Gentoo Archives: gentoo-user

From: Mark Knecht <markknecht@×××××.com>
To: Gentoo User <gentoo-user@l.g.o>
Subject: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root
Date: Mon, 31 Dec 2012 17:33:02
Message-Id: CAK2H+eemy9qT5QcNwmJMGq-ohf8ahvisa=dFSxb9GxsqcQ=4gw@mail.gmail.com
1 Hi,
2 I don't think this is likely to be a Gentoo issue but I figured I'd
3 ask here first before going elsewhere. (LKML, linux-raid, elsewhere)
4 Additionally it's not a critical problem at all but rather something
5 I'd like to try and understand and then report if appropriate.
6
7 On my main i7-980x machine I've been wanting to move root away from
8 an old 3-disk 50GB RAID1 that I built first built the machine with to
9 a newer 150GB RAID6. Toward this end the machine has two complete
10 Gentoo builds on it:
11
12 c2stable ~ # cat /proc/mdstat
13 <SNIP>
14
15 md3 : active raid6 sdc3[1] sdd3[2] sdb3[0] sde3[3] sdf3[5]
16 157305168 blocks super 1.2 level 6, 16k chunk, algorithm 2 [5/5] [UUUUU]
17
18 md126 : active raid1 sdd5[2] sdc5[1] sdb5[0]
19 52436032 blocks [3/3] [UUU]
20
21 unused devices: <none>
22 c2stable ~ #
23
24 md126 is the older RAID1, md3 is the newer RAID6. The are both built
25 on parts of the 5 hard drives in the box.
26
27 The two builds are intended to be identical. Same packages installed,
28 same kernel with the only exception being the RAID6 uses an initramfs
29 built into it. A diff of the two kernel configs shows only that
30 difference:
31
32 c2stable ~ # diff /usr/src/linux/.config /mnt/newRAID6/usr/src/linux/.config
33 137c137,139
34 < CONFIG_INITRAMFS_SOURCE=""
35 ---
36 > CONFIG_INITRAMFS_SOURCE="/usr/src/initramfs.config"
37 > CONFIG_INITRAMFS_ROOT_UID=0
38 > CONFIG_INITRAMFS_ROOT_GID=0
39 142a145,146
40 > CONFIG_INITRAMFS_COMPRESSION_NONE=y
41 > # CONFIG_INITRAMFS_COMPRESSION_GZIP is not set
42 c2stable ~ #
43
44 In my grub.conf file I have three methods of booting the machine.
45 There are two methods of booting the RAID1 config, using the device
46 name and using the label. For the RAID6 I have only the label method:
47
48 (NOTE: Snipped out backup kernels just to clarify)
49
50 c2stable ~ # cat /boot/grub/grub.conf
51 default 0
52 timeout 15
53 splashimage=(hd0,0)/boot/grub/splash.xpm.gz
54
55 title RAID1 3.6.11-gentoo
56 root (hd0,0)
57 kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=/dev/md126
58
59 title RAID1 3.6.11-gentoo using LABEL
60 root (hd0,0)
61 kernel (hd0,0)/boot/bzImage-3.6.11-gentoo root=LABEL=RAID1root
62
63 title RAID6 3.6.11-gentoo using LABEL
64 root (hd0,0)
65 kernel (hd0,0)/boot/bzImage-RAID6-3.6.11-gentoo root=LABEL=RAID6root
66
67 c2stable ~ #
68
69 c2stable ~ # e2label /dev/md126
70 RAID1root
71 c2stable ~ # e2label /dev/md3
72 RAID6root
73 c2stable ~ #
74
75
76 The results are:
77
78 1) RAID1 using md126 boots fine
79 2) RAID1 using label of RAID1root fails
80 3) RAID6 using label of RAID6root boots fine
81
82 The failure is a kernel crash before the machine gets very far so
83 the only capture I might be able to try is with a camera and then post
84 that on line, but the screen is 80x25 and it's just a kernel crash so
85 there's very little data on the screen when the machine dies.
86
87 I've been Googling around for a couple of days but haven't found
88 anything very interesting. I figured I'd ask here first just to see
89 what ideas come up.
90
91 Thanks,
92 Mark

Replies

Subject Author
Re: [gentoo-user] boot failure using root=LABEL=RAID1root but not LABEL=RAID6root "J. Roeleveld" <joost@××××××××.org>