It’s sometimes a requirement to add a new high or low priority link to the existing LLT links. This can be done online without affecting any of the cluster services. There are 2 ways to do the same online (without offlining any service group).
1. Method 1 (using lltconfig)
2. Method 2 (editing /etc/llttab and restarting VCS using -force option)
1. Method 1 (using lltconfig)
Add/Remove High Priority LLT link
To add a high priority LLT link online (without restarting LLT) :
# lltconfig -t [device tag] -d [device]
Example :
# lltconfig -t eth2 -d eth2
To remove a High priority LLT link online (without restarting LLT) :
# lltconfig -u [devicetag]
Example :
# lltconfig -u eth2
Add/Remove Low Priority LLT link
The only change in case of adding or removing a low priority LLT link is the use of option -l :
# lltconfig -t [devicetag] -d [device] -l
Example :
# lltconfig -t eth2 -d eth2 -l
To remove a Low priority LLT link online (without restarting LLT) :
# lltconfig -u [devicetag]
2. Method 2 (editing /etc/llttab and restarting VCS using -force option)
This method uses a straight forward way of editing the /etc/llttab and the restarting VCS/fencing/GAB/LLT in order to changes to take effect.
1. Backup the llttab file and edit it to have the entry for low priority LLT link.
# cp /etc/llttab /etc/llttab.bak # vi /etc/llttab
2. Ensure the cluster configuration is read-only and restart VCS, leaving applications running on the nodes.
# haconf -dump -makero # hastop -all -force (on any one node) # gabconfig -a
3. Stop fencing on each node.
# /sbin/vxfen-shutdown # vxfenadm -d # gabconfig -a
4. Unconfigure GAB and LLT on each system
# gabconfig -U # lltconfig -U
5. Now start LLT and GAB on each node.
# lltconfig -c # sh /etc/gabtab
6. Start fencing on each node.
# /sbin/vxfen-startup
7. Now start VCS on each node and verify if everything is running fine.
# hastart