Storage Architecture

Builds a reliable RAID5 storage array with an ext4 filesystem tuned for high throughput. It uses five drives (~36 TiB usable) with a 512K chunk size, proper stripe alignment, and an internal bitmap to speed up rebuilds. The filesystem is mounted with low‑overhead options to keep performance strong on small‑board hardware while ensuring consistent, predictable behavior.

RAID layer (mdadm)

• Array: /dev/md0
• Level: raid5
• Devices: 5 (sda–sde)
• Array size: 36.38 TiB (40 TB raw)
• Chunk size: 512K
• Layout: left-symmetric
• Bitmap: internal (faster rebuilds)
• Creation command (reconstructed):

bash

sudo mdadm --create /dev/md0 \
  --level=5 \
  --raid-devices=5 \
  --chunk=512 \
  --bitmap=internal \
  /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde

Filesystem and mount

• Filesystem: ext4 (block size 4096)
• Stripe alignment: stripe=384 (aligned to RAID geometry)
• Mount point: /media/plutus
• fstab entry:

Code

UUID=9ce92a73-c4d2-4693-bbc1-68bc21c5d184 /media/plutus ext4 defaults,noatime,nofail 0 2

• Mount options observed: rw,noatime,stripe=384

Rationale

• ext4 chosen for low CPU overhead on SBCs and mature tooling.
• 512K chunk and stripe alignment tuned for large sequential media workloads.
• Internal bitmap reduces rebuild time and risk on intermittent IO.