blkmapd(8) — Linux manual page


blkmapd(8)                 System Manager's Manual                blkmapd(8)

NAME         top

       blkmapd - pNFS block layout mapping daemon

SYNOPSIS         top

       blkmapd [-h] [-d] [-f]

DESCRIPTION         top

       The blkmapd daemon performs device discovery and mapping for the
       parallel NFS (pNFS) block layout client [RFC5663].

       The pNFS block layout protocol builds a complex storage hierarchy
       from a set of simple volumes.  These simple volumes are addressed by
       content, using a signature on the volume to uniquely name each one.
       The daemon locates a volume by examining each block device in the
       system for the given signature.

       The topology typically consists of a hierarchy of volumes built by
       striping, slicing, and concatenating the simple volumes.  The blkmapd
       daemon uses the device-mapper driver to construct logical devices
       that reflect the server topology, and passes these devices to the
       kernel for use by the pNFS block layout client.

OPTIONS         top

       -h     Display usage message.

       -d     Performs device discovery only then exits.

       -f     Runs blkmapd in the foreground and sends output to stderr (as
              opposed to syslogd)


       The blkmapd daemon recognizes the following value from the [general]
       section of the /etc/nfs.conf configuration file:

              Tells blkmapd where to look for the rpc_pipefs filesystem.
              The default value is /var/lib/nfs/rpc_pipefs.

SEE ALSO         top

       nfs(5), dmsetup(8), nfs.conf(5)

       RFC 5661 for the NFS version 4.1 specification.
       RFC 5663 for the pNFS block layout specification.

AUTHORS         top

       Haiying Tang <>
       Jim Rees <>

COLOPHON         top

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                               11 August 2011                     blkmapd(8)

Pages that refer to this page: nfs.conf(5)