Date: Tue, 27 Feb 2007 04:01:58 +0000 (UTC) From: Matt Jacob <mjacob@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/etc/mtree BSD.include.dist src/sbin/geom/class Makefile src/sbin/geom/class/multipath Makefile geom_multipath.c src/sys/conf NOTES files src/sys/geom/multipath g_multipath.c g_multipath.h src/sys/modules/geom Makefile ... Message-ID: <200702270401.l1R41w5O085013@repoman.freebsd.org>
next in thread | raw e-mail | index | archive | help
mjacob 2007-02-27 04:01:58 UTC
FreeBSD src repository
Modified files:
etc/mtree BSD.include.dist
sbin/geom/class Makefile
sys/conf NOTES files
sys/modules/geom Makefile
Added files:
sbin/geom/class/multipath Makefile geom_multipath.c
sys/geom/multipath g_multipath.c g_multipath.h
sys/modules/geom/geom_multipath Makefile
Log:
First cut at GEOM based multipath. This is an active/passive{/passive...}
arrangement that has no intrinsic internal knowledge of whether devices
it is given are truly multipath devices. As such, this is a simplistic
approach, but still a useful one.
The basic approach is to (at present- this will change soon) use camcontrol
to find likely identical devices and and label the trailing sector of the
first one. This label contains both a full UUID and a name. The name is
what is presented in /dev/multipath, but the UUID is used as a true
distinguishor at g_taste time, thus making sure we don't have chaos
on a shared SAN where everyone names their data multipath as "Fred".
The first of N identical devices (and N *may* be 1!) becomes the active
path until a BIO request is failed with EIO or ENXIO. When this occurs,
the active disk is ripped away and the next in a list is picked to
(retry and) continue with.
During g_taste events new disks that meet the match criteria for existing
multipath geoms get added to the tail end of the list.
Thus, this active/passive setup actually does work for devices which
go away and come back, as do (now) mpt(4) and isp(4) SAN based disks.
There is still a lot to do to improve this- like about 5 of the 12
recommendations I've received about it, but it's been functional enough
for a while that it deserves a broader test base.
Reviewed by: pjd
Sponsored by: IronPort Systems
MFC: 2 months
Revision Changes Path
1.111 +2 -0 src/etc/mtree/BSD.include.dist
1.14 +1 -0 src/sbin/geom/class/Makefile
1.1 +10 -0 src/sbin/geom/class/multipath/Makefile (new)
1.1 +230 -0 src/sbin/geom/class/multipath/geom_multipath.c (new)
1.1411 +1 -0 src/sys/conf/NOTES
1.1180 +1 -0 src/sys/conf/files
1.1 +768 -0 src/sys/geom/multipath/g_multipath.c (new)
1.1 +99 -0 src/sys/geom/multipath/g_multipath.h (new)
1.19 +1 -0 src/sys/modules/geom/Makefile
1.1 +8 -0 src/sys/modules/geom/geom_multipath/Makefile (new)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200702270401.l1R41w5O085013>