Welcome to the new DOCS.vastdata.com. We've added new menus and a version selector, plus new persona and resource pages to help customers get started. Looking for a previous article? Use the docs search.

Press CTRL+K to open search

NFS reference

Prev Next

Applies to VAST Cluster 5.5.

What VAST Cluster 5.5 supports over NFS, from the client's point of view. For how to use it in an application, see NFS for applications. Export, view policy and tenant settings are admin tasks; the KB links say where they're documented.

Versions

Version Supported Notes
NFSv3 Yes Mount by the view's path or its NFS alias. NLMv4 byte-range locks. POSIX ACLs (setfacl) when the view policy allows them.
NFSv4.1 Yes Built-in locking, NFSv4 ACLs (with the Mixed Last Wins flavor), ID mapping with Active Directory, Kerberos, file delegations.
NFSv4.2 Yes Everything in 4.1, plus extended attributes and security labels. Must be enabled for the tenant. Recommended version for delegations.
NFSv4.0 No A vers=4.0 mount fails with mount.nfs: Protocol not supported.

Features

Feature Versions What you need to know
nconnect 3, 4.1 Up to 16 TCP connections to one VIP. Recent Linux kernels, or the VAST-NFS driver.
NFS over RDMA 3, 4.1 InfiniBand or RoCE. VAST-NFS recommended on older distributions. TLS isn't supported over RDMA with 4.1.
Multipath 3, 4.1 Connections over a range of VIPs (remoteports=). Needs the VAST-NFS driver.
GPUDirect Storage with RDMA Through VAST-NFS.
Byte-range locks 3 (NLM), 4.1+ Advisory: a conflicting fcntl lock from another process fails, a lock on another range succeeds. A limited number of locks per file at once. Stale locks can be released by your platform team.
Extended attributes 4.2 user. namespace on Linux. Files and directories, not symlinks. Read and write need read and write permission (or the NFSv4 xattr access bits).
File delegations 4.1, 4.2 Set per tenant and per view. Need NTP on client and cluster and a backchannel; not supported for SLES 12 and CentOS 7 clients; VAST-NFS 4.0.32 or later if you use it. Close-to-open consistency only between NFSv4 clients. Recalled on failover.
NFSv4 ACLs 4.1+ Can be set by clients only with the Mixed Last Wins security flavor.
ID mapping 4.1+ User and group names as user@domain, with the client and cluster in the same Active Directory domain. Kerberos mounts always use it.
Kerberos 4.1+ krb5, krb5i, krb5p; a view policy can require integrity or privacy. MIT Kerberos providers serve NFSv4 only.
TLS and mTLS 3, 4 Encrypted NFS, and client certificates for tenant identification. For NFSv3 with mTLS: VAST-NFS and mountproto=tcp.
rquota 3 Read your quota; SETQUOTA isn't supported, nor quotas on NFS aliases.
Trash folder 3, 4.1 Move a directory to the trash for fast background deletion, if enabled.

Access rules that affect clients

  • Host rules. A view policy lists which client addresses may mount, read-write or read-only, per protocol. A mount from another address is refused with mount.nfs: access denied by server while mounting ....
  • Squash. Per host, the view policy can map root (root squash) or every user (all squash) to nobody, for NFSv3. If your files end up owned by nobody, this is the first thing to check. With the S3 Native flavor, a squashed root can't create files at all, even in a directory with mode 777.
  • Security modes. The view policy decides which RPC security flavors a mount may use: AUTH_SYS, and Kerberos krb5, krb5i or krb5p. It can require Kerberos, integrity or privacy.
  • Group sources. The view policy decides whether a user's groups come from the RPC (the client's GIDs), from the directory providers, or both.
  • Nested views. A view with NFSv4 needs NFSv4 on all views above it, including a view on / if the cluster has one. Otherwise VMS warns when the view is created, and an NFSv4.1 or 4.2 mount of it fails with mount.nfs: Operation not permitted. An NFSv4.1-only view under an NFSv3-only parent can be used through an existing mount but can't be mounted.
  • Unknown owners. With NFSv4, if the cluster can't resolve a file's user or group, GETATTR returns BADOWNER and the client shows nobody.

Names

By default a file or directory name can be up to 255 characters (File name too long beyond that), using only characters every supported protocol allows. A view policy can relax both. Extended-attribute names and values follow the same setting. See limits.

See also

Related articles