NAME

segment - Sets segment file attributes

SYNOPSIS

segment [-d] [-f] [-s stage_ahead] [-V] -l segment_size filename …

segment [-d] [-f] [-s stage_ahead] [-V] -l segment_size -r dirname …| [ filename …]

AVAILABILITY

SUNWsamfs

DESCRIPTION

The segment command sets the segment attribute for an existing file. At a minimum, the -l segment_size and the filename must be specified. If a file is segmented, it is archived to and staged from its volumes in segment_size chunks.

When file attributes are set on a directory, files and directories subsequently created in that directory inherit those attributes.

The segment command is not supported in Oracle HSM shared file systems.

OPTIONS

-d

Returns the segment attributes on the file to the default. When -d is specified, attributes are first reset to the default, then other attribute-setting options are processed. It not possible to reset a file that has already been segmented.

-f

Suppresses errors.

-l segment_size

Specifies the segment size. The segment_size must be an integer and must be greater than or equal to one megabyte. The integer specified must be followed by k (for kilobytes), m (for megabytes), or g (for gigabytes). For example:

-l 1024k

This segment size specifies the size at which the file is segmented on the file system for archiving and staging. A file is segmented when it reaches the specified segment size. If a file has already been segmented, the segment size cannot be changed. A pre-existing file cannot be segmented if it exceeds the specified segment size.

-s stage_ahead

Specifies the number of segments to stage ahead when staging a segmented file. This means when an offline segment is read, in addition to staging the current segment, the next stage_ahead segments are also staged. The default value of stage_ahead is zero, which means there is no stage read ahead. The maximum stage_ahead value is 255.

-r

Recursively sets the segment file attribute for all files contained in the specified dirname or its subdirectories.

-V

Enables the verbose display. Displays a message for each file on which attributes are set.

NOTES

The file system disables quotas at mount time if any of the following files in the file system's root directory are segmented:

.quota_a
.quota_g
.quota_u

The -drives directive in the archiver.cmd file specifies the number of drives to use for archiving and staging.

The mmap function cannot be carried out on a segmented file. Because of this, a segmented file cannot be an executable binary.

Segmentation of files is not supported on an Oracle HSM shared file system.

A segmented file is automatically striped across several volumes when it is archived if the following conditions are in effect:

More than one drive is available.
The -drives directive is in effect.

A segmented file is automatically striped from several volumes when it is staged if the following conditions are in effect:

The file was archived as striped.
More than one drive is available.
The -drives directive is in effect.