Managing HP Serviceguard for Linux, Tenth Edition, September 2012

2. On ftsys10, activate the volume group, mount the file system, write a date stamp
on to the shared file, and then look at the content of the file:
vgchange --addtag $(uname -n) vgpkgB
vgchange -a y vgpkgB
mount /dev/vgpkgB/lvol1 /extra
echo ‘Written by’ ‘hostname‘ ‘on’ ‘date‘ >> /extra/datestamp
cat /extra/datestamp
You should see something like the following, including the date stamp written by
the other node:
Written by ftsys9.mydomain on Mon Jan 22 14:23:44 PST 2006
Written by ftsys10.mydomain on Mon Jan 22 14:25:27 PST 2006
Now unmount the volume group again, and remove the tag you added in step 1:
umount /extra
vgchange -a n vgpkgB
vgchange --deltag $(uname -n) vgpkgB
NOTE: The volume activation protection feature of Serviceguard for Linux requires
that you add the tag as shown at the beginning of the above steps when you
manually activate a volume group. Similarly, you must remove the tag when you
deactivate a volume group that will be used in a package (as shown at the end of
each step). As of Serviceguard for Linux A.11.16.07, a tag matching the uname
-n value of the owning node is automatically added to each volume group defined
for a package when the package runs; the tag is deleted when the package is
halted. The command vgs -o +tags vgname will display any tags that are set
for a volume group.
Storing Volume Group Configuration Data
When you create volume groups, LVM creates a backup copy of the volume group
configuration on the configuration node. In addition, you should create a backup of
configuration data on all other nodes where the volume group might be activated by
using the vgcfgbackup command:
vgcfgbackup vgpkgA vgpkgB
If a disk in a volume group must be replaced, you can restore the old disk’s metadata
on the new disk by using the vgcfgrestore command. See “Replacing Disks” in the
“Troubleshooting” chapter.
Preventing Boot-Time vgscan and Ensuring Serviceguard Volume Groups Are Deactivated
By default, Linux will perform LVM startup actions whenever the system is rebooted. These
include a vgscan (on some Linux distributions) and volume group activation. This can
178 Building an HA Cluster Configuration