HP-UX System Administrator's Guide: Routine Management Tasks

Adding a Mirror for an Existing Logical Volume Using Non-strict Mirroring
For detailed discussion of mirroring see “Creating and Modifying Mirrored Logical
Volumes” in the HP-UX System Administrator’s Guide: Logical Volume Management. The
following example uses HP SMH.
1. Decide how many mirror copies you want. For the purposes of this example, we’ll
assume you want one mirror and the size of the logical volume is 500MB. There
will be two copies of the data, the original and a mirror copy.
2. Access the HP SMH Homepage.
3. Select Tools, Disks and File Systems, Volume Groups. A list of volume groups
will be displayed.
4. Select the volume group containing the logical volume you wish to mirror. This
will display a list of the logical volumes making up the volume group at the bottom
of the page along with free space in the volume group.
Look in the Free column of the volume group that you selected. Make sure the
volume group has enough free space for the mirror. In this example, an additional
500 MB.
If you want to use strict mirroring (which HP recommends because it keeps the
“mirror” data on a separate disk from the original data) refer to the next example.
5. Click on the Logical Volumes tab at the top of the page. This will display the
logical volumes.
6. Select the logical volume you want to mirror. This will display the logical volume
actions.
7. Click on the Add Mirror(s)... action on the right side of the page. The Add Mirror(s)
page is displayed.
8. Enter the number of mirrored data images desired (in this example one), and
desired options. Since you are using non-strict mirroring you can let the HP SMH
select the location for the mirror data. You can place the mirrored Logical Volume
on a different physical drive by clicking on Select PV(s)... This will display
available drives. Click Add.
9. If there is only one physical volume available you may need to change the Allocation
Policy setting for the logical volume to Non-Strict. The setting can be changed by
selecting the logical volume to be mirrored from the list on the Logical Volumes
page and clicking on the Modify LV...action on the right side of the page.
HP SMH will create a logical volume that occupies 500 megabytes on each logical
volume (the original data and a mirror copy). The Mirrors column of the Logical
Volumes page should now show “1” for the selected logical volume.
Managing Disks - Quick Reference Examples 109