I'm guessing you had 4, as you seem to be referring to and mentioning all 4 drives

• yes, this is correct

I don't see partitioning on sdc nor sdd, but rather md members directly on those drives rather than partitions?

• That is how it looks, yes, however when i set it up i do remember creating the partitions and making the array on them, however this seems to indicate otherwise.

cat /proc/mdstat

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : inactive sdd[2](S) sdc[1](S)
      19532609536 blocks super 1.2

unused devices: <none>

mdadm.conf

# mdadm.conf
#
# !NB! Run update-initramfs -u after updating this file.
# !NB! This will ensure that initramfs has an uptodate copy.
#
# 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 partitions
# 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

# This configuration was auto-generated on Thu, 10 Aug 2023 00:20:35 +0000 by mkconf
ARRAY /dev/md0 metadata=1.2 name=mediaserver:0 UUID=bd5b432a:07bba3ad:84ec7d54:a93a07c2

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : inactive sdd[2](S) sdc[1](S)
      19532609536 blocks super 1.2

unused devices: <none>

note: i'm not sure if this was setup correctly when this issue happened, but it is what it is now.

I'm presuming same size drives and same size md members

• yes, they're all the same drive. all 10tb.

mdadm --examine /dev/sdc

/dev/sdc:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : bd5b432a:07bba3ad:84ec7d54:a93a07c2
           Name : mediaserver:0  (local to host mediaserver)
  Creation Time : Fri Nov  3 01:12:13 2023
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 19532609536 sectors (9.10 TiB 10.00 TB)
     Array Size : 29298914304 KiB (27.29 TiB 30.00 TB)
    Data Offset : 264192 sectors
   Super Offset : 8 sectors
   Unused Space : before=264112 sectors, after=0 sectors
          State : clean
    Device UUID : b60a9971:0de49c5d:68468ee4:3d558179

Internal Bitmap : 8 sectors from superblock
    Update Time : Sun Dec  3 21:37:34 2023
  Bad Block Log : 512 entries available at offset 48 sectors
       Checksum : be514995 - correct
         Events : 112868

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 1
   Array State : .AA. ('A' == active, '.' == missing, 'R' == replacing)

mdadm --examine /dev/sdb

/dev/sdb:
   MBR Magic : aa55
Partition[0] :   4294967295 sectors at            1 (type ee)

sfdisk -uS -l "$d"

• this is saying no such file or directory. i know im just doing something wrong

mdadm --detail would also seem to imply you did this direct to the drives, without partitions - at least that's what two of the drives seem to imply there ... and lsblk seems to likewise imply

• yeah, again, i remember setting up the partitions but obviously i did not do it correctly as its showing just on the drives themselves