Removing existing NSD Nodes from the GPFS Cluster is not difficult, but there are several steps to take note of.
Step 1: Check and make sure the NSD Nodes you are removing are not quorum-manager.
See Removing Quorum Manager from NSD Nodes
Step 2: Check that Quorum-Manager have been removed from the old NSD
# mmlscluster GPFS cluster information ======================== GPFS cluster name: mygpfs.gpfsnsd1 GPFS cluster id: 720691660936079521 GPFS UID domain: mygpfs.gpfsnsd1 Remote shell command: /usr/bin/ssh Remote file copy command: /usr/bin/scp GPFS cluster configuration servers: ----------------------------------- Primary server: newnsd3 Secondary server: newnsd4 ..... ..... ..... ..... 714 oldnsd1 192.168.111.5 oldnsd1 715 oldnsd2 192.168.111.6 oldnsd2 716 newnsd3 192.168.111.7 newnsd3 quorum-manager 717 newnsd4 192.168.111.8 newnsd4 quorum-manager
Step 3a: Umount the GPFS File System
# mmumount all -a
Step 3b: Check all the GPFS nodes have been unmounted
# mmlsmount all File system gpfs0 is mounted on 0 nodes.
Step 4: Displays Network Shared Disk (NSD) information for the GPFS cluster.
# mmlsnsd File system Disk name NSD servers --------------------------------------------------------------------------- gpfs0 dcs3700A_2 File system Disk name NSD servers --------------------------------------------------------------------------- gpfs0 dcs3700A_2 newnsd3,oldnsd1 gpfs0 dcs3700A_3 newnsd3,oldnsd1 gpfs0 dcs3700A_4 newnsd3,oldnsd1 gpfs0 dcs3700A_5 newnsd3,oldnsd1 gpfs0 dcs3700A_6 newnsd3,oldnsd1 gpfs0 dcs3700A_7 newnsd3,oldnsd1 gpfs0 dcs3700B_2 newnsd4,oldnsd2 gpfs0 dcs3700B_3 newnsd4,oldnsd2 gpfs0 dcs3700B_4 newnsd4,oldnsd2 gpfs0 dcs3700B_5 newnsd4,oldnsd2 gpfs0 dcs3700B_6 newnsd4,oldnsd2 gpfs0 dcs3700B_7 newnsd4,oldnsd2
Step 5: Changes Network Shared Disk (NSD) configuration attributes.
# mmchnsd dcs3700A_2:newnsd3
To confirm the changes, issue this command:
# mmlsnsd -d dcs3700A_2 File system Disk name NSD servers --------------------------------------------------------------------------- gpfs0 dcs3700A_2 newnsd3
Do for the rest…..
# mmchnsd dcs3700A_3:newnsd3 # mmlsnsd -d dcs3700A_3 # mmchnsd dcs3700A_4:newnsd3 # mmlsnsd -d dcs3700A_4 # mmchnsd dcs3700A_5:newnsd3 # mmlsnsd -d dcs3700A_5 # mmchnsd dcs3700A_6:newnsd3 # mmlsnsd -d dcs3700A_6 # mmchnsd dcs3700A_7:newnsd3 # mmlsnsd -d dcs3700A_7 # mmchnsd dcs3700B_2:newnsd4 # mmlsnsd -d dcs3700B_2 # mmchnsd dcs3700B_3:newnsd4 # mmlsnsd -d dcs3700B_3 # mmchnsd dcs3700B_4:newnsd4 # mmlsnsd -d dcs3700B_4 # mmchnsd dcs3700B_5:newnsd4 # mmlsnsd -d dcs3700B_5 # mmchnsd dcs3700B_6:newnsd4 # mmlsnsd -d dcs3700B_6 # mmchnsd dcs3700B_7:newnsd4 # mmlsnsd -d dcs3700B_7
Step 6: Remove Old NSD Nodes
Once you have confirmed that the NSD nodes are ok.
# mmdelnode -N oldnsd1,oldnsd2
Verify that the old NSD nodes are no more in the cluster
# mmlscluster
Step 7: Remount the File System
# mmmount all -a
References:
The Linux Cluster 