I have recently upgraded the hardware in my home server (Mainboard, CPU, RAM) from an old i3-540 (Clarkdale) to a new i5-7400 (Kaby Lake).
I'm running Linux Mint 18 and had configured a software RAID6 with 5 drives with mdadm. I read up on the procedure of moving the raid to the new system and was assured that I just had to run
mdadm --assemble --scan
and the drives would be detected.
Unfortunately this was not the case. After upgrading the hardware and booting up the old OS with the new hardware, everything seemed to run fine, but after I connected the RAID drives, not a single one of them was detected by mdadm.
$ mdadm --assemble --scan --verbose mdadm: looking for devices for further assembly mdadm: Cannot assemble mbr metadata on /dev/sdf mdadm: Cannot assemble mbr metadata on /dev/sde mdadm: Cannot assemble mbr metadata on /dev/sdd mdadm: Cannot assemble mbr metadata on /dev/sdc mdadm: Cannot assemble mbr metadata on /dev/sdb mdadm: No arrays found in config file or automatically
As far as I remember, the RAID was created directly on the disks (no partitions). All drives are now detected with 100% free space and no partitions.
GDisk shows the protective MBR on all drives as this:
Disk size is 15628053168 sectors (7.3 TiB) MBR disk identifier: 0x00000000 MBR partitions: Number Boot Start Sector End Sector Status Code 1 1 4294967295 primary 0xEE
The drives themselves seem to be fine, there are no S.M.A.R.T. errors on any of them.
Is it possible that the superblocks got overwritten somehow when upgrading? Could it be that the UEFI bios on the new MB somehow scrambled them (old MB: Gigabyte GA-H55N-USB3, new MB: ASRock Z270M-ITX/ac)?
I read that it might be possible to "just recreate" the array by running
mdadm --create ...
with the same settings again, but since all drives are connected to new SATA ports I don't know any kind of order they were in (which seems to be important) and I'm very hesitant to just trial and error this.
I'd appreciate any kind of help you can give or pointers how to solve this.
Maybe these outputs are helpful:
$ mdadm --assemble --run --force /dev/md0 /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf mdadm: Cannot assemble mbr metadata on /dev/sdb mdadm: /dev/sdb has no superblock - assembly aborted $ sudo fdisk -l /dev/sdb Medium /dev/sdb: 7,3 TiB, 8001563222016 Bytes, 15628053168 Sektoren Einheiten: sectors von 1 * 512 = 512 Bytes Sektorengröße (logisch/physisch): 512 Bytes / 4096 Bytes I/O Größe (minimal/optimal): 4096 Bytes / 4096 Bytes Typ der Medienbezeichnung: gpt Medienkennung: 06B4B33D-1857-4745-8A54-86B65E5244D5 $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] unused devices: <none> $ parted /dev/sdb --align optimal unit MiB print Modell: ATA ST8000VN0022-2EL (scsi) Festplatte /dev/sdb: 7630885MiB Sektorgröße (logisch/physisch): 512B/4096B Partitionstabelle: gpt Disk-Flags: Nummer Anfang Ende Größe Dateisystem Name Flags