Managing HP Serviceguard A.11.20.00 for Linux, June 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 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 133).
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.
Preparing Your Systems 137