LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices

Reply
 
Search this Thread
Old 08-15-2011, 06:28 AM   #1
Sereph
LQ Newbie
 
Registered: Aug 2011
Posts: 2

Rep: Reputation: Disabled
Unhappy Attempts to work around a mdadm bug/ mdadm cannot get exclusive access to /dev/md127


Greetings and salutations. First and foremost, assume I know absolutely nothing about linux. I've been a Windows user all my life, having been hooked while watching my father upgrade Windows 3.1.

I have worked with Windows 95, 98, 98SE, 2000, XP, Vista, Server 2008, and now Windows 7. Last night I took the plunge into insanity, purging my OS to start from scratch. My plan is a Windows 7 Professional installation dual-booting with Fedora 15.

*edit: Just realized I mentioned Windows in my post, and thus this post should have gone into General. My sincere apologies...

The first part of my plan was easy. I created a RAID 0 array in my BIOS, 3 drives. I created a NTFS partition on the array, leaving half the space unallocated, and installed Windows, knowing that GRUB would take over from the Windows boot-loader during my linux installation. All was well and good, then I installed Fedora 15 on the array's unallocated space, and after getting slightly confused, I worked my way through the installation. GRUB did exactly what I anticipated, defaulting to Fedora with the option of entering Windows. However, this is where everything went down the tube. Instead of taking me into Linux goodness where I could rest comfortably in the safety of a GUI, I got dumped into a Dracut debug prompt.

After feeling confused, and doing some searches, I muddled about, injecting random commands to get a feel for what I was dealing with. After booting from my USB drive, I discovered that my installation could not find my root. Further poking revealed that I was dealing with the following problem:

dracut: mdadm (IMSM): Unsupported attributes: 40000000
dracut: mdadm IMSM metadata load not allowed due to attribute incompatibility

Which apparently is a known problem...just my luck.
https://bugzilla.redhat.com/show_bug.cgi?id=729205

The solution given is as follows: "You would need to boot up a
live cd or rescue image, use mdadm -E to get the exact info for your array,then recreate the array with the exact same options as it currently uses but passing in the --assume-clean option, then reboot to your arrays with the trouble causing bit cleared."

Not really knowing what I was doing, and coming from an MS-DOS command line background, I managed to isolate my array details with the following: # mdadm --examine /dev/md0
After painstakingly writing down EVERYTHING, just in case, I then attempted to create a new array per the following:
# mdadm --create /dev/md0 --chunk=128 --level=0 --raid-devices=3 /dev/sda /dev/sda1 /dev/sda2 --assume-clean

This however lead to some message about the array being in use or some such nonsense. I'm assuming at this point that was due to the fact that when I booted from the USB, I had performed the following: # chroot /mnt/sysimage

So logically, if I can unmount or somehow stop the array, I can proceed with my workaround. However, # mdadm --stop /dev/md0 informs me thusly: mdadm: Cannot stop container /dev/md0: member md127 still active

So from there I tried # mdadm --stop /dev/md127, but that lead to a message stating that mdadm: Cannot get exclusive access to /dev/md127: possibly it is still in use.

So from here I'm stumped... I want to keep my hardware-based array for Windows' sake, but I also want to get this miserable workaround in order. It is a legitimate bug that I'm dealing with, but it would be nice if I could do something that does not involve waiting on a new mdadm release.

Any help or suggestions for my predicament would be appreciated. Thus far my first linux experience has been less than productive...

Last edited by Sereph; 08-15-2011 at 06:34 AM.
 
Old 08-16-2011, 03:21 AM   #2
Sereph
LQ Newbie
 
Registered: Aug 2011
Posts: 2

Original Poster
Rep: Reputation: Disabled
Just an update. I didn't manage to employ the workaround, so I scrapped Fedora and went with Ubuntu. It works, I'm happy.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
when i use 'mdadm -S /dev/md127', it produce kernel event with no stop wwyyxx26 Linux - Kernel 1 05-01-2011 05:26 PM
mdadm bug? zackboll Linux - Software 2 08-25-2010 06:46 PM
MDADM screws up the LVM partitions? Can't mount the LVMs after mdadm stopped alirezan1 Linux - Newbie 3 11-18-2008 04:42 PM
unable to load MDADM module BUT mdadm works?!?!?! alirezan1 Linux - Software 2 09-08-2008 07:58 PM
mdadm says "mdadm: /dev/md1 not identified in config file" when booting FC7 raffeD Linux - Server 1 08-11-2008 11:47 AM


All times are GMT -5. The time now is 01:42 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration