Initial release | 17 June 2005Linux Kernel 2.6.12 |
---|---|
Repository | https://git.opensvc.com/gitweb.cgi?p=multipath-tools%2F.git;a=log |
Written in | C |
Operating system | Linux |
Device Mapper Multipath Input Output often shortened to DM-Multipathing and abbreviated as DM-MPIO provides input-output (
I/O) fail-over and
load-balancing by using
multipath I/O within
Linux for
block devices.
[1]
[2]
[3] By utilizing device-mapper, the multipathd
daemon provides the host-side logic to use multiple paths of a redundant
network to provide continuous availability and higher-
bandwidth connectivity between the host server and the block-level device.
[4] DM-MPIO handles the rerouting of block I/O to an alternate path in the event of a path failure. DM-MPIO can also balance the I/O load across all of the available paths that are typically utilized in
Fibre Channel (FC) and
iSCSI
SAN environments.
[5]
DM-MPIO is based on the
device mapper,
[6] which provides the basic framework that maps one block device onto another.
When utilizing Linux DM-MPIO in a datacenter that has other operating systems and multipath solutions, key components of path management must be considered.
DM-MPIO started as a patch set created by Joe Thornber, and was later maintained by Alasdair G Kergon at Red Hat. It was included in mainline Linux with kernel version 2.6.12, which was released on June 17, 2005. [7]
DM-MPIO in Linux consists of kernel components and user-space components.
dm-multipath
– kernel module implementing the multipath device-mapper target.The configuration file /etc/multipath.conf makes many of the DM-MPIO features user-configurable. The multipath command and the kernel daemon multipathd use information found in this file. The file is only consulted during the configuration of the multipath devices. Changes must be made prior to running the multipath command. Changes to the file afterward will require multipath to be executed again.
The multipath.conf has five sections: [8]
Initial release | 17 June 2005Linux Kernel 2.6.12 |
---|---|
Repository | https://git.opensvc.com/gitweb.cgi?p=multipath-tools%2F.git;a=log |
Written in | C |
Operating system | Linux |
Device Mapper Multipath Input Output often shortened to DM-Multipathing and abbreviated as DM-MPIO provides input-output (
I/O) fail-over and
load-balancing by using
multipath I/O within
Linux for
block devices.
[1]
[2]
[3] By utilizing device-mapper, the multipathd
daemon provides the host-side logic to use multiple paths of a redundant
network to provide continuous availability and higher-
bandwidth connectivity between the host server and the block-level device.
[4] DM-MPIO handles the rerouting of block I/O to an alternate path in the event of a path failure. DM-MPIO can also balance the I/O load across all of the available paths that are typically utilized in
Fibre Channel (FC) and
iSCSI
SAN environments.
[5]
DM-MPIO is based on the
device mapper,
[6] which provides the basic framework that maps one block device onto another.
When utilizing Linux DM-MPIO in a datacenter that has other operating systems and multipath solutions, key components of path management must be considered.
DM-MPIO started as a patch set created by Joe Thornber, and was later maintained by Alasdair G Kergon at Red Hat. It was included in mainline Linux with kernel version 2.6.12, which was released on June 17, 2005. [7]
DM-MPIO in Linux consists of kernel components and user-space components.
dm-multipath
– kernel module implementing the multipath device-mapper target.The configuration file /etc/multipath.conf makes many of the DM-MPIO features user-configurable. The multipath command and the kernel daemon multipathd use information found in this file. The file is only consulted during the configuration of the multipath devices. Changes must be made prior to running the multipath command. Changes to the file afterward will require multipath to be executed again.
The multipath.conf has five sections: [8]