blkmapd
Section: Maintenance Commands (8)
Updated: 11 August 2011
Page Index
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>