Duplicate UUID on boot generated by update

MDADM Serious bug

The Environment

A RAID 1 environment, originally with 2 hard drives containing both UBUNTU Server and data files as /dev/md/1 & /dev/md/0

On upgrade (sudo apt upgrade) mdadm.conf updated to include two sets of

“# definitions of existing MD arrays

ARRAY /dev/md/1 metadata=1.2 name=acas6:1 UUID=blah1:…...

ARRAY /dev/md/0 metadata=1.2 name=acas6:0 UUID=blah0:…...

# This file was auto-generated on Sun 18 Nov…...

# by mkconf $ld$

ARRAY /dev/md/1 metadata=1.2 name=acas6:1 UUID=blah1:…...

ARRAY /dev/md/0 metadata=1.2 name=acas6:0 UUID=blah0:…...”

The UUIDs corresponding to the md/0 were identical as were those for md/1.

The mdadm.conf file was incorporated in the OS boot image

Which resulted on boot in repeated

“mdadm: Duplicate MD device names in conf file found.

mdadm: Device: UUID-blah0:…….

Done.

Gave up waiting for root file system devices. Common problems:

– Boot args (cat/proc/cmdline)

--Check rootdelay= (…)

– Missing modules (cat /proc/modules: ls/dev)

ALERT ! UUID=blah2:…….. does not exist. Dropping to shell!”

Editing mdadm,conf in the boot image was viewed as too risky.

BOOT Repair does not work (It appears just to accept the two sets of identical ARRAY entries in mdadm.conf)

Nor did Gparted+ Gpart fix anything.

Various incantations to mdadm did not work either.

Eventually I resorted to reinstall of UBUNTU 18.04 server utilising one of the two RAID disks and two extra disks which were used as the basis of a new RAID1 array.

Then mounted the other original single RAID disk as read only.

UBUNTU Server 18.04 proceedure does not appear to support incorporating a boot disk into a RAID 1 array.

Regardless it would be really useful if updates involving mdadm checked to ensure that it was not producing two identical copies of ARRAY entries with identical Device and UUIDs. It appears to just scan and append to mddm.conf though some hidden special character may be lurking somewhere.

It would also be useful if on boot mdadm checked if duplicate entries were identical and if so simply act on one entry and ignored the other.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: mdadm 4.1~rc1-3~ubuntu18.04.2
ProcVersionSignature: Ubuntu 4.15.0-52.56-generic 4.15.18
Uname: Linux 4.15.0-52-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Tue Jun 18 20:39:48 2019
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-08-01 (1416 days ago)
InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422)
MDadmExamine.dev.sda: Error: command ['/sbin/mdadm', '-E', '/dev/sda'] failed with exit code 1: mdadm: cannot open /dev/sda: Permission denied
MDadmExamine.dev.sda1: Error: command ['/sbin/mdadm', '-E', '/dev/sda1'] failed with exit code 1: mdadm: cannot open /dev/sda1: Permission denied
MDadmExamine.dev.sda2: Error: command ['/sbin/mdadm', '-E', '/dev/sda2'] failed with exit code 1: mdadm: cannot open /dev/sda2: Permission denied
MDadmExamine.dev.sda3: Error: command ['/sbin/mdadm', '-E', '/dev/sda3'] failed with exit code 1: mdadm: cannot open /dev/sda3: Permission denied
MDadmExamine.dev.sda5: Error: command ['/sbin/mdadm', '-E', '/dev/sda5'] failed with exit code 1: mdadm: cannot open /dev/sda5: Permission denied
MDadmExamine.dev.sda6: Error: command ['/sbin/mdadm', '-E', '/dev/sda6'] failed with exit code 1: mdadm: cannot open /dev/sda6: Permission denied
MDadmExamine.dev.sdb: Error: command ['/sbin/mdadm', '-E', '/dev/sdb'] failed with exit code 1: mdadm: cannot open /dev/sdb: Permission denied
MDadmExamine.dev.sdb1: Error: command ['/sbin/mdadm', '-E', '/dev/sdb1'] failed with exit code 1: mdadm: cannot open /dev/sdb1: Permission denied
MDadmExamine.dev.sdb2: Error: command ['/sbin/mdadm', '-E', '/dev/sdb2'] failed with exit code 1: mdadm: cannot open /dev/sdb2: Permission denied
MDadmExamine.dev.sdb5: Error: command ['/sbin/mdadm', '-E', '/dev/sdb5'] failed with exit code 1: mdadm: cannot open /dev/sdb5: Permission denied
MDadmExamine.dev.sdc: Error: command ['/sbin/mdadm', '-E', '/dev/sdc'] failed with exit code 1: mdadm: cannot open /dev/sdc: Permission denied
MDadmExamine.dev.sdc1: Error: command ['/sbin/mdadm', '-E', '/dev/sdc1'] failed with exit code 1: mdadm: cannot open /dev/sdc1: Permission denied
MDadmExamine.dev.sdc2: Error: command ['/sbin/mdadm', '-E', '/dev/sdc2'] failed with exit code 1: mdadm: cannot open /dev/sdc2: Permission denied
MDadmExamine.dev.sdc3: Error: command ['/sbin/mdadm', '-E', '/dev/sdc3'] failed with exit code 1: mdadm: cannot open /dev/sdc3: Permission denied
MDadmExamine.dev.sdc5: Error: command ['/sbin/mdadm', '-E', '/dev/sdc5'] failed with exit code 1: mdadm: cannot open /dev/sdc5: Permission denied
MDadmExamine.dev.sdc6: Error: command ['/sbin/mdadm', '-E', '/dev/sdc6'] failed with exit code 1: mdadm: cannot open /dev/sdc6: Permission denied
MDadmExamine.dev.sdd: Error: command ['/sbin/mdadm', '-E', '/dev/sdd'] failed with exit code 1: mdadm: cannot open /dev/sdd: Permission denied
MDadmExamine.dev.sdd1: Error: command ['/sbin/mdadm', '-E', '/dev/sdd1'] failed with exit code 1: mdadm: cannot open /dev/sdd1: Permission denied
MDadmExamine.dev.sdd2: Error: command ['/sbin/mdadm', '-E', '/dev/sdd2'] failed with exit code 1: mdadm: cannot open /dev/sdd2: Permission denied
MDadmExamine.dev.sdd3: Error: command ['/sbin/mdadm', '-E', '/dev/sdd3'] failed with exit code 1: mdadm: cannot open /dev/sdd3: Permission denied
MDadmExamine.dev.sdd5: Error: command ['/sbin/mdadm', '-E', '/dev/sdd5'] failed with exit code 1: mdadm: cannot open /dev/sdd5: Permission denied
MDadmExamine.dev.sdd6: Error: command ['/sbin/mdadm', '-E', '/dev/sdd6'] failed with exit code 1: mdadm: cannot open /dev/sdd6: Permission denied
MachineType: Gigabyte Technology Co., Ltd. H97M-HD3
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-52-generic root=UUID=81a726f4-12b2-4a64-bf86-133e3f77e472 ro
SourcePackage: mdadm
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/05/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F6
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: H97M-HD3
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF6:bd12/05/2014:svnGigabyteTechnologyCo.,Ltd.:pnH97M-HD3:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnH97M-HD3:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: H97M-HD3
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
etc.blkid.tab: Error: [Errno 2] No such file or directory: '/etc/blkid.tab'