Chapter 6 HPSS Configuration
310 September 2002 HPSS Installation Guide
Release 4.5, Revision 2
Stripe Transfer Rate The approximate data
transfer rate for the entire
stripe.
This value is calculated by SSM. It
is the product of the Device I/O
Rate and Stripe Width fields.
Same as
Device I/O
Rate.
Blocks Between Tape
Marks The maximum number of
data blocks that can be
written on a tape between
consecutive tape marks.
This field is applicable to
tape storage classes only.
Any positive 32-bit integer value. Based on
selected
Media Type.
Advice: The number of blocks between the physical volume tape marks should be
chosen to use the media efficiently while allowing for quick positioning to a tape
mark. See Section 2.9.1.5 for more details.
Seconds Between Tape
Marks The number of seconds
between tape mark writes
during a tape write
operation derived from
Blocks Between Tape
Marks and Device I/O
Rate. This field is
applicable to tape storage
classes only.
Any positive 32-bit integer value. Based on
selected
Media Type.
Advice: Enter a value into the Blocks Between Tape Marks field, and use Seconds
Between Tape Marks value for feedback on the resulting time interval; or enter a
value into the Seconds Between Tape Marks and let SSM calculate the Blocks
Between Tape Marks value. Changing either field automatically modi��es the other
one.As a rule of thumb, it is best to choose “Blocks Between Tape Marks” such that
5 to 30 seconds elapse.
MinimumStorage Segment
Size The smallest allocatable
unit of disk space. This
field is applicable to disk
storage classes only.
Click on the option menu button to
pop up a list of acceptable sizes. Cluster
Length.
Advice:Care should be taken in selecting the Storage Segment Size. Consult Section
2.9.1.6 for considerations related to this selection.
MaximumStorage Segment
Size When this field is larger
than the Storage Segment
Size, the Bitfile Server is
allowed to use multiple
storage segment sizes for
disks in this storage class,
up to this maximum.
Click on the option menu button to
pop up a list of acceptable sizes. Same as
Storage
Segment Size.
Advice: If a value larger than 10 percent of PV Size is specified, the user will be
warned of non-optimal use of disk space.
Table 6-11 Storage Class Configuration Variables (Continued)
Display Field Name Description Acceptable Values Default
Value