freebsd-nq/sys/geom/multipath
Alexander Motin 0c883cef45 Major GEOM MULTIPATH class rewrite:
- Improved locking and destruction process to fix crashes.
 - Improved "automatic" configuration method to make it consistent and safe
by reading metadata back from all specified paths after writing to one.
 - Added provider size check to reduce chance of ordering conflict with
other GEOM classes.
 - Added "manual" configuration method without using on-disk metadata.
 - Added "add" and "remove" commands to allow manage paths manually.
 - Failed paths are no longer dropped from geom, but only marked as FAIL
and excluded from I/O operations.
 - Automatically restore failed paths when all others paths are marked
as failed, for example, because of device-caused (not transport) errors.
 - Added "fail" and "restore" commands to manually control FAIL flag.
 - geom is now destroyed on last path disconnection.
 - Added optional Active/Active mode support. Unlike Active/Passive
mode, load evenly distributed between all working paths. If supported by
the device, it allows to significantly improve performance, utilizing
bandwidth of all paths. It is controlled by -A option during creation.
Disabled by default now.
 - Improved `status` and `list` commands output.

Sponsored by:	iXsystems, inc.
MFC after:	1 month
2011-11-12 09:52:27 +00:00
..
g_multipath.c Major GEOM MULTIPATH class rewrite: 2011-11-12 09:52:27 +00:00
g_multipath.h Major GEOM MULTIPATH class rewrite: 2011-11-12 09:52:27 +00:00