DIY external RAID5 array

Here is a home project I did almost a year ago and I’m very pleased with it.  I wanted to create an external drive array.  1TB drives was my choice.  Initially I built this as a 3 drive array, and within a few weeks I grew it to a 4 drive array.

First I purchased the enclosure for about $19.  The enclosure is basically just a metal frame meant to hold up to 5 drives.  It includes a fan, although the fan is not really needed, because the ambient air is enough to cool the drives.  It has a power switch and an ATX connector. It accepts an ATX power supply to power the drives and fan.


Drive enclosure front view


Drive enclosure side view

The cool thing about using SATA drives is that they use a SCSI protocol and you can use them with a SAS cable.  Rather than have four individual eSATA cables connect each drive, I found a single SAS cable that fans out to four SATA connectors.

SAS fan out cable

SAS to SATA "fanout" cable

The cable in the picture is a short version.  My cable is 1 meter in length.  I found the cable online for about $55.  The SAS cable connects to my SCSI controller card.  It’s an IBM LSI type PCI express controller.  You should be able to find them on Ebay.  The controller card is already supported by linux.

$ sudo lspci -nn

02:00.0 SCSI storage controller [0100]: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS [1000:0058] (rev 08)

I’m using software raid5 built into the linux kernel, because I’m want maximum compatibility.  Also, my controller card doesn’t do RAID5.   I’m not overly concerned about speed.  This is intended to be a fault tolerant file server where I will keep music, photos, videos, backup images, and other important data.

Here are photos of the finished array.

Enclosure with power supply

Drive Enclosure with ATX power supply atop

I used thick double faced tape to mount the ATX power supply on top of the drive array.  The total height is 11 inches.  A black power supply would have been a better choice, but I already had this one laying around and ready for use.


A view from the other side showing drive fan

The picture above is a view from the other side.  The extra unused molex connectors are tucked away.  I debated, removing them by opening up the power supply and cutting them away, but ultimately I left them.  The drive fan is remarkably silent.  It could probably be removed without as there is enough ambient air to cool the drives.


A view of the drive array in normal use

And finally a night time shot of the drive array in use.  The led lighted power supply is glowing in the night.  The camera lens adds to that affect.  The actual glow is less dramatic.


A view of the drive array at night

The four drive array gives me a total of 2.7TB of fault tolerant storage.  It is currently mounted on my Fedora 12 server.  Look for more details to come in a part 2 of this series where I show how to create the RAID array and how to grow it.