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linux/drivers/md
Keld Simonsen 8ed3a19563 md: don't attempt read-balancing for raid10 'far' layouts
This patch changes the disk to be read for layout "far > 1" to always be the
disk with the lowest block address.

Thus the chunks to be read will always be (for a fully functioning array) from
the first band of stripes, and the raid will then work as a raid0 consisting
of the first band of stripes.

Some advantages:

The fastest part which is the outer sectors of the disks involved will be
used.  The outer blocks of a disk may be as much as 100 % faster than the
inner blocks.

Average seek time will be smaller, as seeks will always be confined to the
first part of the disks.

Mixed disks with different performance characteristics will work better, as
they will work as raid0, the sequential read rate will be number of disks
involved times the IO rate of the slowest disk.

If a disk is malfunctioning, the first disk which is working, and has the
lowest block address for the logical block will be used.

Signed-off-by: Keld Simonsen <keld@dkuug.dk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
..
raid6test md: raid6: clean up the style of raid6test/test.c 2008-02-06 10:41:18 -08:00
.gitignore
bitmap.c md: reduce CPU wastage on idle md array with a write-intent bitmap 2008-03-04 16:35:17 -08:00
dm-bio-list.h dm: bio_list macro renaming 2007-10-20 02:01:11 +01:00
dm-bio-record.h
dm-crypt.c dm crypt: use async crypto 2008-02-08 02:11:14 +00:00
dm-delay.c dm: bio_list macro renaming 2007-10-20 02:01:11 +01:00
dm-emc.c dm mpath: emc fix an error message 2007-10-20 02:01:12 +01:00
dm-exception-store.c dm snapshot: use uninitialized_var 2008-02-08 02:10:11 +00:00
dm-hw-handler.c dm: use kzalloc 2007-10-20 02:01:07 +01:00
dm-hw-handler.h dm mpath: add retry pg init 2007-10-20 02:01:18 +01:00
dm-io.c Drop 'size' argument from bio_endio and bi_end_io 2007-10-10 09:25:57 +02:00
dm-io.h dm io: remove old interface 2007-05-09 12:30:47 -07:00
dm-ioctl.c dm ioctl: use uninitialized_var 2008-02-08 02:10:16 +00:00
dm-linear.c
dm-log.c dm log: auto load modules 2008-02-08 02:11:19 +00:00
dm-log.h dm log: split suspend 2007-10-20 02:01:21 +01:00
dm-mpath-hp-sw.c dm mpath: hp retry if not ready 2007-10-20 02:01:20 +01:00
dm-mpath-rdac.c dm mpath: rdac fix init race 2007-10-20 02:00:57 +01:00
dm-mpath.c dm mpath: add missing static 2008-02-08 02:10:35 +00:00
dm-mpath.h
dm-path-selector.c dm: use kzalloc 2007-10-20 02:01:07 +01:00
dm-path-selector.h
dm-raid1.c dm-raid1.c: fix NULL dereferences 2008-02-19 15:52:27 -08:00
dm-round-robin.c dm: remove duplicate module name from error msgs 2007-07-12 15:01:08 -07:00
dm-snap.c dm snapshot: combine consecutive exceptions in memory 2008-02-08 02:11:27 +00:00
dm-snap.h dm snapshot: combine consecutive exceptions in memory 2008-02-08 02:11:27 +00:00
dm-stripe.c dm: stripe enhanced status return 2008-02-08 02:11:24 +00:00
dm-table.c Introduce path_put() 2008-02-14 21:13:33 -08:00
dm-target.c dm: use kzalloc 2007-10-20 02:01:07 +01:00
dm-uevent.c dm: uevent generate events 2007-10-20 02:01:26 +01:00
dm-uevent.h dm: uevent generate events 2007-10-20 02:01:26 +01:00
dm-zero.c Drop 'size' argument from bio_endio and bi_end_io 2007-10-10 09:25:57 +02:00
dm.c dm: move deferred bio flushing to workqueue 2008-02-08 02:11:17 +00:00
dm.h dm: trigger change uevent on rename 2007-12-20 17:32:11 +00:00
faulty.c md: change ITERATE_RDEV to rdev_for_each 2008-02-06 10:41:19 -08:00
Kconfig dm: targets no longer experimental 2008-02-08 02:10:32 +00:00
kcopyd.c kcopyd use mutex instead of semaphore 2007-10-20 02:01:08 +01:00
kcopyd.h
linear.c md: change ITERATE_RDEV to rdev_for_each 2008-02-06 10:41:19 -08:00
Makefile dm: add uevent to core 2007-10-20 02:01:24 +01:00
md.c md: lock access to rdev attributes properly 2008-03-04 16:35:18 -08:00
mktables.c md: raid6: Fix mktable.c 2008-02-06 10:41:18 -08:00
multipath.c md: change ITERATE_RDEV to rdev_for_each 2008-02-06 10:41:19 -08:00
raid0.c md: change ITERATE_RDEV to rdev_for_each 2008-02-06 10:41:19 -08:00
raid1.c md: fix deadlock in md/raid1 and md/raid10 when handling a read error 2008-03-04 16:35:17 -08:00
raid5.c md: fix an occasional deadlock in raid5 2008-02-06 10:41:19 -08:00
raid6.h
raid6algos.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6altivec.uc
raid6int.uc
raid6mmx.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6recov.c
raid6sse1.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6sse2.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6x86.h x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid10.c md: don't attempt read-balancing for raid10 'far' layouts 2008-03-04 16:35:18 -08:00
unroll.pl