Wednesday, September 16, 2015

Cracking open some WD Elements to use the hard drive within

Unfortunately my 3TB Seagate Barracuda (Z1F0DS2F), which I bought in May 2012, died on me randomly. My NAS immediately reports when hard drives start getting bad sectors and should be replaced. But this hard drive died on the spot! I had no opportunity to recover my data. The moment I would try to mount the drive, it would just disappear on me. I had lost my data. Luckily it wasn't data that can't be replaced, but it still sucked.

The Plan

I was always too cheap to do RAID, but this was the last time I wanted to lose data from a dying drive. I already had one 5TB drive installed in my NAS, so I wanted to buy two more 5TB drives in order to have 10TB of space with 5TB of redundancy. Meaning that one hard drive can die and I do not lose any data. I used the Synology RAID calculator to determine this. The problem was that I had over 2TB of data already stored on my 5TB drive. In order to do RAID5, you need to reformat from scratch and use a minimum of 3 drives. I had nowhere else to put the data temporarily! Luckily, Synology has something called SHR.

Synology Hybrid RAID (SHR) is like your traditional RAID, but it provides the opportunity to expand volumes without losing data. So what I could do is create the SHR with the two 5TB drives, move the data from the third drive, and then finally include the drive to the SHR volume.

Searching around online, I found a good deal for some 5TB WD Elements Desktop external drives for $130 each. Users have reported that when opening them up, they found Western Digital (WD) RED drives in them. WD RED drives are ideal for storage, specifically NAS devices. But the drives are not cheap, being closer to $200 each. On the other hand, you void the warranty when ripping open these cheaper external drives. My 3TB drive that died was cracked out of an external, and checking the drive warranty with Seagate shows that it cannot be RMA'd as-is. And of course I had thrown away the casing to try and put it back together. Anyways, I decided to take the gamble and purchase the two 5TB WD Elements in hopes of getting lucky.

The Luck (or lack of)

Unfortunately, lady luck left me dry. They were two WD Green drives, which are part of the "power efficient" series. If you use these drives as-is, they will not last very long before they fail. They are very aggressive in terms of parking the head of the drive in order to save power. This causes excessive wear on the drive when using it for storage and constantly accessing it for reads/writes on a NAS. I had to use idle3-tools on linux in order to disable this. Western Digital provides this for Windows users directly, called wdidle3.

After "fixing" the drives for NAS usage, I proceeded with my theory and formatted them into an SHR volume. I then transferred the data from the third drive and then added the drive into the volume with success. It actually took about two days in order to accomplish this. But now I have 9TB of usable storage, which should last me a very long time without having to worry about losing data from a dead drive.

Reusing the shell left behind

Since I took out the drives to use internally, maybe I could still use the WD case for other drives? Well, it isn't possible. Unless you will be replacing it with different 5TB drive, which I wouldn't see the point, it won't work. The 5TB disk size is hard coded into the controller. No matter what size disk you put in it, the OS will always read it as being a 5TB drive. And two things will happen, either the OS will correctly stop and tell you that it cannot format/use the drive or you will lose data. I just ended up throwing mine away.


  1. I'm not sure I agree about the short lifespans of WD Green drives. I've got five of them, each with about 58,044 hours (6.6 years) of power-on time (without running the idle3-tools you mention), and only one of them is beginning to remap bad sectors (5 so far).

  2. Weird that the case is "hard coded" for 5tb. I haven't seen that before, and I've opened up plenty in my time.
    About to see about the 8TB one, as thats the best bang per buck locally.

    I have seen some evil stuff though where the drive is actually usb. i.e. they've made a special board drive revision which has usb instead of sata, so they deliberately stop you from re-using the drive as intended.


  3. TLDR: Kids, don't do this.

    There is much wrong with this article.
    If you're worried about losing data, NOT constant uptime, you don't want a regular RAID5 and in any case you don't want a proprietary SHR that depends on the storage box.

    At MOST you want a standard RAID 5 but really, just RAID1 where you can pull either drive to recover all data on any SATA controller. Yes you will lose some capacity but again, your stated concern was data loss. If you're not going to have an offline backup (which takes more HDDs anyway) then a proprietary RAID5 really isn't the way to go!

    If you're "constantly" accessing the HDD on a NAS, an aggressive sleep timeout shouldn't matter. Normally aggressive only means 10 minutes or so, which should still not cause undo wear within the otherwise viable lifespan of the HDD. As with avoiding proprietary RAID5, if you intend for this to be a way to avoid data loss, you don't want to run the drives for 4+ years hoping they live as long as possible by avoiding head parking.

    In all likelihood there is no hard coding to make the USB bridge board work only with 5TB. That would make no sense at all. If WD were to implement something it would at least be mating to the particular HDD, but instead what seems likely is you had first plugged the drive in, inside the enclosure, and the OS assigned a hardware ID to it as a 5TB volume so you'd need to wipe out that hardware ID or at least whichever mechanism that particular OS needs to relearn the partition structure, THEN format it.

    Again you throw away perfectly good external housings. Do you live in a shoe box? Keep the parts to the things you own until you are done with them. Senselessly adding to landfills to save your self small money is terrible, but then you have spare time to write about it. How about if the spare time was spend earning more money for the WD Reds as spare drives and getting enough to do a RAID1 AND have an offline backup? That kills all birds with one stone.