Network-attached storage

A nice compact 4TB network disk with ECC RAM and an ESATA port. Fairly quiet and cool, only 53W when idling.

• Disk: 2x Seagate Barracuda LP5900.12, 2TB (ST32000542AS).
• Case: Antec NSK 1380, bundled with a 350W power supply. 20cm x 27cm x 34cm.
• Motherboard: Asus M4A785TD-M EVO — AM3 socket, 5xSATA, 1xESATA 1xPATA, 12xUSB, 1xFirewire, 1xGigabit-ethernet, 1xDSUB/DVI/HDMI, etc. Supports ECC memory scrubbing.
  Form factor: µATX.
  Warning: This motherboard is extremely picky about RAM. Read here about my troubles getting it to work in another box.
• CPU: Athlon II X2 240e — two 2.8GHz cores, 2x128kB L1 cache, 2x1MB L2 cache. No L3 cache. Thermal design 45W.
• RAM: 1x 2GB Kingston 1333MHz ECC (KVR1333D3E9S/2G).
• Optical drive: Asus DVD-E616A, an old DVD-ROM IDE drive transplanted from another box.

Configuration

OpenSUSE 11.2, non-desktop server install. 500GB on each disk used for RAID-1 partitions, using the Linux software-raid driver. The remaining space is non-mirrored. But instead of creating a single huge 3TB file-system using RAID-0 striping, I decided to put a separate file-system on each physical partition. This makes a single disk failure less catastrophic for the non-mirrored data. It also makes it easier to move around individual disks without backing up and restoring everything.

Clients mount everything via one single mount point. The server uses Linux "bind" mounts to glue the three file-systems together (500GB + 1.5TB + 1.5TB). Each file system has to be NFS-exported separately, or rather the "bind" mount-points are exported. The clients can then access all three file-systems by traversing the directories in its NFS mount. It's still not a single 3.5TB volume of course. Space is still allocated from different partitions depending on which directory tree you are writing to.