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Blµb

Member

Registered: 2008-02-10

Posts: 224

mdraid + intel + root filesystem = fail ( = read only)

I've recently added two 1TB disks into my workstation since the other disks seemed to be dying - (take up to 10 seconds to be recognized, and sometimes aren't recognized at all).
Since 1TB is a lot, I decided to use RAID1 (mirroring) for them. This worked fine at first, when I used mdadm to simply create a "normal" software raid.
But later I wanted the drive to be available to windoze as well, and for that it has to use the IMSM metadata. So now the drive works in windoze, the bios recognizes it too, and when I boot into the arch netinstall disc I can assemble the drives using:

mdadm -Ebs > /etc/mdadm.conf && mdadm -As

(However, using "mdassemble" alone segfaults)

But here's the problem: I also have my root filesystem on the raid system, and when I boot it there are multiple problems:

1) With the "default" mdadm hook in the initcpio, "mdassemble" segfaults.
2) When adapting the initcpio to use "mdadm -As" with my mdadm.conf file, the root filesystem stays read-only, and I cannot switch to read-write.
So /proc/mdstat shows "read-only" (in contrast to "auto-read-only" like when I first assemble them when booting the netinstall disc, after which I can mount and write to the partitions).
And if I try to "mdadm --readwrite" the device, I have to select a partition (/dev/md126p1 rather than /dev/md126), but remounting or mounting then just hangs.

Currently I'm using the device mapper (dmraid), which works, but lacks many features.

Here's my mdadm.conf

root@blubpc ~ # mdadm -Ebs
ARRAY metadata=imsm UUID=732dd857:ac92b6cb:1d77e056:6a8481ad
ARRAY /dev/md/Volume0 container=732dd857:ac92b6cb:1d77e056:6a8481ad member=0 UUID=1051eb62:705d3f71:3843daa9:fff677ae

I have mdadm-3.1.2-2 installed, and use a custom kernel config based on arch's kernel26 package (2.6.34) with raid built into the kernel (and the device-mapper as modules)
The current system is only a few days old, so it is up to date.

---

You know you're paranoid when you start thinking random letters while typing a password.
A good post about vim
Python has no multithreading.

cedricmc

Member

From: Madrid, Spain

Registered: 2011-11-20

Posts: 53

Re: mdraid + intel + root filesystem = fail ( = read only)

Hi there! I just found I have this same problem. Did you solve it?

https://bbs.archlinux.org/viewtopic.php?id=138889