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Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

md devices gone

I rebooted my computer today ,and my /dev/md126 and other similarly names devices aren't being listed. I can see the sda-sdf devices, but the md's for RAID1 are gone. Do I need to back down my kernel? I had a RAID1 of ext4 and two RAID1s on btrfs if that helps.

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: md devices gone

Anything in dmesg or your journal? Please paste the output of `pacman -Q linux && uname -r`.

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Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

Re: md devices gone

linux 4.2.3-1
4.2.3-1-ARCH

Looks like the package is the same as the kernel to me. I tried reinstalling the linux package to fix it anyways.

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: md devices gone

Can you manually assemble the arrays?

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Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

Re: md devices gone

If you can point me to the information on how, then sure. Up until now, Linux always just took care of that for me. I never had to do that.

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: md devices gone

Well, it depends. You haven't provided much information about your system and how the arrays fit in. Are they just data arrays, or is / on one of them? Can you currently boot? If not, chroot in and try and assemble the array(s) from the live medium.

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Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

Re: md devices gone

I can boot. sda works, these don't. They are just data arrays in RAID1 yes. When they're in fstab, they don't get seen, and it goes into emergency mode.

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: md devices gone

Check the status of the arrays:

cat /proc/mdstat

Reassemble, if necessary (adapt as per your setup):

mdadm --assemble /dev/md0 /dev/sd[bc]1

Note: I have no experience with BTRFS, you will need someone else to provide guidance there...

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Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

Re: md devices gone

I get a "No such file or directory" for /proc/mdstat .

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: md devices gone

And... did you try this trick?

Pr0Wolf29

Member

Registered: 2012-03-30

Posts: 25

Re: md devices gone

And... did you try this trick?

I got my /proc/mdstat now.

Personalities :
unused devices: <none>

Not sure where to go from here, however I will be looking at various results from that to see if I can find the solution.

Edit:
After some reading, I've found something that may help.

# mdadm --examine --scan
ARRAY metadata=imsm UUID=1788d98c:3fb71323:49d67284:18e02c1f
ARRAY /dev/md/RAID-3TB container=1788d98c:3fb71323:49d67284:18e02c1f member=0 UUID=e0417939:ada7d01d:344a433a:e9618ee3
ARRAY metadata=imsm UUID=b9e987c9:fb8fde70:fadb7ead:98fb232e
ARRAY /dev/md/RAID1TB container=b9e987c9:fb8fde70:fadb7ead:98fb232e member=0 UUID=bcb61ba6:d2bf73b0:39c1a6e2:3db54660
ARRAY metadata=imsm UUID=90ed2de3:4c44efb8:ec5df507:f2952fb8
ARRAY /dev/md/RAID-4TB container=90ed2de3:4c44efb8:ec5df507:f2952fb8 member=0 UUID=7db6c47a:e86ff98f:c776a0f0:ab2cceb5

Last edited by Pr0Wolf29 (2015-10-24 22:31:03)