Help, my RAID won't start

Kevin O'Gorman kogorman at gmail.com
Tue Apr 4 15:56:13 UTC 2017 

SUCCESS.  Sort of.  It raises another question.

On reboot, I had /raid3.  But it is mounted on /dev/md127.  It appears the
system is ignoring the device in my mdadm.conf entry.  Here it is again:
ARRAY /dev/md3 metadata=1.2 name=camelot-x:3
UUID=07c3d55f:2c9b1534:6b0d5b78:dd9856ed
And here's the output of mdadm --detail --scan
ARRAY /dev/md/camelot-x:3 metadata=1.2 name=camelot-x:3
UUID=07c3d55f:2c9b1534:6b0d5b78:dd9856ed

And indeed there is a /dev/camelot-x:3

On Tue, Apr 4, 2017 at 8:48 AM, Kevin O'Gorman <kogorman at gmail.com> wrote:

>
>
> On Tue, Apr 4, 2017 at 8:18 AM, Kevin O'Gorman <kogorman at gmail.com> wrote:
>
>>
>>
>> On Tue, Apr 4, 2017 at 6:50 AM, Rashkae <ubuntu at tigershaunt.com> wrote:
>>
>>> On 17-04-04 12:17 AM, Kevin O'Gorman wrote:
>>>
>>>> I've been fooling with this for a while.  Some things are fixed, but the
>>>> darned thing still isn't right.
>>>>
>>>>
>>> It looks like you've partitioned your RAID device itself.  I'm not too
>>> sure how that's supposed to look, as I've never set them up that way.
>>> (I partition the physical devices, as you've done, then create a raid
>>> array, and create my FS directly on that array.)
>>>
>>> That's not to say what you have here is wrong, just that I'm not sure
>>> how to interpret the blkid output.
>>>
>>> But actually fixing your current situation is probably going to be
>>> simple.. *Don't* use device names in your fstab.. put in the UUID
>>>
>>> Example:
>>>
>>>
>>> UUID=a6470f33-4709-4c96-8cf4-2fc0a4c2cdf9 /raid3        ext4
>>>  defaults  0    2
>>>
>>> (Note the removal of nofail, and changing the last field to 2)
>>>
>>>
>>> You might also want to update your mdadm.conf
>>>
>>> Check the device name of your running array with cat /proc/mdstat
>>>
>>> Assuming it's the same as you have in the original message, md127
>>>
>>> mdadm --detail --scan /dev/md127
>>>
>>> Use the output of that command to replace the ARRAY /dev/md3
>>> metadata=1.2 name=camelot-x:3
>>> UUID=07c3d55f:2c9b1534:6b0d5b78:dd9856ed
>>>
>>
>> Thanks...
>>
>> I tried your entry in my /etc/fstab, and "mount /raid3", and while the
>> mount finished without reporting an error, there
>> was no filesystem on /raid3, and /var/log/syslog now ends with
>>
>> Apr  4 07:37:14 camelot-x wpa_supplicant[1553]: wlp7s0: WPA: Group
>> rekeying completed with b4:75:0e:fc:84:9a [GTK=TKIP]
>> Apr  4 07:46:46 camelot-x kernel: [38933.017667] EXT4-fs (md127p1):
>> mounted filesystem with ordered data mode. Opts: (null)
>> Apr  4 07:46:46 camelot-x systemd[1]: raid3.mount: Unit is bound to
>> inactive unit dev-md3p1.device. Stopping, too.
>> Apr  4 07:46:46 camelot-x systemd[1]: Unmounting /raid3...
>> Apr  4 07:46:46 camelot-x systemd[1]: Unmounted /raid3.
>>
>> All of this in spite of /proc/mdstat reporting an active RAID array....
>>
>> So I tried putting the filesystem directly on the RAID, as you suggested,
>> with
>> dd if=/dev/zero of=/dev/md127 bs=1024 count=1024
>> mdadm --stop /dev/md127
>> mdadm --remove /dev/md127
>> mdadm -A --scan /dev/md3
>> mkfs.ext4 -m .01 -b 4096 -E stride=32,stripe-width=64 /dev/md3
