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)

SEE ALSO         top

       nfs(5), dmsetup(8)

       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)