WD EARS in raid 5 with EADS?

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sonofander

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So I have an existing raid 5 array on an areca 1230 with 8 2tb WD EADS drives up and running. My array is full and I'm looking to add a new drive. Seems everyone is selling these damn ears drives now instead of the eads ones. Will I be alright dropping one in my array? Should I expect problems? Anything I need to know going in?

Thanks
 
They do not support TLER; do your current EADS support TLER? The older sold EADS disks did support TLER; recent sold ones do not. That means you have to look for expensive TLER-capable versions which are sometimes twice the price; even though it's a simple firmware switch (on/off). You would need TLER disks to prevent your hardware RAID from splitting up, throwing disks out and that kind of unwelcome behavior.

The EARS drives also have 4K sectors which may be very bad on RAID5 in some cases. Make sure you align your partitions well if you are about to take this option. There have also been reported performance issues with ZFS if you will ever take that route.

Other than that, the EARS are cheap and more reliable than EADS due to less bad sectors caused by bigger ECC pools on their 4k sectors; while EADS uses normal 512 byte sectors and standard ECC pools, and thus might see more bad sectors during its lifetime.
 
I have some eads drives that I picked up when they first came out, so I'm sure they have TLER. Is there anyway of disabling this on my raid card so that I can avoid this problem?

As far as sector size, running the WD partition utility prior to adding them to my array should take care of that?
 
sonofander said:
I have some eads drives that I picked up when they first came out, so I'm sure they have TLER. Is there anyway of disabling this on my raid card so that I can avoid this problem?

As far as sector size, running the WD partition utility prior to adding them to my array should take care of that?
Click to expand...

Reading this I understand you did not enable TLER on your 8 current drives? I'm supprised, aren't you experiencing problems like disks falling of your raidset?
I own a 24-port areca controller and back in the day when I did not enable TLER on my WD20EADS drives they were dropping out of the raidset on a daily base...

I'd advise against adding WD20EARS to your raidset. Also be aware when you find WD20EADS drives. I recently got 4 of those with production date july 2010 and I could not enable TLER on them (thus im not adding them to my array)

[EDIT] P.S. You can't influence this setting with your areca controller [/EDIT]
 
You are correct, I never enabled TLER on any of the drives in my existing array. I haven't had any consistent problems with kicked drives. Maybe one every few months or so, but adding it right back in when that does hasn't been a problem. TBH I didn't even know about TLER till now...

So given that I don't have TLER enabled on any of my GP drives ATM, what should I do? Sounds like going forward, I won't be able to find TLER capable GP drives anyway, so pulling the array and flashing TLER on doesn't seem to make much sense, does it?

I have a secondary 4 drive raid 5 array that I could break and use those for the primary... I'm assuming that all my current drives are TLER capable. Is there a way to find out? Can I enable it drive by drive without breaking my primary array? And I guess most importantly, how do I go about getting the utility to enable TLER?

TIA
 
Oh, and if I end up creating a new array with EARS drives, do I need to use the WD formatting tool, or will they be ok as is on the Areca controller?

And why isn't there a setting on my controller to change the timeout threshold? Damn...
 
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