multipath-tools

Homepage of the upstream project used to drive the Device Mapper multipathing driver.
As multipathing rhymes with clustering, you might be interested in opensvc GPL clustering stack.

Contacts :

• christophe.varoqui@opensvc.com
• dm-devel@redhat.com

Contribute :

You can contribute code, editorial work and testing.
If you are in such position, you can also contribute hardware or hardware access.

git repository :

mkdir -p ~/scm/multipath-tools.upstream
cd ~/scm/multipath-tools.upstream
git-clone http://kernel.org/pub/scm/linux/storage/multipath-tools/.git

gitweb project reporting :

http://www.kernel.org/git/gitweb.cgi?p=linux/storage/multipath-tools/.git

build :

On debian based systems :

apt-get install libreadline-dev libaio-dev libdevmapper-dev
make

Documentation :

• ReferenceBook
• FAQ
• Policies
• Diagrams dia source here
• RedHat package Usage file

Latest release :

multipath-tools-0.4.9.tar.bz2

incremental bugfixes :

None for now.

Announce :

2010-05-22 multipath-tools-0.4.9 shortlog :

• Changes that may require your altering your config file :
  • rename hp_sw hwhandler
  • directio is now the default checker (async)
  • deprecated prio_callout keyword: now use prio/prio_args
  • move bindings file location to /etc
  • add ‘max_fds’ keyword
  • add ‘verbosity’ keyword
  • add ‘queue_without_daemon’ keyword
  • add ‘mode’, ‘uid’ and ‘gid’ keywords
  • add ‘fast_io_fail’ and ‘dev_loss_tmo’ keywords
  • add ‘checker’ keyword as alias to ‘path_checker’
• Features
  • make kpartx deal with more than 256 minor numbers
  • fail/reinstate CLI commands disable/enable path checker
  • support multipath-capable cciss hardware, add cciss_tur checker
  • ‘show config’ output usable as a config file replacement
  • create read-only multipath if rw try failed
  • care about offlined paths
  • support resizing of multipath maps
  • kpartx removes its loop devices
  • support other load-balancing policies
  • add datacore prioritizer
  • add ‘-r’ multipath arg to force maps reload
  • add ‘show paths format’ cli command
  • add ‘show maps format’ cli command
  • add ‘show status’ cli command
  • add ‘show wildcards’ cli command
  • add ‘quit’ cli command
  • add ‘enablequeueing’ and ‘disablequeueing’ cli commands
• Fixes
  • leaks plugged (virtualiron, suse, redhat work)
  • honour ALUA preference indicator
• Developers changes :
  • no more prioritizer callouts. replaced by mem-pinned .so to avoid having to cache the callouts.
  • move checkers to mem-pinned .so too
  • allow arguments passing to prioritizers
• Contributors :
  • Alex Zeffertt < ...@eu.citrix.com>
  • Andrey Panin < ...@pazke.donpac.ru>
  • Babu Moger < ...@lsi.com>
  • Benjamin Marzinski < ...@redhat.com>
  • Brian King < ...@linux.vnet.ibm.com>
  • Bryn M.Reeves < ...@redhat.com>
  • Chandra Seetharaman < ...@us.ibm.com>
  • Charlie Brady < ...@budge.apana.org.au>
  • Chauhan, Vijay < ...@lsi.com>
  • Christophe Varoqui < ...@opensvc.com>
  • Colin Watson < ...@canonical.com>
  • Dave Wysochanski < ...@redhat.com>
  • Guido Guenther < ...@sigxcpu.org>
  • Guido Günther < ...@sigxcpu.org>
  • Hannes Reinecke < ...@suse.de>
  • Jim Lester < ...@compellent.com>
  • Kiyoshi Ueda < ...@ct.jp.nec.com>
  • Konrad Rzeszutek < ...@virtualiron.com>
  • Martin Petermann < ...@linux.vnet.ibm.com>
  • Matthew Kent < ...@bravenet.com>
  • Mike Anderson < ...@linux.vnet.ibm.com>
  • Mike Snitzer < ...@redhat.com>
  • Moger, Babu < ...@lsi.com>
  • Nikanth Karthikesan < ...@suse.de>
  • Ritesh Raj Sarraf < ...@researchut.com>
  • Rumko < ...@gmail.com>
  • Stefan Bader < ...@de.ibm.com>
  • Stefan Haberland < ...@de.ibm.com>
  • Stefan Weinhuber < ...@de.ibm.com>
  • Yanqing Liu < ...@dell.com>

