p NFS Requirements 61 th IETF DC

p. NFS: Requirements 61 th IETF – DC November 10, 2004 p. NFS, 61 th IETF, DC 1

Þ Now Client Host Net Goal Client NFS v 4 Storage Net Storage Servers Host Net NFS Server Storage Servers • Now: requested data moves through NFS server • Goal: reply from NFS server enables parallel access to diverse storage servers (NFS, i. SCSI, FC, …) p. NFS, 61 th IETF, DC 2

p. NFS Requirements • In response to p. NFS Problem Statement – Draft-gibson-pnfs-problem-statement-01. txt • Bandwidth & capacity scaling – Beyond one network endpoint for file system – Server bypass for client access to storage • NFSv 4 minor extension desired • Extensible storage (backend) protocols – NFSv 3, NFSv 4, SCSI blocks, SCSI objects p. NFS, 61 th IETF, DC 3

p. NFS Reqs - NFS extensions • Industry-wide open standard • NFSv 4 minor extension desired – No change to existing commands/results – New operations added via compound – Complimentary to, no dependence on RDMA p. NFS, 61 th IETF, DC 4

p. NFS Reqs - Scalability • Respond to scalable cluster computing • Scalable bandwidth wrt to total resources – Aggregate BW to files in one FS, one directory – Individual BW to single large files – Employ multiple network endpoints at storage • Scalable capacity wrt to total resources – Size of FS, directory, file can scale with storage p. NFS, 61 th IETF, DC 5

p. NFS Reqs - Interoperability • p. NFS endpoints talk to non-p. NFSv 4 • Storage protocol interoperability – Well defined storage protocol standards – Multiple different storage protocols, extensible • SBC (SCSI blocks), OSD (SCSI objects), NFSv. X • Separability of storage protocols – NFSv 4 extension operation does not need to interpret “layout state” specific to storage p. NFS, 61 th IETF, DC 6

p. NFS Reqs - Concurrent Sharing • Many clients access storage at same time – At device and file level • Change visibility can be asserted by client – Data & attribute change visibility not always determined • No assertion of client cache coherence – Logic modeled on Direct access mode p. NFS, 61 th IETF, DC 7

p. NFS Reqs - Recovery • Seek simple semantics to enable less complex implementations, interoperability – Slow recovery permissible, fast recovery possible • Client recovery may be “notify & retry” – Retry may be equivalent operation using only NFSv 4 – Storage operations should be idempotent p. NFS, 61 th IETF, DC 8

p. NFS Reqs - Security • Security comparable to NFSv 4 allowed • Security model for storage must be well defined – Trusted storage environments not ruled out, but must be well documented – Files: ACLs consistent over servers – Objects: OSD secure capabilities – Blocks: SAN access control tools (zoning, FC ACLs) p. NFS, 61 th IETF, DC 9

p. NFS Reqs - IANA • Need to name storage protocols • Divide namespace – 1) Reserved for this standard to define – 2) Reserved for vendor defined – 3) Open for in-house customer defined, nonunique • Storage naming defined by storage protocol p. NFS, 61 th IETF, DC 10