Media Block Minimum
Size Access Size
4 KB 0

Table 2-4 Suggested Block Sizes for Tape

Media Block Size
1 MB
1 MB
32 KB
32 KB
September 2002
Chapter 2
Minimum
Virtual Volume
Block Size
1 MB
Blocks Between
Tape Marks
1024
1024
512
1024
HPSS Planning
Notes
1
Estimated Physical
Volume Size
50, 150, 330 GB
100, 300, 660 GB
200 MB
400 MB
99