Dependencies :

Linux kernel

• 2.6.10-rc*-udm2 or later
• 2.6.11-mm* or later
• 2.6.12-rc1 or later

udev 050+
libdevmapper 1.2.38+

Known issues :

• Update your config file : selector = ’round-robin 0′ (since 0.3.9)
• If you relied on the ‘-D’ multipath command flag, please adapt (since 0.4.0).
• The kernel feature ‘queue_if_no_path’ is known to have bugs (up to 2.6.10rc?-udm2).
• The EMC checker has a known bug, fixed in the next release (up to 0.4.1).
• The tools exits if /sys/fc_transport/target$h:$b:$t does not exists : not fair, fixed in next release (0.4.1 only).
• failback doesn’t work (up to 0.4.5 included)
• make rpm doesn’t work (0.4.5 only)

Previous releases :

repository

Change logs :

full pre-0.4.5 ChangeLog
0.4.5+ changes are tracked through the git repository : here

2007-08-02 multipath-tools-0.4.8 shortlog :

• Changes that may require your altering your config file :
  • seed cciss multipathing support for recent MSA hardware : warning, the cciss blacklist is not hardcoded anymore. Proliant owners should add it to your config file if you don’t want surprises.
  • pp_sgi renamed to pp_rdac : no behaviour change otherwise
  • Add ‘^dcssblk[0-9]*’ to default blacklist
  • Directio is now the default checker
  • Move id callouts to standardized /lib/udev
  • Adopt Suse udev rules
  • Add path group timeout handling (pg_timeout keyword)
  • Add blacklist exceptions
  • Almost every vendor updated the internal defaults for their hardware (‘show config’ cli command is your friend)
  • We support matching by SCSI revision now, in addition to Vendor and Product. No rev specified means all rev matches.
  • Blacklist entries and other strings in the config file are true regular expressions, not shell expansion syntax
• Features
  • prio: add a prioritizer for HP storageworks arrays
  • prio: add a prioritizer for HDS modular arrays
  • checkers: asynchronous checker framework. Directio is the first and only user. Means no more checking loop blocking (while holding lock the cli tries to acquire for example).
  • checkers: EMC checker support for ALUA EMC arrays
  • checkers: add RDAC path checker
  • lib: pick up existing alias (if any) from current dm config
  • cli: add syntax auto-completion
  • cli: new command, show blacklist
  • doc: More man pages
  • kpartx: handling for SUN partition tables
  • kpartx: c-slice handling for BSD partition tables
  • kpartx: handling for extended partitions
  • kpartx: accept /dev/dm-* as arg
• Fixes
  • checkers: add a timeout to SG_IO ioctls
  • checkers: read buffer size bumped to 4096 bytes (Infiniband)
  • checkers: handling CLARiiON I/O to inactive snapshot logical units
  • lib: support newer kernels sysfs layout (remove libsysfs dependency)
  • lib: we keep stale paths in multipaths in case they get back online, but multipathd had trouble dealing with device name change in this situation : fixed
  • lib: listen events from udev socket instead of netlink : proper serialization allows to remove wait_for_devnode_appearance() hacks
  • lib: fix user_friendly_names race leading to a mpathX being served multiple times
  • lib: fix bug limiting to <8 paths luns
  • lib: don’t discard paths with large uuid
  • lib: don’t segfault when no config file
  • kpartx: large file support
  • kpartx: fix partition calculations of DASD partitions
  • prio: fix ALUA for minor >256
• Developers changes :
  • checkers: Checkers attached to different paths of a same multipath can share information through a context pointer in ‘struct multipath’
  • lib: use DM uuid ‘mpath-‘ prefix
  • kpartx: use DM uuid ‘part%d-‘ prefix

2006-03-13 multipath-tools-0.4.7 shortlog :

