How to use Nested Mount File System (NMFS)


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How to use Nested Mount File System (NMFS)



An NMFS allows you to manage a collection of component file systems as a single file system. CIFS and NFS clients see component file systems as a single share or single export. File system capacity is managed independently for each component file system. This means that you can increase the total capacity of the NMFS by extending an existing component file system or by adding new component file systems. The number of NMFS or component file systems is limited only to the number of file systems allowed on a Data Mover. Hard links (NFS), renames, and simple moves are not possible from one component file system to another.


The Celerra features that support NMFS are:


  • SnapSure
  • Replicator
  • Quotas
  • Security policies
  • Backup
  • EMC Symmetrix Remote Data Facility (SRDF)
  • TimeFinder/FS
  • MPFS access to MPFS-enabled file systems
  • CDMS
  • FileMover
  • EMC MirrorView/Synchronous (MV/S)


Example :


$ nas_fs -name nmfs -type nmfs -create
$ server_mountpoint server_2 -create /nmfs
$ server_mount server_2 -o ro nmfs /nmfs
$ server_export server_2 -name nmfs /nmfs
$ server_mountpoint server_2 -create /nmfs/nmfs1
$ server_mountpoint server_2 -create /nmfs/nmfs2
$ nas_fs -name nmfs2 -create size=10G pool=clar_r5_performance
$ nas_fs -name nmfs1 -create size=10G pool=clar_r5_performance
$ server_mount server_2 nmfs1 /nmfs/nmfs1
$ server_mount server_2 nmfs2 /nmfs/nmfs2

In this case when the client mounts the "nmfs" share, it will see a 20 GB file system, and two subdirectories underneath it (nmfs1 and nmfs2).