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Issues with RAID- creating as /dev/md127 instead of what's in the config

Hi,
Recently, I decided to change my partition scheme for my home server. I had a RAID0 that previously spanned three disks and now I only want it to span two. Getting rid of the old one was easy. But getting the new one to work has been a real pain.

It's running Debian Jessie.

For starters, here's my /etc/mdadm/mdadm.conf:

Code:

root@maples-server:~# cat /etc/mdadm/mdadm.conf 

# 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

DEVICE /dev/sdb1 /dev/sdc1



# 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/md0 metadata=1.2 UUID=032e4ab2:53ac5db8:98806abd:420716a5 devices=/dev/sdb1,/dev/sdc1

As you can see, I have it specified to setup the RAID as /dev/md0. But every time I reboot, my /proc/mdstat shows:

Code:

root@maples-server:~# cat /proc/mdstat 

Personalities : [raid0] 

md127 : active raid0 sdc1[1] sdb1[0]

      488016896 blocks super 1.2 512k chunks

      

unused devices: <none>

I can confirm that it's actually md127 by looking at /dev:

Code:

root@maples-server:~# ls -l /dev/md*

brw-rw---- 1 root disk 9, 127 May  2 20:17 /dev/md127



/dev/md:

total 0

lrwxrwxrwx 1 root root 8 May  2 20:17 maples-server:0 -> ../md127

And here's a bit more info:

Code:

root@maples-server:~# mdadm --detail --scan

ARRAY /dev/md/maples-server:0 metadata=1.2 name=maples-server:0 UUID=032e4ab2:53ac5db8:98806abd:420716a5

I've tried adding all sorts of options to /etc/mdadm/mdadm.conf, ranging from just the output of the above command (only changing "/dev/md/maples-server:0" to "/dev/md0") to what you see at the top. Nothing seems to be making a difference.

Does anyone have any ideas?

As the kids say "Too Much Information!". Change you mdadm.conf ARRAY line to:

Code:

ARRAY /dev/md0 UUID=032e4ab2:53ac5db8:98806abd:420716a5

Thanks for the reply!

Unfortunately, that doesn't seem to do the trick...

Code:

root@maples-server:~# cat /etc/mdadm/mdadm.conf 

# 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/md0 metadata=1.2 UUID=032e4ab2:53ac5db8:98806abd:420716a5 devices=/dev/sdb1,/dev/sdc1

ARRAY /dev/md0 UUID=032e4ab2:53ac5db8:98806abd:420716a5 



root@maples-server:~# cat /proc/mdstat 

Personalities : [raid0] 

md127 : active raid0 sdb1[0] sdc1[1]

      488016896 blocks super 1.2 512k chunks

      

unused devices: <none>

root@maples-server:~# ls /dev/md* -l

brw-rw---- 1 root disk 9, 127 May  2 21:35 /dev/md127



/dev/md:

total 0

lrwxrwxrwx 1 root root 8 May  2 21:35 maples-server:0 -> ../md127

One other thing that might or might not mean anything: The original RAID was created with the Debian installer when I first installed the system. I don't know if there's a difference or not, but I thought I would throw it out there just in case.

Have you changed the hostname since you created the array? Check the output from

Code:

mdadm --detail /dev/md127

No, the hostname is still the same.

Code:

root@maples-server:~# mdadm --detail /dev/md127 

/dev/md127:

        Version : 1.2

  Creation Time : Sat May  2 20:02:54 2015

    Raid Level : raid0

    Array Size : 488016896 (465.41 GiB 499.73 GB)

  Raid Devices : 2

  Total Devices : 2

    Persistence : Superblock is persistent



    Update Time : Sat May  2 20:02:54 2015

          State : clean 

 Active Devices : 2

Working Devices : 2

 Failed Devices : 0

  Spare Devices : 0



    Chunk Size : 512K



          Name : maples-server:0  (local to host maples-server)

          UUID : 032e4ab2:53ac5db8:98806abd:420716a5

        Events : 0



    Number  Major  Minor  RaidDevice State

      0      8      17        0      active sync  /dev/sdb1

      1      8      33        1      active sync  /dev/sdc1

It's been "maples-server" since day one.

Check the log from the reboot

Code:

dmesg |grep md

There is a lot of non-mdadm output, I've bolded (hopefully) all of the relevant parts. I've also "filled in" one line that applied to another mdadm line that just didn't happen to contain "md"

Code:

[    0.000000] Linux version 3.16.0-4-amd64 (debian-kernel@lists.debian.org) (gcc version 4.8.4 (Debian 4.8.4-1) ) #1 SMP Debian 3.16.7-ckt9-3~deb8u1 (2015-04-24)

[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.16.0-4-amd64 root=UUID=3b4354d8-2380-4c70-9f9f-d8c1f5de5233 ro quiet

[    0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.16.0-4-amd64 root=UUID=3b4354d8-2380-4c70-9f9f-d8c1f5de5233 ro quiet

[    0.535937] AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>

[    0.600969] systemd-udevd[63]: starting version 215

[    0.601363] random: systemd-udevd urandom read with 1 bits of entropy available

[    0.636154] usb usb1: Manufacturer: Linux 3.16.0-4-amd64 ehci_hcd

[    0.636925] usb usb3: Manufacturer: Linux 3.16.0-4-amd64 uhci_hcd

[    0.637669] usb usb4: Manufacturer: Linux 3.16.0-4-amd64 uhci_hcd

[    0.638639] usb usb5: Manufacturer: Linux 3.16.0-4-amd64 uhci_hcd

[    0.639510] usb usb6: Manufacturer: Linux 3.16.0-4-amd64 uhci_hcd

[    0.640243] usb usb2: Manufacturer: Linux 3.16.0-4-amd64 xhci_hcd

[    0.640582] usb usb7: Manufacturer: Linux 3.16.0-4-amd64 xhci_hcd

[    0.647577] ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0x40b0 irq 14

[    0.647579] ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0x40b8 irq 15

[    1.224284] md: bind<sdb1>

[    1.249833] md: bind<sdc1>

[    1.251381] md: raid0 personality registered for level 0

[    1.251611] md/raid0:md127: md_size is 976033792 sectors.

[    1.251614] md: RAID0 configuration for md127 - 1 zone

[    1.251615] md: zone0=[sdb1/sdc1]

[    1.251619]      zone-offset=        0KB, device-offset=        0KB, size= 488016896KB

[    1.251629] md127: detected capacity change from 0 to 499729301504

[    1.255858]  md127: unknown partition table

[    5.172883] systemd-udevd[200]: starting version 215

[    9.427196] EXT4-fs (md127): mounting ext3 file system using the ext4 subsystem

[    9.446980] EXT4-fs (md127): mounted filesystem with ordered data mode. Opts: (null)

[    9.927294] systemd-journald[215]: Received request to flush runtime journal from PID 1

The raid is being automatically assembled by the kernel, which is why mdadm.conf doesn't matter. I don't know why it isn't using the ":0" part of the name to make it md0.

So there's no way to make the kernel give it a certain name?

I suspect you can update the initramfs with the correct mdadm.conf to fix this. See this post:

http://unix.stackexchange.com/questi...bled-at-bootup

Quote:

Originally Posted by smallpond (Post 5357625)

I suspect you can update the initramfs with the correct mdadm.conf to fix this. See this post:

http://unix.stackexchange.com/questi...bled-at-bootup

That did it!

For me, all I had to do was run

Code:

update-initramfs -u

and reboot, and now it's working the way it should!

Thank you!