6.0 on Dell 1850 with PERC4e/DC RAID?

[Mike Tancsa]

At 11:59 AM 13/01/2006, Doug Ambrisko wrote:
>|
>| 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 :-(


Interesting timing as I ran into this sort of situation on the 
weekend on a 3ware drive in RAID1. The card had complained for a week 
about read errors on drive 1. We thought we would wait until the 
weekend maintenance window to swap it out.  Sadly, before that 
window, drive zero totally died a horrible death.  We popped in a new 
drive on port zero, started the rebuild, and it crapped out saying 
there was a read error on drive 1.  However, there is a check box 
that says continue the build, even with errors on the source drive.

This setup seems to give you the best of both worlds.  We did a quick 
check of the resultant files compared to backups and only a couple 
were toasted. (The box is going to be retired in a month, so if there 
is other hidden fs corruption if it holds out for another 3 weeks we 
dont care too much). The correct approach would be to do a total 
restore of course, but this was good enough for us in this 
situation.  I guess the question is, is this RAID1 in a proper mirror 
given that there are hard errors on the drive on port 1 ?

         ---Mike