ReaR confuses Device Mapper Multipathing (DM) devices with Non-volatile Memory Express™ (NVMe™) multipathing devices.

ReaR version ("/usr/sbin/rear -V"): Relax-and-Recover 2.6 / 2020-06-17

OS version ("cat /etc/os-release" or "lsb_release -a" or "cat /etc/rear/os.conf"):


NAME="Oracle Linux Server"
VERSION="8.5"
ID="ol"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="8.5"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Oracle Linux Server 8.5"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:oracle:linux:8:5:server"
HOME_URL="https://linux.oracle.com/"
BUG_REPORT_URL="https://bugzilla.oracle.com/"

ORACLE_BUGZILLA_PRODUCT="Oracle Linux 8" ORACLE_BUGZILLA_PRODUCT_VERSION=8.5 ORACLE_SUPPORT_PRODUCT="Oracle Linux" ORACLE_SUPPORT_PRODUCT_VERSION=8.5


* ReaR configuration files ("cat /etc/rear/site.conf" and/or "cat /etc/rear/local.conf"):

OUTPUT=ISO OUTPUT_URL=nfs://193.14.236.134/volume1/Rear BACKUP=NETFS BACKUP_URL=nfs://193.14.236.134/volume1/Rear BACKUP_PROG_EXCLUDE=("${BACKUP_PROG_EXCLUDE[@]}" '/media' '/var/tmp' '/var/crash' '/u02' '/dev/nvme0n1' '/dev/nvme1n1' '/dev/nvme2n1' '/dev/nvme3n1' '/dev/nvme4n1' '/dev/nvme5n1' ) NETFS_KEEP_OLD_BACKUP_COPY= UEFI_BOOTLOADER=/boot/efi/EFI/redhat/grubx64.efi SECURE_BOOT_BOOTLOADER=/boot/efi/EFI/redhat/shimx64.efi EXCLUDE_MOUNTPOINTS=( '/u03/flashdata/ZVK_MUC' '/u02/oradata/ZVK_MUC' ) AUTOEXCLUDE_MULTIPATH=n BOOT_OVER_SAN=y AUTORESIZE_PARTITIONS=true AUTOSHRINK_DISK_SIZE_LIMIT_PERCENTAGE=100


* Hardware vendor/product (PC or PowerNV BareMetal or ARM) or VM (KVM guest or PowerVM LPAR):
PC

* System architecture (x86 compatible or PPC64/PPC64LE or what exact ARM device):
x86 

* Firmware (BIOS or UEFI or Open Firmware) and bootloader (GRUB or ELILO or Petitboot):
UEFI and bootloader GRUB

* Storage (local disk or SSD) and/or SAN (FC or iSCSI or FCoE) and/or multipath (DM or NVMe):
SSD (DM **and** NVMe)

* Storage layout ("lsblk -ipo NAME,KNAME,PKNAME,TRAN,TYPE,FSTYPE,LABEL,SIZE,MOUNTPOINT"):

