The zidMode allows NSS to decide whether the ZID for a given volume can go beyond the 32-bit limit (0xffffffff). When you set the ZID mode to zid32, and if the volume's ZID reaches the 32-bit limit, you can no longer create a file or folder in that volume because NSS does not serve a new ZID.
To view the ZID mode for a given volume, go to the file, /_admin/Manage_NSS/Volume/<volumename>/VolumeInfo.xml and search for zidMode. The options are: zid32 or zid64.
Also, NSS provides an option to verify whether the volume is 64-bit ZID enabled or not. If the nextAllocatableZid for a given volume is greater than the 32-bit limit, it indicates that the volume is 64-bit ZID enabled. To verify, go to the file, /_admin/Manage_NSS/Volume/<volumename>/VolumeInfo.xml and search for zid64Enabled. The options are: true or false. If the nextAllocatableZid for a given volume is greater than 0xffffffff, the value is set to true. Otherwise, it is set to false.
To configure ZID mode in both local and shared volumes:
For local volumes, add zid32 in the mount option for the volume in /etc/fstab to restrict the ZID from crossing 32-bit limit.
For example:
VOLNAME /media/nss/VOLNAME nssvol noauto,rw,name=VOLNAME,zid32 0 0
Executing this command sets the ZID mode of a volume named VOLNAME to 32-bit ZID (zid32). After executing the command, you must unmount and mount the volume for the changes to take effect.
For shared volumes, add zid32 to the volume’s /opt in the resource load script to restrict the ZID from crossing the 32-bit limit. The load script changes must be done using the iManager Cluster plug-in. For more information, see OES 23.4: OES Cluster Services for Linux Administration Guide.
For example: If CPOOL is a cluster pool with a volume CVOL, then to set the CVOL’s ZID mode to 32-bit ZID, add the value to /opt in the pool cluster resource load script as follows:
exit_on_err ncpcon mount /opt=ns=long,zid32 CVOL=volumeID
After modifying the load script, you must take the pool cluster resource offline, then bring it online for the changes to take effect.
If the volume’s mount option does not contain the ZID mode (zidMode) option, then NSS sets the default ZID mode as follows:
For local volumes, the ZID mode is set to zid64 by default in both the homogeneous and mixed-node cluster environment.
For shared volumes, the ZID mode depends on the cluster node where the volume is available.
In a cluster environment, that is, nodes running on OES 2018 and later, the ZID mode is set to zid64 by default.
In a mixed-node cluster environment, if any node is running on OES version earlier than OES 2018, the ZID mode is set to zid32 by default.
However, when a shared volume with zidMode set to zid32 is migrated to a node that is force enabled to 64-bit ZID using the /ForceEnableZID64 command, then zidMode is set to zid64 by default on the migrated node.
For example, consider a three node cluster environment, with node A (OES 2018), node B (OES 2015 SP1), and node C (OES 2018 SP1). By default, the ZID mode sets to zid32 for a shared volume on node A. When a resource with the shared volume migrates to node B that is force enabled to 64-bit ZID using the /ForceEnableZID64 command, the zidMode for that shared volume is set to zid64 on the migrated node B.
You can still force enable the ZID mode to 64-bit ZID on a local or shared volume using the following command:
/ForceVolumeZid64Mode=<volumename>
This command is not persistent. When a server reboots, the setting returns to the default based on the environment where the volume is available. Even if you place the command in the /etc/opt/novell/nss/nssstart.cfg file, the command is not persistent.