WDC Black in Raid 5

[davidst99]

Hi, is it ok to run three 4TB WDC Blacks in RAID 5 or should I return them get NAS drives. I plan to put them in my desktop. Thanks.

David

 

[dave_the_nerd]

It's fine.

 

[lehtv]

Based on a quick google search found this OCN post which says

So there you have it. Straight from the horse's mouth, WD Blacks ARE supported for RAID. Not any type, and for 4 drive setups or running enterprise type RAIDS like 10, 5, or others, you will need the drives designed for that. But for two drive configurations running RAID1 and RAID0, these drives have full support from WD.

I would get 3 x WD Red (or Red Pro) 4TB ... * edit * scratch that. The key thing here is that WD Black lacks TLER which you'll want to improve reliability in RAID, and while WD Red does have TLER, that's still not the optimal drive for RAID 5. More googling reveals:

WD Red drives are WD Green drives with TLER added, nothing more. They are aimed purely at small consumer usage, not for normal business RAID usage. The issues with parity rebuild failures due to URE (the key issues with RAID 5, but far from its only one) are not addressed by any consumer-range drive, WD Green being no exception and therefore Red not being an exception. TLER simply prevents the drives from unnecessarily dropping out of the array, not from failing to rebuild. So WD Red are perfect for low performance, low cost RAID 10 and, in smaller arrays, RAID 6 (in really large RAID 6 they are still too risky to use because of the URE issue.)

WD's enterprise drives that "could be" used in RAID 5 are the RE4 line which have the TLER of the Red drives, the URE rating of enterprise SAS drives, the spindle speed of Black drives and other advancements like bigger cache and CPU to boost performance over any other WD SATA drive.

The issue when you get a drive like the RE4 for RAID 5 is that RAID 5 remains slow (as all parity does) and risky for other reasons (drive failure rates, DAC, long rebuild times meaning loss of availability, etc.) but gets so expensive that RAID 6 and RAID 10 still beat it when actual dollars are applied. So RAID 5 is always ruled out, in every scenario, due to a large combination of factors.

So, no, Red does nothing for RAID 5.

Based on this, RE4 drives would be optimal, but they only go up to 2TB per drive. That is, if you really want to do RAID 5.

 

[davidst99]

Based on a quick google search found this OCN post which says


I would get 3 x WD Red (or Red Pro) 4TB. Red Pro is 7200RPM and with 5 year warranty, just like WD Black. If it's no problem to return the Blacks and wait for new Reds, no reason not to... WD Red is designed precisely for RAID environments, WD Black isn't.

Thanks for the advice. I'll get the Red drives.

 

[lehtv]

Sorry, I edited the post. :X

 

[Essence_of_War]

Hi, is it ok to run three 4TB WDC Blacks in RAID 5 or should I return them get NAS drives. I plan to put them in my desktop. Thanks.

David

Are you doing software RAID, hardware RAID, or fake/motherboard RAID?

For software raid, lack of TLER shouldn't matter. For the others, it might be worth switching to Red.

 

[Railgun]

I don't know the specific model, but I've been running four 2TB blacks in 5 for a while. It's fine. This is on an Areca 1880i.

 

[Cerb]

Hi, is it ok to run three 4TB WDC Blacks in RAID 5 or should I return them get NAS drives. I plan to put them in my desktop. Thanks.

David

Depends on the RAID. The core problem with HW RAID controllers has been freaking out if a drive takes too long to respond, and the HDD companies using that to their advantage, by hardcoding which behavior a drive will have on a read error (stop after a few seconds, or keep trying). For software RAID or Intel's semi-FakeRAID, it should be fine even in RAID 5 (as far as any desktop RAID 5 can be, anyway).

 

[Mighty_Miro_WD]

Hi there,

The WD Black is a very good drive but it was designed mostly for gaming and other demanding apps. For a RAID – I would suggest you to check some drives that were specifically designed for RAID environment, and have the RAID specific built-in features (like TLER – helps the drive recover faster in case of read/write error and the drive doesn’t drop off the RAID) that the other hard drives don’t have. Such drives for instance are WD Red which is tuned and optimized for 24/7 performance, RAID arrays and up to 8-bay NAS systems:

http://products.wdc.com/support/kb.ashx?id=0uExwR

However, if you already own the three Black drives they should work just about fine although they are meant for stand-alone drives.

Hope this helps.

Cheers!