Don’t RAID Western Digital Drives

It seems that ordinary Western Digital (WD) hard drives have an “advanced” feature that makes them unsuitable for either hardware or software RAID. Since I like to mirror the family's hard drives for security in the event of hard drive failure — we had one fail on my wife's machine last week so this is hardly paranoia — this is something I am glad I found before placing an order.


Western Digital manufactures desktop edition hard drives and RAID Edition hard drives. Each type of hard drive is designed to work specifically in either a desktop computer environment or on RAID controller.

If you install and use a desktop edition hard drive connected to a RAID controller, the drive may not work correctly unless jointly qualified by an enterprise OEM. This is caused by the normal error recovery procedure that a desktop edition hard drive uses.

When an error is found on a desktop edition hard drive, the drive will enter into a deep recovery cycle to attempt to repair the error, recover the data from the problematic area, and then reallocate a dedicated area to replace the problematic area. This process can take up to 2 minutes depending on the severity of the issue. Most RAID controllers allow a very short amount of time for a hard drive to recover from an error. If a hard drive takes too long to complete this process, the drive will be dropped from the RAID array. Most RAID controllers allow from 7 to 15 seconds for error recovery before dropping a hard drive from an array. Western Digital does not recommend installing desktop edition hard drives in an enterprise environment (on a RAID controller).

I think the box should have a warning sticker about this…

Meanwhile, back to the hunt for reliable, very quiet, low-heat-producing, mass storage.

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9 Responses to Don’t RAID Western Digital Drives

  1. Mel says:

    You might want to take a look at the Buffalo Linkstation Pro Duo. It’s a NAS that comes with two 500GB drives that can be configured to either RAID 0 or RAID 1. I installed this package about a week ago and have not had problems although we had to contact technical support to get it up and running.

    Tech support was excellent but we were on hold for a long time. The support agent had us reset the NAS, upgrade the firmware and then walked us through configuration and testing.

    More information available here:

  2. Joe says:

    I spent part of yesterday afternoon looking for a NAS to replace my netgear sc101. From my quick evaluation, it appears that in that end of the market, all of those devices are bad, and they all have problems. I can’t justify spending a grand for a home backup solution for a not too critical network. Maybe I’ll just build a home server using old parts.

  3. John Flood says:

    I bought a Buffalo Terastation (1TB) which has 4 250GB drives that can be put into any RAID configuration off eBay last year. It’s main use is to run music for the house, but it does backup as well. It runs continuously. It runs Linux and the ROM is easily flashable to make it receptive to running new software, eg, slimserver for Squeezebox.

    I also saw a Maxtor 750GB external drive (non-NAS) on sale for $200+ today.

  4. michael says:

    But is it quiet?

  5. Joe says:

    If the terastation is reliable, I can hide it in my basement (yes, I know, no basements in South Florida). The reviews I read yesterday questioned its reliability, and rated it no better than the netgear.

  6. Mel says:

    The Linkstation Pro Duo is quiet. I’m sitting next to it all day as I work and I’m not aware of any sounds. There probably is some hum, but I don’t notice it.

    LIke the Terrastation, this NAS runs Linux. The technician said that you could remove the drive and recover the files in Windows using a utility. Other NAS like Netgear use a proprietary format, meaning that if the NAS goes so does your data.

  7. John Flood says:

    I’ve been running my Terastation for a year now with no problems. Yes, it’s quiet. But the nice thing is that because it’s a NAS you don’t need to have it near where you work or your computer. Now depending on whether you’ve got cat 5 cabling running through your house–which most of us haven’t–then the alternative is to use network power mains plugs that let you run your ethernet through the mains. It’s easy to control because I can telnet into it.

  8. nic says:

    I have 5 Western Digital drives in two md software arrays, a raid 1 and a raid 5. I had a lot of trouble with one of the drives in my Raid 5 over Christmas, when it was constantly being dropped from my array. The linked answer provides an explanation for the strange behaviour.

    I strongly believe that there should be more explicit disclosure of what is a fairly serious drive limitation (or feature). I certainly would not have bought these drives had I known that they were not suitable for use in a raid array.

  9. Joe says:

    Michael, John:
    I changed my mind and bought a Terastation Live 1TB. I brought it home, powered it up, and transferred my files to it from my Netgear drives. I left the Terastation in Raid 5 (the default configuration), which yields almost 700 GB of space. After a week, I had finished transferring all of my data (I took my time to make sure that I didn’t miss anything). On the 16th of February, I shut down the Terastation to move it 5 feet to a different location, onto the table behind my monitor. I turned on the Terastation, and it went into safe mode because it could not read the array info. I called Buffalo, and got to technical support in 5 minutes. The technician walked me through the procedure to flash new firmware into the device. The machine now seems to be ok. Michael, it is very quiet, much quieter than the Netgears, and a lot quieter than my 4-year old Pentium 4 (which is next on the replacement list). Ten years ago, I pulled cat 5 cable through the house, when my wife and daughter were away. They didn’t notice the cable when they came back, so I guess I did a good job. Anyway, at $650.00 or so, the Terastation is worth a look. I live in Northeast DC, near St. Ann’s Infant Home. We lose power here occasionally, so I plugged the Terastation into my battery back-up.

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