6.0 on Dell 1850 with PERC4e/DC RAID?

[Jung-uk Kim]

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. :-(

> Doug A.
>
> PS. sorry for the null email before this.  Hit the wrong key.

No need to be sorry.  I made the same mistake again. ;-)

Thanks for the info,

Jung-uk Kim