NFSv4

1

• NFSv4
• Namespace
• Migration
• Charles Fan
• Rainfinity

2
Three Global Namespaces

• Cluster Namespace
• Called global namespace vs. local node
  namespace
• Many vendor solutions exist
• Enterprise Namespace
• Global multi-site deployment
• Fit for protocol standards work
• World-Wide Namespace
• One namespace to rule them all

3
Requirements

• Location Independent
• Logical view into file storage, independent of
  physical locations
• Uniform Namespace
• Clients possess views into the same global
  namespace
• Transparent to Change
• When the mapping between the namespace and
  physical location changes, the namespace
  presentation stays constant and clients are not
  affected
• Secure
• At least the same level of security is maintained
  as without the namespace

4
Considerations

• Granularity
• File system? Directory? File?
• Hierarchical Mapping
• Map /a/b to one link and /a/b/c to another?
• Variable Support
• Map /tools to f1/tools_solaris for Solaris
  clients and f2/tools_linux for Linux clients?
• Manageability
• Multi-protocol interoperability
• Cycle Prevention

5
Based on Clients or Servers?

• Purely client-based
• Automounter LDAP
• Transparency concerns when namespace is changed
• Purely server-based
• Always in-band
• Scalability concerns for distributed enterprises
• Protocol-based
• Both server and clients comply with protocol
• Opportunity for highest level of transparency,
  scalability and interoperability.

6
Migration Issues

• Server-server protocol
• During migration
• Third party vendor solution possible
• Client-server protocol
• Namespace update after migration
• Protocol spec crucial
• File Handle Refresh
• Clients cache file names to look up again in new
  file system
• How to take care of the rename case?

7
Work Items

• Problem statement
• Schema for global namespace
• Client-server interaction for both referral case
  and migration case
• Clarification of RFC 3530
• Reference implementation of clients, servers and
  namespace server
• Possible minor version extensions
• Best Practice documents

8
Rainfinity Motivation

• Rainfinity relies on widely-adopted out-of-band
  global namespace solution for our Network File
  Virtualization architecture
• Currently work with MS Dfs, Automounters, etc
• Expect NFSv4 will enhance our functionality
• Rainfinity RainStorage provides transparent
  server-server migration and temporary client
  redirection.
• We hope that client-server interactions are built
  into clients and servers to handle permanent
  global namespace and dynamic change of data
  location
• Rainfinity is ready to commit resource to work
  with other companies to move fast on standards
  work related to global namespace and migrations

9
Thank You!