Posts by abelvill

    Hi, I have a RAID 5 with 4 disks that has run smoothly for 5 years. A few days ago one of the disks failed. I removed the damaged disk and put a new one started to recreate the RAID (mdadm --add /dev/md127 /dev/sdb) but it failed at about 20%.

    Now I get the following message:

    mdadm --add /dev/md127 /dev/sdb
    mdadm: Cannot get array info for /dev/md127

    I've tried to recreate the RAID:

    mdadm --assemble --run --force /dev/md127 /dev/sd[bcde]
    mdadm: Cannot assemble mbr metadata on /dev/sdb

    I tried many things, like deleting the mdadm configuration file, but without success.

    I have formatted the new disc but not assigned a file format.

    gdisk /dev/sdb

    I expose the necessary data to receive help:

    1. cat /proc/mdstat

    Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
    md127 : inactive sdc[1](S) sdd[2](S) sde[3](S)
    8790796680 blocks super 1.2

    unused devices: <none>

    2. blkid

    /dev/sda1: UUID="5978d112-caf8-4756-9b80-714132f07bad" TYPE="ext4" PARTUUID="6efe7dd4-01"
    /dev/sda5: UUID="6d15bc03-d534-4e44-ab94-36eb3533791d" TYPE="swap" PARTUUID="6efe7dd4-05"
    /dev/sdc: UUID="04366c8b-6451-f12b-e9e0-6d4d88ab6493" UUID_SUB="9be5592b-cd79-9607-d85c-94f07e57391c" LABEL="NAS:NAS" TYPE="linux_raid_member"
    /dev/sdd: UUID="04366c8b-6451-f12b-e9e0-6d4d88ab6493" UUID_SUB="c8f4f160-c790-98f8-8608-5797e73b2c3c" LABEL="NAS:NAS" TYPE="linux_raid_member"
    /dev/sde: UUID="04366c8b-6451-f12b-e9e0-6d4d88ab6493" UUID_SUB="588fd1a3-cc0e-f274-8f1c-554bb8a5bde7" LABEL="NAS:NAS" TYPE="linux_raid_member"
    /dev/sdb1: PARTLABEL="Linux filesystem" PARTUUID="3e2cfb1b-82df-482e-bd55-a356582d4667"

    3. fdisk -l | grep "Disk "

    Disk /dev/sda: 29.8 GiB, 32017047552 bytes, 62533296 sectors
    Disk identifier: 0x6efe7dd4
    Disk /dev/sdb: 2.7 TiB, 3000592982016 bytes, 5860533168 sectors
    Disk identifier: 2EEB399B-3706-4153-A4E5-58A73B886706
    Disk /dev/sdc: 2.7 TiB, 3000592982016 bytes, 5860533168 sectors
    Disk /dev/sdd: 2.7 TiB, 3000592982016 bytes, 5860533168 sectors
    Disk /dev/sde: 2.7 TiB, 3000592982016 bytes, 5860533168 sectors

    4. cat /etc/mdadm/mdadm.conf

    # mdadm.conf

    DEVICE partitions

    # 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>

    # definitions of existing MD arrays
    ARRAY /dev/md/NAS metadata=1.2 name=NAS:NAS UUID=04366c8b:6451f12b:e9e06d4d:88ab6493

    # instruct the monitoring daemon where to send mail alerts
    MAILFROM rootroot@NAS:~#

    5. mdadm --detail --scan --verbose

    INACTIVE-ARRAY /dev/md127 num-devices=3 metadata=1.2 name=NAS:NAS UUID=04366c8b:6451f12b:e9e06d4d:88ab6493

    6. There are 4 WD NAS Red 3TB disks

    7. The RAID stopped working when bad sectors were detected on one of the disks.

    Thank you in advance for your help.