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Chapter 6
HPSS Configuration
Table 6-11 Storage Class Configuration Variables (Continued)
Display Field Name
Stripe Transfer Rate
Blocks Between Tape
Marks
Seconds Between Tape
Marks
Minimum Storage Segment
Size
Maximum Storage Segment
Size
310
Description
The approximate data
transfer rate for the entire
stripe.
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.
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.
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.
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 modifies the other
one. As a rule of thumb, it is best to choose "Blocks Between Tape Marks" such that
5 to 30 seconds elapse.
The smallest allocatable
unit of disk space. This
field is applicable to disk
storage classes only.
Advice: Care should be taken in selecting the Storage Segment Size. Consult Section
2.9.1.6 for considerations related to this selection.
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.
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.
September 2002
Acceptable Values
This value is calculated by SSM. It
is the product of the Device I/O
Rate and Stripe Width fields.
Any positive 32-bit integer value.
Any positive 32-bit integer value.
Click on the option menu button to
pop up a list of acceptable sizes.
Click on the option menu button to
pop up a list of acceptable sizes.
HPSS Installation Guide
Release 4.5, Revision 2
Default
Value
Same as
Device I/O
Rate.
Based on
selected
Media Type.
Based on
selected
Media Type.
Cluster
Length.
Same as
Storage
Segment Size.
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