Set Parameters For Unstructured Files - HP T6553 D45 Reference Manual

FUP Commands

SET Parameters for Unstructured Files

The create-param set available depends on the type of file you want to create.
These options are available for unstructured files:
BUFFERSIZE unstructured-buffer-size
is the internal buffer size to use when accessing the specified file (for unstructured
files only). To set the BUFFERSIZE file attribute, use this command (FUP SET) or
the FUP ALTER and FUP CREATE commands. Possible values for
unstructured-buffer-size are (in bytes):
512, 1024, 2048, 4096
FUP rounds the actual buffer size up to the nearest valid DP2 block size.
During the file-creation process, DP2 rounds up the extent size (to 2 pages or
4,096 bytes) because the extent size of DP2 files must always be an integral
multiple of the BUFFERSIZE (for unstructured files) or of the BLOCK size (for
structured files).
To create an unstructured DP2 file with one-page extents, you must specify a
BUFFERSIZE of 2048 bytes with either the FUP SET or FUP CREATE command.
ODDUNSTR
changes an even unstructured file to an odd unstructured file.
Unstructured Enscribe files can be even or odd. The FUP process rounds up any
odd byte count that you give to an even unstructured file (for reading, writing, or
positioning). This is the default for unstructured files.
FUP does not round up odd unstructured files. You always read, write, or position
at the byte count you give. To change an odd unstructured file to an even
unstructured file, copy the odd file into a new file that was created as even
unstructured.
For unstructured files created on 512 byte sector disk enclosure, the primary and the
secondary extent values are rounded to a mod-14 number by DP2, and the
MAXEXTENTS parameter may be adjusted accordingly.
An extent page is 2 KB. When a non-partitioned unstructured file is created within or
migrated to the 512 byte sector disks, the extent sizes are rounded up to a mod-14
boundary (14 blocks of 2 KB size). The actual space allocated on disk includes a 4 KB
check block.
For each 28 KB of data of unstructured files on 512 byte sector disks, one 4 KB check
block with the checksum data is allocated. For extent management, check blocks are
added to the file size and extents are aligned to include check blocks. For I/O
management, all unstructured I/Os are in units of 32 KB (28 KB user data and 4 KB
check block).
File Utility Program (FUP) Reference Manual—523323-014
SET Parameters for Unstructured Files
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