NAME

       blkmapd - pNFS block layout mapping daemon

SYNOPSIS

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

DESCRIPTION

       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

       -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)