| .\" |
| .\" Copyright 2011, Jim Rees. |
| .\" |
| .\" You may distribute under the terms of the GNU General Public |
| .\" License as specified in the file COPYING that comes with the |
| .\" nfs-utils distribution. |
| .\" |
| .TH blkmapd 8 "11 August 2011" |
| .SH NAME |
| blkmapd \- pNFS block layout mapping daemon |
| .SH SYNOPSIS |
| .B "blkmapd [-d] [-f]" |
| .SH DESCRIPTION |
| The |
| .B blkmapd |
| daemon performs device discovery and mapping for the parallel NFS (pNFS) block layout |
| client [RFC5663]. |
| .PP |
| The pNFS block layout protocol builds a complex storage hierarchy from a set |
| of |
| .I 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. |
| .PP |
| The topology typically consists of a hierarchy of volumes built by striping, |
| slicing, and concatenating the simple volumes. |
| The |
| .B 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. |
| .SH OPTIONS |
| .TP |
| .B -d |
| Performs device discovery only then exits. |
| .TP |
| .B -f |
| Runs |
| .B blkmapd |
| in the foreground and sends output to stderr (as opposed to syslogd) |
| .SH SEE ALSO |
| .BR nfs (5), |
| .BR dmsetup (8) |
| .sp |
| RFC 5661 for the NFS version 4.1 specification. |
| .br |
| RFC 5663 for the pNFS block layout specification. |
| .SH AUTHORS |
| .br |
| Haiying Tang <Tang_Haiying@emc.com> |
| .br |
| Jim Rees <rees@umich.edu> |
