1. Take note of current HA configuration
1. Current metadata IPs, should you want the last octet to remain the same
2. Any other service IPs, such as a "floating" service on non-metadata LAN
3. Power control BMC/IPMI settings
4. MDC currently in control (I believe we left it on MDC1 earlier this week)
2. Unmount all clients
1. Unmount FC clients
2. Stop SONG cluster from "SONG" tab of :82 GUI (this will end all SMB sessions)
3. Verify no clients are mounted with bwclstat -l command on active MDC
3. Begin downtime, and start any other network modifications, likely including:
1. Modify client IP addresses
2. In HyperFS client, delete old MDC service address
3. Add new MDC service address
4. Modify any switches, routers, VLANs, etc. (you'll know this step better than me)
4. Log into active MDC :82 GUI using its dedicated IP, not the service address
5. Stop all filesystems
6. Stop HyperFS HA service
7. Delete HyperFS HA configuration
8. Change MDC1 metadata IP
1. Log into local console via IPMI/BMC, or local VGA console (SSH over non-metadata network is fine, though a little risky)
2. Login to local desktop session and open terminal, or press Ctrl+Alt+F2 for CLI
3. Gain root, if not already
4. Determine the logical interface being used for metadata using ip a
5. Edit the configuration script for the interface, for example /etc/sysconfig/network-scripts/ifcfg-bond0 (Use whatever Linux text editor you are comfortable with, like vim, nano, emacs)
6. Modify the value of IPADDR and any other parameters that will be changing
7. Save and close the file
8. Restart the network service with service network restart
9. Ping MDC1 over new metadata network to verify functionality
10. Change MDC2 metadata IP using the same steps as above
11. Ping MDC2 to check it
12. Re-open :82 GUI of MDC that was last-active
13. Reconfigure HA using the information gathered in step #1, but using the new metadata IP information
14. Start HA
15. Remount clients (using the MDC IP that was set in step #3.3) and verify functionality
16. End downtime