Monitoring Disk Resources

Rules for Using the EMS Disk Monitor with MC/ServiceGuard

links are not configured in separate PVGs, the disk monitor sees all links to the array as one physical volume, so if one link fails, pv_summary will register DOWN, and your package will fail over, even if the other link is still up and data is available.

The following sections describe how to make sure your PV links are in physical volume groups.

Adding PVGs to Existing Volume Groups

If you have already created volume groups, you can create PVGs and put PV links into them:

1. Create a file called /etc/lvmpvg with permissions 600. See the lvmpvg man

page and HP-UX System Administration Tasks

2. Create an entry for each volume group and assign a different PVG name to each PV link. The PVG names can be any arbitrary name of your choosing, but must be unique on the system For example, an array containing 2 volume groups, vgdance and vgsing, each containing a single LUN and each with 2 PV links (see Figure 2-4 on page 51) should have the following /etc/lvmpvg file:

VG /dev/vgdance PVG busA /dev/dsk/c1t0d0 /dev/dsk/c1t2d0 PVG busB /dev/dsk/c2t1d0 /dev/dsk/c2t3d0

VG /dev/vgsing PVG busA /dev/dsk/c1t0d1 /dev/dsk/c1t2d1 PVG busB

 

/dev/dsk/c2t1d1

 

/dev/dsk/c2t3d1

 

3. Carefully copy the /etc/lvmpvg to each system connected to the disk array.

 

 

NOTE

Make sure you edit lvmpvg to contain the correct link names in

 

/dev/dsk/device for that system.

 

 

Creating Volume Groups on Disk Arrays Using PV

Links

If you will be monitoring volume groups that use mass storage on disk arrays, you should use redundant I/O channels from each node, connecting them to separate controllers on the array. Then you can define alternate links to the LUNs or logical disks you have defined on the array. Alternate links (known as PV links) to the same disk should be assigned to different physical volume groups. In SAM, choose the

Chapter 2

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HP HA s Software manual Creating Volume Groups on Disk Arrays Using PV Links, Adding PVGs to Existing Volume Groups