Moving segment storage objects
This chapter discusses how and why to move segments.
What is segment moving?
A segment move is when a data segment is relocated to another
location on the underlying storage object. The new location of
the segment cannot overlap with the current segment location.
Why move a segment?
Segments are moved for a variety of reasons. The most compelling among
them is to make better use of disk freespace. Disk freespace is an unused
contiguous extent of sectors on a disk that has been identified by EVMS
as a freespace segment. A data segment can only be expanded by adding
sectors to the end of the segment, moving the end of the data segment
up into the freespace that immediately follows the data segment. However,
what if there is no freespace following the data segment? A segment or
segments could
be moved around to put freespace after the segment that is to be
expanded. For example:
The segment following the segment to be expanded can be moved
elsewhere on the disk, thus freeing up space after the segment that
is to be expanded.
The segment to be expanded can be moved into freespace where
there is more room for the segment to be expanded.
The segment can be moved into freespace that precedes the
segment so that after the move the data segment can be expanded into the freespace
created by the move.
Which segment manager plug-ins implement the move function?
The following segment manager plug-ins support the move function:
DOS
s390
GPT
Example: move a DOS segment
This section shows how to move a DOS segment:
Note
In the following example, the DOS segment manager has a single
primary partition on disk sda that is located at the very end of the disk.
We want to move it to the front of the drive because we want to expand
the segment but there is currently no freespace following the segment.
Using the EVMS GUI context sensitive menu
To move the DOS segment through the GUI context sensitive menu,
follow these steps:
From the Segments
tab, right click
sda1.
Click Move.
Select sda_freespace1.
Click Move.
Using Ncurses
To move the DOS segment, follow these steps:
Use Tab
to select the Disk Segments view.
Scroll down with the down arrow and
select sda1.
Press
Enter.
Scroll down with the down arrow and
select Move by pressing
Enter.
Use the spacebar to select
sda_freespace1.
Use Tab
to select Move and press
Enter.
Using the CLI
Use the
task command to move a DOS segment with the CLI.
task:Move,sda1,sda_freespace1