Re: Breakage with raid in 2.6.11-rc1-mm1 [Regression in mm]

[Sander <sander@humilis.net>]

Randy.Dunlap wrote (ao):
> Reuben Farrelly wrote:
> >At 12:58 a.m. 15/01/2005, Andrew Morton wrote:
> >
> >>Reuben Farrelly <reuben-lkml@reub.net> wrote:
> >>>
> >>> Something seems to have broken with 2.6.11-rc1-mm1, which worked ok 
> >>with
> >>> 2.6.10-mm3.
> >>>
> >>> NET: Registered protocol family 17
> >>> Starting balanced_irq
> >>> BIOS EDD facility v0.16 2004-Jun-25, 2 devices found
> >>> md: Autodetecting RAID arrays.
> >>> md: autorun ...
> >>> md: ... autorun DONE.
> >>> VFS: Waiting 19sec for root device...

...

> >>> VFS: Waiting 1sec for root device...
> >>> VFS: Cannot open root device "md2" or unknown-block(0,0)
> >>> Please append a correct "root=" boot option
> >>> Kernel panic - not syncing: VFS: Unable to mount root fs on 
> >>unknown-block(0,0)
> >>>
> >>> The system is running 5 RAID-1 partitions, and md2 is the root as
> >>> per grub.conf.  Problem seems to be that raid autodetection finds
> >>> no raid partitions :(
> >>>
> >>> The two ST380013AS SATA drives are detected earlier in the boot, so 
> >>I don't
> >>> think that's the problem..
> >>
> >>hm, the only raidy thing we have in there is the below.  Maybe you could
> >>try reverting that?
> >>
> >>--- 25/drivers/md/raid5.c~raid5-overlapping-read-hack   2005-01-09 
> >>22:20:40.211246912 -0800
> >>+++ 25-akpm/drivers/md/raid5.c  2005-01-09 22:20:40.216246152 -0800

...

> >Ok the breakage occurred somewhere between 2.6.10-mm3 (works) and 
> >2.6.11-rc1 (doesn't work) ie wasn't introduced into the latest -mm 
> >patchset as I first thought.
> >
> >Are there any other patches that might be worth a try backing out?
> 
> Someone else reported that they had to back out this one:
> waiting-10s-before-mounting-root-filesystem.patch
> 
> Can you revert that one and let us know how it goes?

It Works For Me(tm). This is unpatched 2.6.11-rc1-mm1 (no patches
reverted too):

# uname -r
2.6.11-rc1-mm1
# cat /proc/mdstat 
Personalities : [raid0] [raid1] [raid5] [multipath] [raid10] 
Event: 2                   
md1 : active raid10 sdd2[3] sdc2[2] sdb2[1] sda2[0]
      70684416 blocks 128K chunks 2 near-copies [4/4] [UUUU]
      
md0 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0]
      500608 blocks [4/4] [UUUU]
      
unused devices: <none>
# mount
/dev/md1 on / type reiser3 (rw,sync,data=journal,barrier=flush)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/md0 on /boot type ext2 (ro)
tmpfs on /tmp type tmpfs (rw)


So the problem depends on something. This system is SCSI, and I don't
use modules. I'm happy to provide more info if that would be of any
help.

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