HP 3000 Manuals HP 3000 Manuals
Extents (changed)
MPE V/E and MPE XL allocate extents differently, as summarized below:
In MPE V/E: | In MPE XL:
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When you build a file, at least one extent | Building a file does not necessarily
is allocated at build time. | allocate any disk space. Initial extents
| are only allocated if they are specified at
| creation time.
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Every file takes up some disk space, even | Empty files take up no disk space, unless
if it is empty. | initial extents are specified when the file
| is created.
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Files can be broken up into as many as 32 | Files can be broken into as many extents as
extents. The number and size of the | are needed. The number and size of the
extents is specified at the time the file | extents need not be specified at the time
is created. | the fiile is created. MPE XL will add
| extents to a file as required. Files can
| be built in one extent, or in a variable
| number of extents. Specifying a fixed
| number of extents (other than one) results
| in the allocation of a variable number of
| extents.
|
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Every file is described by a file label, | Every file is described by a file label,
which is stored by the operating system | which is part of a table called the File
along with the first extent. | Label Table (FLT). There is one FLT for
| each disk volume. The file label is not
| part of any extent of the file.
|