>>
>> And was still unable to mount /raid3, but now I can see the syslog is
>> complaining that /raid3 is still bound to the
>> non-existent partition /dev/md3p1.  So I mounted it on a new directory
>> /raid3x.  It seems okay, in that it has
>> lost+found and lots of space.  But it did so last time too.
>>
>> I'm going to stick with my /etc/fstab entry for now, because I want to be
>> sure I get a warning if it ever gets assembled
>> as anything except /dev/md3.  The mdadm.conf entry is still correct, so
>> I'm going to reboot to make sure everything gets
>> assembled correctly.  Back in a few.....
>>
>> --
>> Kevin O'Gorman
>> #define QUESTION ((bb) || (!bb))   /* Shakespeare */
>>
>> Please consider the environment before printing this email.
>>
> That did NOT work.  Not exactly, anyway.
>
> There was nothing mounted on /raid3 after the reboot, and there was a
> /dev/md127 that I cannot get rid of in spite of multiple tries at
> mdadm --stop /dev/md127
> mdadm --remove /dev/md127
> But it did not show up in /proc/mdstat any more so I reassembled it
> mdadm -A --scan /dev/md3
> And it was not only assembled but mounted too.
>
> lsblk shows
> sdd       8:48   0   3.7T  0 disk
> └─sdd1    8:49   0   3.7T  0 part
>   └─md3   9:3    0   7.3T  0 raid5 /raid3
> sde       8:64   0   3.7T  0 disk
> └─sde1    8:65   0   3.7T  0 part
>   └─md3   9:3    0   7.3T  0 raid5 /raid3
> sdf       8:80   0   3.7T  0 disk
> └─sdf1    8:81   0   3.7T  0 part
>   └─md3   9:3    0   7.3T  0 raid5 /raid3
>
> blkid shows
> /dev/sdd1: UUID="07c3d55f-2c9b-1534-6b0d-5b78dd9856ed"
> UUID_SUB="24275237-b493-169e-9e88-df0debaae551" LABEL="camelot-x:3"
> TYPE="linux_raid_member" PARTLABEL="cam-raid5-a"
> PARTUUID="729558f8-fbcf-45c1-9d9b-c6bfe6ec4bf6"
> /dev/sde1: UUID="07c3d55f-2c9b-1534-6b0d-5b78dd9856ed"
> UUID_SUB="cf36e69a-c110-b0ae-b504-fcfeb2dea024" LABEL="camelot-x:3"
> TYPE="linux_raid_member" PARTLABEL="cam-raid5-c"
> PARTUUID="654fc581-f6ef-43a4-b583-6f3cd7d52e61"
> /dev/sdf1: UUID="07c3d55f-2c9b-1534-6b0d-5b78dd9856ed"
> UUID_SUB="54fbf294-766f-c8eb-9663-02a39534003f" LABEL="camelot-x:3"
> TYPE="linux_raid_member" PARTLABEL="cam-raid5-b"
> PARTUUID="f6a7ba77-278e-4b64-8f7e-16041b85f097"
> and
> /dev/md3: UUID="97309dc0-0f54-45d8-853f-af99dead3ed2" TYPE="ext4"
>
> df -h shows
> /dev/md3        7.3T   51M  7.3T   1% /raid3
>
> QUESIONS:
>
> So why is there still a /dev/md127, and why does the array not assemble as
> /dev/md3?
> /etc/mdadm/mdadm.conf contains just the one array:
> ARRAY /dev/md3 metadata=1.2 name=camelot-x:3 UUID=07c3d55f:2c9b1534:
> 6b0d5b78:dd9856ed
> which is still what I get from
> mdadm --detail --scan
>
> mount and umount commands work as expected, both with my original
> /etc/fstab entry or with yours.  I'll leave yours in place and try a
> reboot....
>
> --
> Kevin O'Gorman
> #define QUESTION ((bb) || (!bb))   /* Shakespeare */
>
> Please consider the environment before printing this email.
>



-- 
Kevin O'Gorman
#define QUESTION ((bb) || (!bb))   /* Shakespeare */

Please consider the environment before printing this email.
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