2.6.14, 2.6.15 md mystery partially solved (was: 2.6.15: mdrun, udev
Last month, I posted about the a mystery: I could not boot into 2.6.15 when using RAID. As of yesterday I found that I couldn't boot into 2.6.14 any more, either -- right now I'm back on 2.6.12. At the time the theory was that udev and md were in some sort of race condition.
The lack of 2.6.14 boot motivated me to see if I could solve the 2.6.15 problem.
Part of the mystery is solved: someone -- I have to assume it was a prank -- renamed the md module the "md-mod" module. Therefore it never showed up in the boot image. My mind boggles at the thought of renaming the module without warning and without catching it during depmod. Oh, and another gotcha: "mdadm --auto" doesn't create the /dev/md directory; you have to do it yourself. A bit of missing documentation there. (Sorry
if I sound a bit bitter, but renaming the module retrospectively? It's
a major gotcha.)
Other problems, however, persist in 2.6.15: the standard script "mdrun" tries to create a /dev/md/0 even though I don't have an array by that name. I created a custom hook and custom script which uses /etc/mdamd.conf to create the correct devices. As a side benefit of these custom scripts, which use "mdadm --auto", I don't get the the create dozens of /dev/md* entries created by the standard "mdrun."
Unfortunately I get a kernel panic when I try to boot the 2.6.15 image, for unknown reasons; I can't even tell where the problem occurs just yet. But as sad as that may be, at least this "md" problem turns out not to be a udev problem.
I'd send the partial solution off to the Debian developers, but for the life of me I can't figure out who should get the solution.
So thanks to everyone who commented during the previous thread!
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Moshe Yudkowsky work: http://www.Disaggregate.com book: http://www.PebbleAndAvalanche.com ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid0944&bid$1720&dat1642 _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net [email protected] https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel
Re: 2.6.14, 2.6.15 md mystery partially solved (was: 2.6.15: mdrun,
If anyone is interested, the reason I couldn't boot 2.6.15 wasn't udev -- it was initramfs-tools. Several separate bugs!
* the md module wasn't being loaded because it'd been renamed to md-mod, and even when that was fixed md-mod wasn't being loaded because modprobe doesn't put out the insmod line we'd expect from the modprobe documentation.
* mdrun attempts to create an /dev/md/0. I gave up and replaced mdrun with "mkdir /dev/md; mdadm --scan --auto".
<http://bugs.debian.org/cgi-bin/bugreport.cgi?bug55580> for full details.
And I'm pleased to report that udev properly creates the symlinks from /dev/mdN to /dev/md/N -- mdrun's symlinking is not required.
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Moshe Yudkowsky work: http://www.Disaggregate.com book: http://www.PebbleAndAvalanche.com ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid0944&bid$1720&dat1642 _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net [email protected] https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel