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Old 10-14-2018, 09:47 PM   #1
Gabcixy
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Unhappy mdadm md0 disappears from /dev after reboot


I've created a RAID1 array with mdadm. Everything gone fine, the array was created and md0 was formatted and mounted. It accepted folders and files without any problem. However when I rebooted the system, md0 was gone from /dev.
I had to recreate with
"mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1" and mount the created md0 and everything was fine again until the next reboot. The entry in /etc/mdadm.conf is "ARRAY /dev/md0 level=raid1 num-devices=2 metadata=1.2 name=localhost.localdomain:0 UUID=1196a5d6:e87b3d9a:0b9825f1:ce81585a
devices=/dev/sdb1,/dev/sdc1" and it is persistent.
The entry is in /etc/fstab is correct.
I tried to solve the problem by removing the array, clear the disks, recreate the array. It worked fine until the next reboot. Checked many websites, but no solution as yet.

mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1
mdadm: /dev/sdb1 appears to be part of a raid array:
level=raid1 devices=2 ctime=Sun Oct 14 18:36:37 2018
mdadm: Note: this array has metadata at the start and
may not be suitable as a boot device. If you plan to
store '/boot' on this device please ensure that
your boot-loader understands md/v1.x metadata, or use
--metadata=0.90
mdadm: /dev/sdc1 appears to be part of a raid array:
level=raid1 devices=2 ctime=Sun Oct 14 18:36:37 2018
Continue creating array? y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

Last edited by Gabcixy; 10-14-2018 at 09:48 PM.
 
Old 10-14-2018, 11:33 PM   #2
syg00
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You don't need to create the array again, merely assemble it. The initrd should do it for you - just rebuild the initrd after you have the array properly assembled, then try a reboot.
 
Old 10-15-2018, 01:18 AM   #3
Gabcixy
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Quote:
Originally Posted by syg00 View Post
You don't need to create the array again, merely assemble it. The initrd should do it for you - just rebuild the initrd after you have the array properly assembled, then try a reboot.
Thanks for your reply but I do not know how to do that
My linux is PcLinuxOs

Last edited by Gabcixy; 10-15-2018 at 01:23 AM.
 
Old 10-18-2018, 12:17 AM   #4
Gabcixy
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Unhappy

Quote:
Originally Posted by syg00 View Post
You don't need to create the array again, merely assemble it. The initrd should do it for you - just rebuild the initrd after you have the array properly assembled, then try a reboot.
Can you please point me how to rebuild the initrd?
Since I am quite new in this I do not know.
 
Old 10-18-2018, 12:46 AM   #5
syg00
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Sorry, I unsubscribed from this thread.

That is somewhat distro specific - a quick search found this thread on the pclos fora. It has the mkinitrd command about half way down. Note it needs the current kernel version level which "uname -r" should give you.
Should be straight-forward, but if you mess it up you may not be able to boot; make sure you have another kernel in the boot list just in case. This should fix itself when pclos ship the next kernel if you have the array active when you do that update - might be worth just waiting.
 
Old 10-21-2018, 02:44 AM   #6
Gabcixy
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I tried all sort of solution but nothing worked. md0 still not found when I reboot the computer. Any idea? I tried even copy md0 to md1 but couldn't. Every solution is highly appreciated.
 
Old 10-21-2018, 03:45 AM   #7
qrange
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check if its /dev/md127 now

https://serverfault.com/questions/49...nged-on-reboot

i had such problem
 
  


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