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Author SHA1 Message Date
sos
f820cdfe29 This is the much rumoured ATA mkIII update that I've been working on.
o       ATA is now fully newbus'd and split into modules.
        This means that on a modern system you just load "atapci and ata"
        to get the base support, and then one or more of the device
        subdrivers "atadisk atapicd atapifd atapist ataraid".
        All can be loaded/unloaded anytime, but for obvious reasons you
        dont want to unload atadisk when you have mounted filesystems.

o       The device identify part of the probe has been rewritten to fix
        the problems with odd devices the old had, and to try to remove
        so of the long delays some HW could provoke. Also probing is done
	without the need for interrupts, making earlier probing possible.

o       SATA devices can be hot inserted/removed and devices will be created/
        removed in /dev accordingly.
	NOTE: only supported on controllers that has this feature:
	Promise and Silicon Image for now.
	On other controllers the usual atacontrol detach/attach dance is
	still needed.

o	Support for "atomic" composite ATA requests used for RAID.

o       ATA RAID support has been rewritten and and now supports these
        metadata formats:
                 "Adaptec HostRAID"
                 "Highpoint V2 RocketRAID"
                 "Highpoint V3 RocketRAID"
                 "Intel MatrixRAID"
                 "Integrated Technology Express"
                 "LSILogic V2 MegaRAID"
                 "LSILogic V3 MegaRAID"
                 "Promise FastTrak"
                 "Silicon Image Medley"
		 "FreeBSD PseudoRAID"

o       Update the ioctl API to match new RAID levels etc.

o       Update atacontrol to know about the new RAID levels etc
        NOTE: you need to recompile atacontrol with the new sys/ata.h,
        make world will take care of that.
	NOTE2: that rebuild is done differently from the old system as
	the rebuild is now done piggybacked on read requests to the
	array, so atacontrol simply starts a background "dd" to rebuild
	the array.

o       The reinit code has been worked over to be much more robust.

o       The timeout code has been overhauled for races.

o	Support of new chipsets.

o       Lots of fixes for bugs found while doing the modulerization and
        reviewing the old code.

Missing or changed features from current ATA:

o       atapi-cd no longer has support for ATAPI changers. Todays its
        much cheaper and alot faster to copy those CD images to disk
        and serve them from there. Besides they dont seem to be made
        anymore, maybe for that exact reason.

o       ATA RAID can only read metadata from all the above metadata formats,
	not write all of them (Promise and Highpoint V2 so far). This means
	that arrays can be picked up from the BIOS, but they cannot be
	created from FreeBSD. There is more to it than just the missing
	write metadata support, those formats are not unique to a given
	controller like Promise and Highpoint formats, instead they exist
	for several types, and even worse, some controllers can have
	different formats and its impossible to tell which one.
	The outcome is that we cannot reliably create the metadata of those
	formats and be sure the controller BIOS will understand it.
	However write support is needed to update/fail/rebuild the arrays
	properly so it sits fairly high on the TODO list.

o       So far atapicam is not supported with these changes. When/if this
	will change is up to the maintainer of atapi-cam so go there for
	questions.

HW donated by:  Webveveriet AS
HW donated by:  Frode Nordahl
HW donated by:  Yahoo!
HW donated by:  Sentex
Patience by:	Vife and my boys (and even the cats)
2005-03-30 12:03:40 +00:00