man 8 blkmapd

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

NAME
       blkmapd - pNFS block layout mapping daemon

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

DESCRIPTION
       The blkmapd daemon performs device discovery and mapping for the paral-
       lel 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 con-
       tent, 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
       -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)

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

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

SEE ALSO
       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
       Haiying Tang <Tang_Haiying@emc.com> 
       Jim Rees <rees@umich.edu> 

                                11 August 2011                      blkmapd(8)