NAME KNAME PKNAME TRAN TYPE FSTYPE LABEL SIZE MOUNTPOINT /dev/sda /dev/sda sata disk isw_raid_member 447,1G |-/dev/sda1 /dev/sda1 /dev/sda part vfat 600M |-/dev/sda2 /dev/sda2 /dev/sda part xfs 1G |-/dev/sda3 /dev/sda3 /dev/sda part LVM2_member 154G |-/dev/sda4 /dev/sda4 /dev/sda part LVM2_member 269,2G -/dev/md126 /dev/md126 /dev/sda raid1 424,8G |-/dev/md126p1 /dev/md126p1 /dev/md126 md vfat 600M /boot/efi |-/dev/md126p2 /dev/md126p2 /dev/md126 md xfs 1G /boot |-/dev/md126p3 /dev/md126p3 /dev/md126 md LVM2_member 154G | |-/dev/mapper/ol-root /dev/dm-0 /dev/md126p3 lvm xfs 30G / | |-/dev/mapper/ol-swap /dev/dm-1 /dev/md126p3 lvm swap 24G [SWAP] |-/dev/mapper/ol-u01 /dev/dm-11 /dev/md126p3 lvm xfs 100G /u01 -/dev/md126p4 /dev/md126p4 /dev/md126 md LVM2_member 269,2G /dev/sdb /dev/sdb sata disk isw_raid_member 447,1G |-/dev/sdb1 /dev/sdb1 /dev/sdb part vfat 600M |-/dev/sdb2 /dev/sdb2 /dev/sdb part xfs 1G |-/dev/sdb3 /dev/sdb3 /dev/sdb part LVM2_member 154G |-/dev/sdb4 /dev/sdb4 /dev/sdb part LVM2_member 269,2G -/dev/md126 /dev/md126 /dev/sdb raid1 424,8G |-/dev/md126p1 /dev/md126p1 /dev/md126 md vfat 600M /boot/efi |-/dev/md126p2 /dev/md126p2 /dev/md126 md xfs 1G /boot |-/dev/md126p3 /dev/md126p3 /dev/md126 md LVM2_member 154G | |-/dev/mapper/ol-root /dev/dm-0 /dev/md126p3 lvm xfs 30G / | |-/dev/mapper/ol-swap /dev/dm-1 /dev/md126p3 lvm swap 24G [SWAP] | -/dev/mapper/ol-u01 /dev/dm-11 /dev/md126p3 lvm xfs 100G /u01 -/dev/md126p4 /dev/md126p4 /dev/md126 md LVM2_member 269,2G /dev/nvme0n1 /dev/nvme0n1 nvme disk 5,8T -/dev/nvme0n1p1 /dev/nvme0n1p1 /dev/nvme0n1 nvme part LVM2_member 5,8T |-/dev/mapper/vg_oracle-u02_zvk_muc /dev/dm-2 /dev/nvme0n1p1 lvm ext4 2,5T /u02/oradata/ZVK_MUC |-/dev/mapper/vg_oracle-u02_zvk_da /dev/dm-3 /dev/nvme0n1p1 lvm ext4 1000G /u02/oradata/ZVK_DA |-/dev/mapper/vg_oracle-u02_bsv /dev/dm-4 /dev/nvme0n1p1 lvm ext4 1000G /u02/oradata/BSV |-/dev/mapper/vg_oracle-u02_kvv /dev/dm-5 /dev/nvme0n1p1 lvm ext4 500G /u02/oradata/KVV -/dev/mapper/vg_oracle-u02_daisy /dev/dm-6 /dev/nvme0n1p1 lvm ext4 500G /u02/oradata/DAISY /dev/nvme3n1 /dev/nvme3n1 nvme disk 2,9T /dev/nvme1n1 /dev/nvme1n1 nvme disk 5,8T -/dev/nvme1n1p1 /dev/nvme1n1p1 /dev/nvme1n1 nvme part LVM2_member 5,8T |-/dev/mapper/vg_oracle-u02_vip /dev/dm-7 /dev/nvme1n1p1 lvm ext4 500G /u02/oradata/VIP |-/dev/mapper/vg_oracle-u02_vbo--portal /dev/dm-8 /dev/nvme1n1p1 lvm ext4 500G /u02/oradata/VBO-Portal |-/dev/mapper/vg_oracle-u02_bsv--portal /dev/dm-9 /dev/nvme1n1p1 lvm ext4 500G /u02/oradata/BSV-Portal -/dev/mapper/vg_oracle-u02_vbo /dev/dm-10 /dev/nvme1n1p1 lvm ext4 500G /u02/oradata/VBO /dev/nvme4n1 /dev/nvme4n1 nvme disk 2,9T /dev/nvme2n1 /dev/nvme2n1 nvme disk 2,9T `-/dev/nvme2n1p1 /dev/nvme2n1p1 /dev/nvme2n1 nvme part ext4 2,9T /u03/flashdata/ZVK_MUC /dev/nvme5n1 /dev/nvme5n1 nvme disk 2,9T


* Description of the issue (ideally so that others can reproduce it):

My analysis of the attached files revealed the following facts:

ReaR confuses DM (Device Mapper Multipathing) multipathing devices with NVMe™ (Non-volatile Memory Express™) multipathing devices.

In the original disklayout.conf file, ReaR correctly detects the following DM multipath devices (Sata devices):

/dev/sda (sata) /dev/sdb (sata)


ReaR also correctly detects the following (NVMe™) multipathing devices:

/dev/nvme0n1 (nvme) /dev/nvme1n1 (nvme) /dev/nvme2n1 (nvme) /dev/nvme3n1 (nvme) /dev/nvme4n1 (nvme) /dev/nvme5n1 (nvme)



When testing disaster recovery, ReaR can no longer correctly reconstruct the multipathing devices.

/dev/sdb correctly recognizes ReaR as a SATA device.
/dev/sda does not correctly recognize ReaR as a SATA, but incorrectly as an NVME device 
ReaR incorrectly links /dev/sda (sata) to /dev/nvme0n1 (nvme)

ReaR then fails with the error message during disaster recovery 
ERROR: No file system mounted on mnt/local 

AUTOEXCLUDE_MULTIPATH=n does not solve the problem.

What measures are required for proper disaster recovery?

* Workaround, if any:
unidentified

* Attachments, as applicable ("rear -D mkrescue/mkbackup/recover" debug log files):
* original_disklayout.conf.txt: (https://github.com/rear/rear/files/15399959/original_disklayout.conf.txt)
* recovered_disklayout conf: (https://github.com/rear/rear/assets/158028301/ebd75c54-34fc-423b-9d3d-bfacdf6a3670)
* var_log_rear_rear-ora: (https://github.com/rear/rear/assets/158028301/1438de1e-328c-42f7-aa82-42cdca1c14ff)

rear / rear

ReaR confuses Device Mapper Multipathing (DM) devices with Non-volatile Memory Express™ (NVMe™) multipathing devices. #3230