6.0 on Dell 1850 with PERC4e/DC RAID?

[Doug Ambrisko]

Jung-uk Kim writes:
| On Friday 13 January 2006 11:59 am, Doug Ambrisko wrote:
| > Jung-uk Kim writes:
| > | On Thursday 12 January 2006 07:41 pm, Doug Ambrisko wrote:
| > | > Scott Mitchell writes:
| > | > | > I did find a program
| > | > | > posted to one of the freebsd lists called 'amrstat' that I
| > | > | > run nightly.  It produces this kind of output:
| > | > | >
| > | > | > Drive 0:    68.24 GB, RAID1
| > | > | > <writeback,no-read-ahead,no-adaptative- io> optimal
| > | > | >
| > | > | > If it says "degraded" it is time to fix a drive.   You just
| > | > | > fire up the lsi megaraid tools and find out which drive it
| > | > | > is.
| > | >
| > | > This is probably a faily good scheme.  Caveat is that you can
| > | > have a "optimal" RAID that is broken :-(
| > |
| > | That's lame.  Under what condition does it happen, do you know?
| >
| > Running RAID 10, a drive was swapped and the rebuild started on the
| > replacement drive.  The rebuild complained about the source drive
| > for the mirror rebuild having read errors that couldn't be
| > recovered. It continued on and finished re-creating the mirror. 
| > Then the RAID proceeeded onto a background init which they normal
| > did and started failing that and re-starting the background init
| > over and over again. The box changed the RAID from degraded to
| > optimal when the rebuild completed (with errors).  Do a dd of the
| > entire RAID logical device returned an error at the bad sector
| > since it couldn't recover that. The RAID controller reported an I/O
| > error and still left the RAID as optimal.
| >
| > We reported this and where told that's the way it is designed :-(
| > Probably the spec. is defined by whatever the RAID controller
| > happens to do versus what make sense :-(
| >
| > So far this has only happened once.  Changing firmware did not
| > help.
| 
| Similar thing happened to me once or twice (with RAID5) and I thought 
| it was just a broken controller.  If the culprit was design, it IS 
| really lame. :-(

I'd suggest whining to them.  To me "optimal" means "as far as I know
there are no problems with the RAID".  If enough customers whine they
might change their view!

Doug A.