• multipathd empowering
  • DM driving directly from the daemon, without resorting to multipath(8)
  • udev rules deprecation, as events are acted upon directly through uevent in the daemon. The kpartx rule remains though
• multipathd CLI commands
  • enh : the CLI parser now accept unambiguous shortcuts, like ‘sho topo’ for ‘show topology’
  • new : ‘show config’ drops a config file as seen by the live daemon
  • new : ‘show maps stats’ drops some statistics about multipaths events
  • new : ‘show topology’, mimics the ‘multipath -ll’ output
  • new : ‘show map $map topology’, mimics the ‘multipath -ll $map’ output
  • enh : ‘reconfigure’ correctness issues fixed, scope extended
  • enh : ‘add/del map’ now apply to the DM live configuration too (!!caution, maps are really removed!!)
  • rem : ‘dump pathvec’, deprecated
• prioritizers
  • new : netapp prioritizer
  • new : tpc prioritizer (SGI, …)
• netlink uevent robustness
  • bigger receive buffer
  • uevent queueing and async dequeueing
• configuration
  • rr_min_io can be put in ‘device’ and ‘multipath’ config blocks
  • internal defaults are now exhaustive
  • tweak defaults for HP, SGI, IBM, EMC, …
• multipaths renaming through DM renames rather than remove/add cycles
• logging
  • ‘multipathd -d’ now prints the date
  • overall output beautifying
• drop the ‘path cache’ framework
• kpartx
  • fixes to dos partition handler
  • new mac partition handler
• make the tools work with DASD
• blacklist
  • add per-device product-string blacklist
  • add a device blacklist
  • add a wwid blacklist
  • deprecate the ‘devnode_blacklist’ keyword ub favor of ‘blacklist’
• adapt to libsysfs2 api, without breaking compat with libsysfs1
• checkers
  • API rewrite
  • reduce allocation on the directio checking code path

2005-11-11 multipath-tools-0.4.6 shortlog :

• fixes
• add/del cli commands accept map names as param
• new add ‘reinstate/fail’ cli commands
• new add ‘suspend/resume’ cli commands
• extended information display in ‘show map/paths’ cli commands
• fix thread reaping logic
• user friendly map names (mpath[0..n]) without alias defines
• option to disable io queueing if no valid path after a delay
• vendor/product as regexp in config file
• set devmap uuid as multipath wwid
• move hotplug logic to udev’s rules.d/
• configlets now adds up or replace the hardcoded ones
• ALUA prioritizer update
• option to use priorities as weights in the round-robin scheduler
• add the directio checker

2005-09-02 multipath-tools-0.4.5 shortlog :

• multipathd keeps Device Mapper path status in sync with path checker status : proactive fail_path and reinstate_path
• proactive path group re-enable, as soon as one path goes up
• multipathd is now fully event driven :
  • NetLink uevents for kernels/distro that enables the feature
  • Hotplug
  • Unix socket messages
• a Command Line Interface to drive and inspect the daemon
• remove the multipath(8) cache file logic in favour of a multipathd<->multipath unix socket request/reply design
• split multipath(8) listing option into
  • short-list (-l) : don’t fetch wwid, path checker status, priorities … fast
  • detailed-list (-ll) : refetch all info
• the daemon asynchronous logger is now solid and avoid sending critical messages
• daemon CLI command to reload the config file
• path checking interval gets longer when the path is reliably up, resets to short as soon as a problem occur
• daemon implements 3 path group failback methods :
  • manual
  • immediate : failback as soon as an (enabled && !active) PG gets the highest priority
  • defered : failback to the highest priority (enabled && !active) PG n seconds after the last PG priority order change
• remove over-complicated and thread-confusing daemon initial clone() w/ private namespace
• prioritizers official prefix is now mpath_prio_
• multipath(8) displays PG priorities when available
• new hp_sw checker. It’s a tri-state UP/DOWN/GHOST
• new directio checker. Useful with DASD devices. May suplant readsector0 in the long run ?
• stricter default blacklist regexps
• new ‘-f’ multipath(8) flag to selectively suppress a multipath map, and its device-mapped partitions
• alua prioritizer update, should work on x86
• support for >2TB multipaths
• claimed device detection : no more warning/error messages with paths pinned by mounted FS
• option to use priorities as weights in the round-robin scheduler : for people who can’t wait for a qlen-based scheduler

2005-04-24 multipath-tools-0.4.4 shortlog :

• 2 new path prioritizers : pp_alua and pp_emc
• devmap_name can now filter by target_type (-t flag).
• For example, no output if not ‘multipath’ type.
• the daemon sets /proc/self/oom_adj to -17, hence is
• protected from the oom killer. Watch out for leaks.
• libdevmapper 1.01.01 or newer is now recquired
• blacklist synthax is now regex based. Update your config files. The packaged templates are up to date.
• you can now set wwid in the blacklist
• multipathd gained a ‘-v’ flag to tune verbosity
• daemon logging is now staged and asynchronous to avoid syslogd possible hangs
• droped local klibc, libsysfs and libdevmapper
• multipath caches path info. Cache expire in 5sec.
• ‘multipath -l’ accepts a devname or dev_t filter