On Jul 19, 2011, at 11:31 AM, Thomas D. Dean wrote: >> ar0 is the RAID-0 volume. However, I would advise against using Intel's >> Matrix pseudo-RAID for a boot volume, > > Why? > > I searched and did not find a reason to not use it. Just a few > "recommend against it" without reasons.
There's a set of FreeBSD PR's mentioned at the bottom of: http://en.wikipedia.org/wiki/Intel_Matrix_RAID If you lost a disk even when using mirroring, the system would likely panic and experience data corruption. If you had a disk drop off and reattach, it would possibly be probed as a different RAID volume. There have been some recent fixes to GEOM RAID mentioned below which are relevant. Regards, -- -Chuck Begin forwarded message: > From: Jeremy Chadwick <free...@jdc.parodius.com> > Date: June 17, 2011 5:51:24 PM PDT > To: freebsd-sta...@freebsd.org > Cc: freebsd...@freebsd.org > Subject: MFC: graid(8) (RAID GEOM) support > > Sorry for the cross-post, but I thought both lists would want to know > about this. > > Looks like mav@ just committed this ~17 hours ago: > http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/geom/raid/g_raid.c > > Those who have historically wanted to use Intel MatrixRAID (now called > Intel RST (Rapid Storage Technology)), but haven't due to the severe > issues/risks with ataraid(4), will probably be very interested in > this commit. I know I am! > > I plan on stress-testing the Intel support on a 2-disk system with > RAID-1 enabled, and will document my experiences, procedures, etc... > > Thanks, mav@ and imp@ ! > > I'll be sending another mail momentarily asking about USB memory stick > image building, since to accomplish the above, I want to do a > "bare-bones" install on our test system (e.g. enable Intel RAID, set up > 2 disks in a RAID-1 mirror, boot a USB memory stick that contains this > latest RELENG_8 build, and do sysinstall, etc.. the normal way). > > > ===================================================================== > MFC r219974, r220209, r220210, r220790: > Add new RAID GEOM class, that is going to replace ataraid(4) in supporting > various BIOS-based software RAIDs. Unlike ataraid(4) this implementation > does not depend on legacy ata(4) subsystem and can be used with any disk > drivers, including new CAM-based ones (ahci(4), siis(4), mvs(4), ata(4) > with `options ATA_CAM`). To make code more readable and extensible, this > implementation follows modular design, including core part and two sets > of modules, implementing support for different metadata formats and RAID > levels. > > Support for such popular metadata formats is now implemented: > Intel, JMicron, NVIDIA, Promise (also used by AMD/ATI) and SiliconImage. > > Such RAID levels are now supported: > RAID0, RAID1, RAID1E, RAID10, SINGLE, CONCAT. > > For all of these RAID levels and metadata formats this class supports > full cycle of volume operations: reading, writing, creation, deletion, > disk removal and insertion, rebuilding, dirty shutdown detection > and resynchronization, bad sector recovery, faulty disks tracking, > hot-spare disks. For Intel and Promise formats there is support multiple > volumes per disk set. > > Look graid(8) manual page for additional details. > > Co-authored by: imp > Sponsored by: Cisco Systems, Inc. and iXsystems, Inc. > ===================================================================== > > -- > | Jeremy Chadwick jdc at parodius.com | > | Parodius Networking http://www.parodius.com/ | > | UNIX Systems Administrator Mountain View, CA, US | > | Making life hard for others since 1977. PGP 4BD6C0CB | > > _______________________________________________ > freebsd-sta...@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
