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* MD device always starting as /dev/md127
@ 2012-09-18 23:19 Bryan Bush
  2012-09-18 23:43 ` Phil Turmel
  2012-09-18 23:44 ` NeilBrown
  0 siblings, 2 replies; 4+ messages in thread
From: Bryan Bush @ 2012-09-18 23:19 UTC (permalink / raw)
  To: linux-raid

I've moved the drives from one system to another and when the array
starts up its always /dev/md127.
/etc/mdadm/mdadm.conf has:


# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
DEVICE partitions containers

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY /dev/md1 level=raid6 metadata=1.2 num-devices=13
UUID=fa32e2c5:e7bda20b:32af7c90:c7ee61eb


mdadm --detail gives me



/dev/md127:
        Version : 1.2
  Creation Time : Sat Sep 18 17:05:52 2010
     Raid Level : raid6
     Array Size : 21488647488 (20493.17 GiB 22004.38 GB)
  Used Dev Size : 1953513408 (1863.02 GiB 2000.40 GB)
   Raid Devices : 13
  Total Devices : 13
    Persistence : Superblock is persistent

    Update Time : Tue Sep 18 17:40:47 2012
          State : clean
 Active Devices : 13
Working Devices : 13
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           Name : 1
           UUID : fa32e2c5:e7bda20b:32af7c90:c7ee61eb
         Events : 56603

    Number   Major   Minor   RaidDevice State
       0       8      177        0      active sync   /dev/sdl1
      14       8      161        1      active sync   /dev/sdk1
       2       8       81        2      active sync   /dev/sdf1
       3       8      145        3      active sync   /dev/sdj1
       4       8      209        4      active sync   /dev/sdn1
       8       8       65        5      active sync   /dev/sde1
       6       8       49        6      active sync   /dev/sdd1
       7       8       33        7      active sync   /dev/sdc1
      13       8      225        8      active sync   /dev/sdo1
      15      65       17        9      active sync   /dev/sdr1
      11      65        1       10      active sync   /dev/sdq1
      10       8      241       11      active sync   /dev/sdp1
       9       8      193       12      active sync   /dev/sdm1


If I do
mdadm --stop /dev/md127
then
mdadm --assemble --scan
It starts the array at /dev/md1

Any idea why it always starts as md127?

Thanks
-Bryan

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: MD device always starting as /dev/md127
  2012-09-18 23:19 MD device always starting as /dev/md127 Bryan Bush
@ 2012-09-18 23:43 ` Phil Turmel
  2012-09-18 23:44 ` NeilBrown
  1 sibling, 0 replies; 4+ messages in thread
From: Phil Turmel @ 2012-09-18 23:43 UTC (permalink / raw)
  To: Bryan Bush; +Cc: linux-raid

On 09/18/2012 07:19 PM, Bryan Bush wrote:
> I've moved the drives from one system to another and when the array
> starts up its always /dev/md127.

[snip /]

> If I do
> mdadm --stop /dev/md127
> then
> mdadm --assemble --scan
> It starts the array at /dev/md1
> 
> Any idea why it always starts as md127?

Update your initramfs on the new system.

HTH,

Phil


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: MD device always starting as /dev/md127
  2012-09-18 23:19 MD device always starting as /dev/md127 Bryan Bush
  2012-09-18 23:43 ` Phil Turmel
@ 2012-09-18 23:44 ` NeilBrown
  2012-09-19  0:44   ` Bryan Bush
  1 sibling, 1 reply; 4+ messages in thread
From: NeilBrown @ 2012-09-18 23:44 UTC (permalink / raw)
  To: Bryan Bush; +Cc: linux-raid

[-- Attachment #1: Type: text/plain, Size: 3489 bytes --]

On Tue, 18 Sep 2012 19:19:53 -0400 Bryan Bush <bbushvt@gmail.com> wrote:

