Increasing the number of hosts to which NIM can NFS-export a resource

Follow these instructions to increase the number of hosts to which NIM can NFS-export a resource.

By default, when NIM exports a file or directory through NFS during resource allocation, it creates an entry in the /etc/exports file granting the target host both client mount access and root access for root users. As a result, when exporting to numerous clients, the limit on the length of a line in the exports file (32767 characters) may be exceeded, resulting in failure.

NIM provides an option to decrease the line length of an allocation entry in an NFS exports file by approximately one-half, effectively permitting files to be allocated to a greater number of hosts. This action has the side effect of increasing the number of machines permitted in a NIM machine group. NIM achieves this by only granting root access to allocation target hosts. The client mount access list is not created, which allows any machine to mount the resource, but still restricts root access to NIM clients only. NFS permits no more than 256 host names in a root exports file entry.

To enable this mode of operation, set the restrict_nfs_exports attribute to no on the master's NIM object. Use the change operation as follows:
nim -o change -a restrict_nfs_exports=no master

To restore client mount access restrictions, set restrict_nfs_exports to yes with the change operation.

For information about how to export NIM resources globally, see Exporting NIM resources globally.