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On Thu, Mar 24, 2011 at 3:38 PM, Lindsay Haisley <fmouse-gentoo@×××.com> wrote: |
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> On Thu, 2011-03-24 at 15:15 -0500, Paul Hartman wrote: |
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>> On Thu, Mar 24, 2011 at 1:16 PM, Lindsay Haisley <fmouse-gentoo@×××.com> wrote: |
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>> > The root of this problem is that on the old kernel, there are both |
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>> > a /dev/hda1 and a /dev/sda1. The former is a partition on an old PATA |
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>> > drive, while the latter is a proper component of md0, but when |
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>> > everything becomes /dev/sdNx, there's an obvious conflict and the RAID |
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>> > subsystem is getting confused and is obviously not seeing it's sda1. |
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>> |
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>> Possible alternative is to disable raid autodetection and define the |
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>> arrays by UUID in /etc/mdadm.conf so hopefully the device names become |
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>> irrelevant at that point. |
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> |
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> This is a good idea. I can turn off RAID autodetection in the kernel |
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> config and spec RAID1 instead, since the root fs isn't on a RAID array. |
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> |
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> I've found a number of references to putting UUIDs in ARRAY lines |
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> in /etc/mdadm.conf to define the UUID of an array, but none yet to using |
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> UUID specs in DEVICE lines, all of which I've found so far in the online |
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> literature use /dev/xxxx specs. Before I take this step I'm going to |
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> find a more kernel-specific list and ask if this would be appropriate. |
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> I've tripped on RAID array errors before at the expense of days of work |
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> to reconstitute systems and their data. I want to make sure this is |
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> kosher before I go there. |
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|
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I was actually referring to the ARRAY lines and the array UUIDs. In |
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fact I don't even have a DEVICE line, man mdadm.conf says: |
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If no DEVICE line is present, then "DEVICE partitions containers" is assumed. |
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|
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My mdadm.conf only contains 2 ARRAY lines, for my 2 raid arrays. I |
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also specify the metadata version, I assume you're using superblock |
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0.90 since you've been using autodetect and autodetect isn't supported |
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for newer versions. |
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|
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So, mdadm scans all partitions (doesn't matter what they are named) |
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looking for superblocks containing the UUID of the arrays I specified. |
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Anything that doesn't match gets ignored for this purpose. |
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|
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The mdadm manpage has this example command: |
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|
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mdadm --examine --brief --scan --config=partitions |
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Create a list of devices by reading /proc/partitions, scan these for |
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RAID superblocks, and printout a brief listing of all that were |
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found. |
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|
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Hopefully you can find your array UUIDs with that command (and if it |
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finds them, that's a good sign for it's ability to assemble the arrays |
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once the config file is made) |
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|
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Good luck :) |