> I've moved the drives from one system to another and when the array
> starts up its always /dev/md127.
> /etc/mdadm/mdadm.conf has:
> 
> 
> # mdadm.conf
> #
> # Please refer to mdadm.conf(5) for information about this file.
> #
> 
> # by default (built-in), scan all partitions (/proc/partitions) and all
> # containers for MD superblocks. alternatively, specify devices to scan, using
> # wildcards if desired.
> DEVICE partitions containers
> 
> # auto-create devices with Debian standard permissions
> CREATE owner=root group=disk mode=0660 auto=yes
> 
> # automatically tag new arrays as belonging to the local system
> HOMEHOST <system>
> 
> # instruct the monitoring daemon where to send mail alerts
> MAILADDR root
> 
> # definitions of existing MD arrays
> ARRAY /dev/md1 level=raid6 metadata=1.2 num-devices=13
> UUID=fa32e2c5:e7bda20b:32af7c90:c7ee61eb
> 
> 
> mdadm --detail gives me
> 
> 
> 
> /dev/md127:
>         Version : 1.2
>   Creation Time : Sat Sep 18 17:05:52 2010
>      Raid Level : raid6
>      Array Size : 21488647488 (20493.17 GiB 22004.38 GB)
>   Used Dev Size : 1953513408 (1863.02 GiB 2000.40 GB)
>    Raid Devices : 13
>   Total Devices : 13
>     Persistence : Superblock is persistent
> 
>     Update Time : Tue Sep 18 17:40:47 2012
>           State : clean
>  Active Devices : 13
> Working Devices : 13
>  Failed Devices : 0
>   Spare Devices : 0
> 
>          Layout : left-symmetric
>      Chunk Size : 64K
> 
>            Name : 1
>            UUID : fa32e2c5:e7bda20b:32af7c90:c7ee61eb
>          Events : 56603
> 
>     Number   Major   Minor   RaidDevice State
>        0       8      177        0      active sync   /dev/sdl1
>       14       8      161        1      active sync   /dev/sdk1
>        2       8       81        2      active sync   /dev/sdf1
>        3       8      145        3      active sync   /dev/sdj1
>        4       8      209        4      active sync   /dev/sdn1
>        8       8       65        5      active sync   /dev/sde1
>        6       8       49        6      active sync   /dev/sdd1
>        7       8       33        7      active sync   /dev/sdc1
>       13       8      225        8      active sync   /dev/sdo1
>       15      65       17        9      active sync   /dev/sdr1
>       11      65        1       10      active sync   /dev/sdq1
>       10       8      241       11      active sync   /dev/sdp1
>        9       8      193       12      active sync   /dev/sdm1
> 
> 
> If I do
> mdadm --stop /dev/md127
> then
> mdadm --assemble --scan
> It starts the array at /dev/md1
> 
> Any idea why it always starts as md127?
>

My guess is that it is being started while the initrd is running, and the
initrd doesn't have that mdadm.conf.
So mdadm doesn't know what number to associated with the uuid, and so chooses
an unused one.

The metadata does say "Name : 1", but that isn't trusted unless there is some
reason to believe that the array belongs to "this" host.

If you:
  mdadm -S /dev/md127
  mdadm -A /dev/md1 --update=name /dev/sd[lkfjnedcorqpm]1
then it should update the metadata so that it is known to belong to "this"
host.  Then providing that the hostname is set during the initrd, it should
get the right name.
Or maybe arrange for the ARRAY entry to appear in the mdadm.conf in the
initrd.

NeilBrown


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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: MD device always starting as /dev/md127
  2012-09-18 23:44 ` NeilBrown
@ 2012-09-19  0:44   ` Bryan Bush
  0 siblings, 0 replies; 4+ messages in thread
From: Bryan Bush @ 2012-09-19  0:44 UTC (permalink / raw)
  To: linux-raid

