mdadm hook or kernel bug ?

warm · 2012-09-21 16:00:17

I have server with software raid1 (md0 - root, md1 and md2 - data). I run pacman -Syu every 3 month. Yesterday I did this and got in fault. Kernel was not able to find md0 but md1 and md2 were found. I got fult shell but could not do anything there. There was kernel upgrade from 3.4.6 to 3.5.4. Then I booted from install media and did arch-chroot to mounted md0 (which was md127 by udev). I installed 3.4.6 back and it booted fine (!) but usbinput hook did not work with 3.4.6. I tried to upgrade kernel again to 3.5.4 with mdadm included to initramfs image. Again kernel did not find md0 but mdadm -E -s showed all 3 md-partitions.

I did not know what to do and I replaced mdadm hook to mdadm_udev and reinstalled kernels. After that kernel 3.5.4 was able to load correctly. 3.4.6 was too but usbinput hook did not work with it :-). Sever platfom has only USB for keyboard so I cannot use keyboard with 3.4.6 - usually I do everythin via ssh but this kernel upgrade made me to take the server from the server room and work with it from the keyboard and the monitor.

It was not a critical server, so nothing wrong with his omission was not. I have a few critical servers on Archlinux that I have to upgrade. They are most identical. So what should I do to avoid failure in time of upgrade ?

Should I replace mdadm hook to mdadm_udev everywhere on the servers ? Is it safely ?

What could be wrong with usbinput hook and 3.4.6 kernel ?

Of course I will keep working kernels before upgrade :-).

falconindy · 2012-09-21 21:50:17

I have little interest in supporting the mdadm hook. Assembly via udev is the preferred method here.

warm · 2012-09-24 01:51:43

I have tried to "makinitcpio ..." with 3.5.4 and with 3.4.6 kernels with all other softs up to date. Why mdadm hook works for 3.4.6 and does not work for 3.5.4 ?

Seems that only I get this trouble and no one else .

jdarnold · 2012-09-24 14:33:49

Oh, I'm running into this exact problem after a system upgrade after far too long. What does "Assembly via udev" mean?

warm · 2012-09-25 03:46:43

jdarnold wrote:

Oh, I'm running into this exact problem after a system upgrade after far too long. What does "Assembly via udev" mean?

This mean You (We) should use hook named "mdadm_udev" for making initram via mkinitcpio but not "mdadm". Check HOOKS in /etc/mkinitcpio.conf . My is

HOOKS="base udev autodetect pata scsi sata mdadm_udev usbinput filesystems"

jdarnold · 2012-09-25 13:21:44

thanks - that's what I did and it helped, although I then ran into another problem with the LVM partition. One step at a time...

Arch Linux

#1 2012-09-21 16:00:17

mdadm hook or kernel bug ?

#2 2012-09-21 21:50:17

Re: mdadm hook or kernel bug ?

#3 2012-09-24 01:51:43

Re: mdadm hook or kernel bug ?

#4 2012-09-24 14:33:49

Re: mdadm hook or kernel bug ?

#5 2012-09-25 03:46:43

Re: mdadm hook or kernel bug ?

#6 2012-09-25 13:21:44

Re: mdadm hook or kernel bug ?

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