IBM Spectrum Scale NFS Cluster Export Services may experience NFSv3 access loss during upgrade from v4.2.1.x

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Problem summary

NFS configuration of IBM Spectrum Scale v4.2.1.x requires the SHORT_FILE_HANDLE option set to True in order to maintain compatibility with VMware. However, with IBM Spectrum Scale v4.2.2.0 and later, SHORT_FILE_HANDLE option must be set to False. An upgrade from IBM Spectrum Scale v4.2.1.x to v4.2.2.0 or higher level will result in loss of NFSv3 access to NFS cluster export services (CES) until NFS SHORT_FILE_HANDLE is set to False. An upgrade to IBM Spectrum Scale v4.2.3.3 or later may require a re-mount of NFSv3 for which no parameter change is required (parameter is removed).

Users affected

For users running NFS cluster export services on IBM Spectrum Scale v4.2.1.x (where .x is all levels), active NFSv3 connections may be affected during the following scenarios:

- Update to IBM Spectrum Scale 4.2.2.0 with NFSv3 in use and the SHORT_FILE_HANDLE option is set to True.
- Update to IBM Spectrum Scale 4.2.3.3 with NFSV3 in use and the SHORT_FILE_HANDLE option is set to True.

Recommendations

1) Any customer planning to upgrade should quiesce all NFS (and SMB and Object) workload to all CES nodes prior to the upgrade. This will help reduce the possibility of open files, due to CES file access, from causing a failure to unload GPFS and thus a subsequent reboot to recover.

2) For users running the update to IBM Spectrum Scale 4.2.2, after the upgrade is complete, set the NFS SHORT_FILE_HANDLE to False.

3) Unmount and remount NFSv3 clients after the upgrade.