an
update-initramfs -u
fixed it.
Thanks
-Bryan


On Tue, Sep 18, 2012 at 7:44 PM, NeilBrown <neilb@suse.de> wrote:
> On Tue, 18 Sep 2012 19:19:53 -0400 Bryan Bush <bbushvt@gmail.com> wrote:
>
>> I've moved the drives from one system to another and when the array
>> starts up its always /dev/md127.
>> /etc/mdadm/mdadm.conf has:
>>
>>
>> # mdadm.conf
>> #
>> # Please refer to mdadm.conf(5) for information about this file.
>> #
>>
>> # by default (built-in), scan all partitions (/proc/partitions) and all
>> # containers for MD superblocks. alternatively, specify devices to scan, using
>> # wildcards if desired.
>> DEVICE partitions containers
>>
>> # auto-create devices with Debian standard permissions
>> CREATE owner=root group=disk mode=0660 auto=yes
>>
>> # automatically tag new arrays as belonging to the local system
>> HOMEHOST <system>
>>
>> # instruct the monitoring daemon where to send mail alerts
>> MAILADDR root
>>
>> # definitions of existing MD arrays
>> ARRAY /dev/md1 level=raid6 metadata=1.2 num-devices=13
>> UUID=fa32e2c5:e7bda20b:32af7c90:c7ee61eb
>>
>>
>> mdadm --detail gives me
>>
>>
>>
>> /dev/md127:
>>         Version : 1.2
>>   Creation Time : Sat Sep 18 17:05:52 2010
>>      Raid Level : raid6
>>      Array Size : 21488647488 (20493.17 GiB 22004.38 GB)
>>   Used Dev Size : 1953513408 (1863.02 GiB 2000.40 GB)
>>    Raid Devices : 13
>>   Total Devices : 13
>>     Persistence : Superblock is persistent
>>
>>     Update Time : Tue Sep 18 17:40:47 2012
>>           State : clean
>>  Active Devices : 13
>> Working Devices : 13
>>  Failed Devices : 0
>>   Spare Devices : 0
>>
>>          Layout : left-symmetric
>>      Chunk Size : 64K
>>
>>            Name : 1
>>            UUID : fa32e2c5:e7bda20b:32af7c90:c7ee61eb
>>          Events : 56603
>>
>>     Number   Major   Minor   RaidDevice State
>>        0       8      177        0      active sync   /dev/sdl1
>>       14       8      161        1      active sync   /dev/sdk1
>>        2       8       81        2      active sync   /dev/sdf1
>>        3       8      145        3      active sync   /dev/sdj1
>>        4       8      209        4      active sync   /dev/sdn1
>>        8       8       65        5      active sync   /dev/sde1
>>        6       8       49        6      active sync   /dev/sdd1
>>        7       8       33        7      active sync   /dev/sdc1
>>       13       8      225        8      active sync   /dev/sdo1
>>       15      65       17        9      active sync   /dev/sdr1
>>       11      65        1       10      active sync   /dev/sdq1
>>       10       8      241       11      active sync   /dev/sdp1
>>        9       8      193       12      active sync   /dev/sdm1
>>
>>
>> If I do
>> mdadm --stop /dev/md127
>> then
>> mdadm --assemble --scan
>> It starts the array at /dev/md1
>>
>> Any idea why it always starts as md127?
>>
>
> My guess is that it is being started while the initrd is running, and the
> initrd doesn't have that mdadm.conf.
> So mdadm doesn't know what number to associated with the uuid, and so chooses
> an unused one.
>
> The metadata does say "Name : 1", but that isn't trusted unless there is some
> reason to believe that the array belongs to "this" host.
>
> If you:
>   mdadm -S /dev/md127
>   mdadm -A /dev/md1 --update=name /dev/sd[lkfjnedcorqpm]1
> then it should update the metadata so that it is known to belong to "this"
> host.  Then providing that the hostname is set during the initrd, it should
> get the right name.
> Or maybe arrange for the ARRAY entry to appear in the mdadm.conf in the
> initrd.
>
> NeilBrown
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2012-09-19  0:44 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2012-09-18 23:19 MD device always starting as /dev/md127 Bryan Bush
2012-09-18 23:43 ` Phil Turmel
2012-09-18 23:44 ` NeilBrown
2012-09-19  0:44   ` Bryan Bush

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