[CentOS] [SOLVED] Centos 5.5, not booting latest kernel but older one instead

[fred smith]

On Mon, Aug 30, 2010 at 09:13:07PM -0700, Gordon Messmer wrote:
> On 08/30/2010 07:24 PM, fred smith wrote:
> > Aug 30 22:09:08 fcshome kernel: md: created md1
> ...
> > Aug 30 22:09:08 fcshome kernel: md: kicking non-fresh sda2 from array!
> ...
> > Aug 30 22:09:08 fcshome kernel: md: created md0
> ...
> > Aug 30 22:09:08 fcshome kernel: md: kicking non-fresh sda1 from array!
> 
> Yep, your arrays are broken.  mdmonitor should have emailed you about 
> this.  Make sure that you receive and read mail to the root user.
> 
> /sbin/mdadm /dev/md1 --fail /dev/sda2 --remove /dev/sda2
> /sbin/mdadm /dev/md1 --add /dev/sda2
> 
> /sbin/mdadm /dev/md0 --fail /dev/sda1 --remove /dev/sda1
> /sbin/mdadm /dev/md0 --add /dev/sda1

Thanks to Gordon, Robert, and all the others who contributed to my
learning experience!

The problem was that /dev/sda had dropped out of the raid array, and that
sdb remained. while sdb remained, it is the one that was being updated
by yum updates, but sda is the one that grub was booting. hence the out-
of-sync files/kernels/etc.

following the instructions above has solved the problem, and the array
is now rebuilding.

I found some references online in several places (newegg commentson the
specific WD drive I have, as well as other places) to a drive "feature"
called LTER that allows setting a timeout for slow reads (?? maybe 
read errors??? I'd have to go back and re-read 'cause my memory is
gone), and the default setting lets it delay for very long periods,
causing the raid controller to think the drive has died and to drop
it from the array. Apparently Linux software raid is subject to the same
issue.

These online sources go on to mention that older versions of the specific
drive model can have this setting changed (with the WDTLER.exe utility),
but that WD, in its infinite wisdom, has removed that capability from 
"newer" drives. I tried the utility on my system and it reports "no
drives found" so mine, even though they're over a year old, must be of
the "newer" category. I may end up replacing them if they continue to
do this to me. After all, the purpose and intent in building a desktop
system with RAID-1 was redundancy, NOT HASSLE.

Thanks again to all who advised.

Fred
-- 
---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
                        The Lord is like a strong tower. 
             Those who do what is right can run to him for safety.
--------------------------- Proverbs 18:10 (niv) -----------------------------