IBM 000-8697 User Manual

Operating OnLine

Select the Dbspaces menu, Mirror option.

Every OnLine blobspace and dbspace is listed. You can start mirror-
ing for spaces with a status of

N

. You can end mirroring for spaces

with a status of

Y

.

Use the

RETURN

 key or the arrow keys to select a blobspace or

dbspace. Press

CTRL-B

 or

F3

.

If the current status is

Y

,

DB-M

onitor ends mirroring and releases the

mirror chunks.

If the current status is

N

,

DB-M

onitor prompts you for the full path-

name location, offset, and size of each mirror chunk.

Informix recommends that you use a linked pathname. (Refer to

 for further information about the benefits of using linked

pathnames. Refer to

 for guidelines on how to determine

where your chunks should be located on disk.)

Specify an offset in the

Offset

 field if it is appropriate for your

device. (Refer to

 for further information about how to

determine if you need an offset.)

Enter the size of the chunk, in kilobytes, in the

Size

 field.

The size of the physical log is specified as

PHYSFILE

in the configuration file.

The dbspace location of the physical log is specified as

PHYSDBS

.

You can move the physical log file to try to improve performance. When
OnLine disk space is initialized, the disk pages allocated for the logical log
and the physical log are always located in the root dbspace. After OnLine is
initialized, you might be able to improve performance by physically
separating the physical log and the logical log and placing them on disks that
are not shared by active tables.

The space allocated for the physical log must be contiguous. If you move the
log to a dbspace without adequate contiguous space or increase the log size
beyond the available contiguous space, a fatal shared-memory error occurs
when you attempt to reinitialize shared memory with the new values.

Specify the size of the physical log in kilobytes.