Managing HP Serviceguard A.11.20.20 for Linux, March 2014

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.
5.1.12.8 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.
5.1.12.8.1 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 cause problems for
volumes used in a Serviceguard environment (for example, a volume group for a Serviceguard
package that is not currently running may be activated). To prevent such problems, proceed as
follows on the various Linux versions.
NOTE: You do not need to perform these actions if you have implemented volume-group activation
protection as described under “Enabling Volume Group Activation Protection” (page 148).
SUSE Linux Enterprise Server
Prevent a vgscan at boot time by removing the /etc/rc.d/boot.d/S07boot.lvm file from
all cluster nodes.
152 Building an HA Cluster Configuration