pfs(4)

NAME

pfs, PFS — portable file system

DESCRIPTION

The Portable File System, or PFS, allows access to a variety of CD-ROM file systems. Currently supported file systems include: iso9660, high sierra, RockRidge Interchange.

The PFS package consists of 7 programs:

pfs_mountd: is responsible for maintaining local and remote mounts. It must be running on both PFS clients and PFS servers. The pfs_mountd program validates arguments, and spawns pfs_mountd.rpc.
pfs_mountd.rpc: is the RPC server code associated with pfs_mountd. It should not be executed directly.
pfsd: responds to all client requests for a given mounted CD-ROM file system. pfsd needs to be running on all systems designated as PFS servers. pfsd validates arguments, and spawns pfsd.rpc.
pfsd.rpc: is the RPC server code associated with pfsd. It should not be executed directly.
pfs_exportfs: makes local directories available for mounting by PFS clients.
pfs_mount: mounts CD-ROM file system locally or from server.
pfs_umount: unmounts CD-ROM file system locally or from server.

Client file access calls are converted to PFS protocol requests, and are sent to the server system over the network. The server receives the request, performs the actual file system operation, and sends a response back to the client.

The Portable File System operates in a stateful fashion using remote procedure (RPC - rfc1057) calls built on top of external data representation (XDR - rfc1014) protocol. The RPC protocol provides for version and authentication parameters to be exchanged for security over the network.

A server can grant access to a specific filesystem to certain clients by adding an entry for that filesystem to the server's /etc/pfs_exports file and running pfs_exportfs(1M).

A client gains access to that filesystem with the pfs_mount command. Once the filesystem is mounted by the client, the server issues a file handle to the client for each file (or directory) the client accesses or creates. If the disc is unmounted at the server, the file handles becomes stale, and remote requests will return stale file handle messages.

A server may also be a client with respect to filesystems it has mounted over the network, but its clients cannot gain access to those filesystems. Instead, the client must mount a filesystem directly from the server on which it resides.

ERRORS

Generally physical disk I/O errors detected at the server are returned to the client for action. If the server is down or inaccessible, the client will see the message:

PFS server host not responding, retrying...

It will retry 4 times, and then finally return failure.

WARNINGS

PFS is obsolete and no longer supported on any HP-UX release. Delivery of PFS interfaces will be discontinued in the next HP-UX release.

PFS, from Young Minds, Inc. (now defunct), was originally adopted by HP to provide accessibility to Rock Ridge Interchange file system format on iso9660 CD-ROM file systems. The equivalent functionality is now provided via the HP-UX CDFS file system type and HP-UX's standard file systems commands.

PFS has known functionality and performance problems. HP customers are urged to stop using the PFS interfaces, and move to accessing all CD-ROM file system formats by using the standard HP-UX commands, specifying the file system type as cdfs. For example, to mount a CD-ROM file system, use:

mount -F cdfs /dev/dsk/c0t0d4 /cdrom

There is no need to treat the cdfs file system type differently from any other file system type; therefore, no special daemons or commands are required to access the variety of CD-ROM file system formats.

See mount(1M) and mount_cdfs(1M).

AUTHOR

pfs was developed by Young Minds, Inc.

FILES

/etc/pfs_exports

pfs(4)

Technical documentation

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