Support for GPFS Immutable Fileset to be used from NFS exports

GPFS 3.5 and higher has built-in capabilities providing the SnapLock function to make files immutable (WORM protected). This function is based on immutable file sets but it not supported.

SnapLock essentially allows to make file immutable using standard file system command (chmod, touch). It is a function that has been developed by NetApp more than 10 years ago and is implemented on NetApps NAS filers. Many other storage vendors (EMC; Hitachi, HP) provide this function with their NAS system. IBM does not have a system providing this function.

The SnapLock function in GPFS has been developed for Information Archive. It allows to associate a file set with an Immutability attribute (basic, intermediate, maximum). File stored in such file set can be treated with the SnapLock method (chmod, touch) to automatically set the immutability or append-only flag either within GPFS or via an NFS export. It is not possible to reset the immutability or append-only flag for a file when the file set is in maximum. GPFS will also allow to set retention times (via touch -a) during which the file cannot be deleted.

This function is in GPFS and had been tested for IA. After IA was sunset this functions has not longer been pursued. This RFE ask to make this function supported with GPFS and also workable via an NFS export.