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

2. Decide how much disk space the logical volume will need.
For example, you might be adding a new project that you expect to grow to 500MB.
In this case you need a volume with at least 1000MB of free space, 500MB for the
original and 500MB for the mirror copy.
3. Access the HP SMH Homepage.
4. Select Tools, Disks and File Systems, Volume Group. Select a volume group
that has as much free space as you need.
If you will be using strict mirroring (which HP recommends) the volume group
needs to contain a logical volume that has at least 500MB on each of two disks;
strict mirroring ensures that the mirror copy is on a separate disk from the original
data.
Look in the Free column; the numbers listed here represent the disk space in each
volume group that is not currently allocated to any logical volume.
You might see, for example, that volume group vg01 has 1800 MB of unallocated
space out of a total of about 2500 MB, and you might also see in the Detailed view
at the bottom of the page thatvg01 is spread across two disks. In this case it’s likely
that each disk has 500 MB free.
5. Click on the Logical Volumes tab at the top of the page. Select the Logical Volume
to be mirrored and click on the Add Mirror(s)... action on the right side of the
page. The Add Mirror(s) page is displayed.
6. Enter the number of mirrored data images desired (in this example one), and
desired options. 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.
7. 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.
Extending a Logical Volume
For detailed discussion of LVM (Logical Volume Manager) see HP-UX System
Administrator’s Guide: Logical Volume Management. The following example uses HP SMH.
1. Decide how much more disk space the logical volume will need.
For example, you might want to add 200 MB of swap, or an existing project might
need an additional 1000 MB.
Managing Disks - Quick Reference Examples 99