Subject: Storage
Manufacturer: Western Digital
Tagged: wdc, WD, Red Pro, red, hdd, 6tb, 4TB

Introduction and Specs

Introduction:

*** NOTE ***

In the preparation for this review, we noted abnormal behavior with the 6TB Red. After coordination with Western Digital, they replicated our results and will be issuing a firmware to correct the issue. We are publishing this piece as-is, with caveats added as appropriate. We will revisit this piece with an additional update once we have retested the 6TB Red on the updated firmware / configuration. More information / detail is available in our related news post on this matter.

*** END NOTE ***

Last year we covered the benefits of TLER enabled drives, and the potential for drive errors in a RAID can lead to the potential loss of entire arrays. Western Digital solved this problem by their introduction of the WD Red series. That series was since incrementally updated to include a 4TB capacity, and other Western Digital lines were also scaled up to 4TB capacities.

20140715-195152.jpg

This week the Red line was updated to include both 5TB and 6TB models, sporting 1.2TB per platter. Performance is expected to be slightly improved over the older / smaller capacities of the Red. The upgraded line will use an improved 'NASware 3.0' firmware, which makes improvements to Western Digital's software based vibration compensation. These improvements mean WD can now support up to 8 Reds in a single chassis (up from 5 with NASware 2.0).

Also announced was the new Red Pro line, available in capacities up to 4TB. The Red Pro is just as it sounds - a 'Pro' version of the Red. This model borrows more features from WD's enterprise line, making it very similar to an SE series HDD. Imagine a Red, but at 7200RPM and more aggressive seek times. The Red Pro also borrows the enterprise-grade 5-year warranty and is supported in chassis up to 16 bays, thanks to built-in hardware vibration compensation. When all is said and done, the Red Pro is basically a WD SE with firmware tweaked for NAS workloads.

As a recap of what can potentially happen if you have a large RAID with 'normal' consumer grade HDD's (and by consumer grade I mean those without any form of Time Limited Error Recovery, or TLER for short):

  • Array starts off operating as normal, but drive 3 has a bad sector that cropped up a few months back. This has gone unnoticed because the bad sector was part of a rarely accessed file.
  • During operation, drive 1 encounters a new bad sector.
  • Since drive 1 is a consumer drive it goes into a retry loop, repeatedly attempting to read and correct the bad sector.
  • The RAID controller exceeds its timeout threshold waiting on drive 1 and marks it offline.
  • Array is now in degraded status with drive 1 marked as failed.
  • User replaces drive 1. RAID controller initiates rebuild using parity data from the other drives.
  • During rebuild, RAID controller encounters the bad sector on drive 3.
  • Since drive 3 is a consumer drive it goes into a retry loop, repeatedly attempting to read and correct the bad sector.
  • The RAID controller exceeds its timeout threshold waiting on drive 3 and marks it offline.
  • Rebuild fails.
  • Blamo, your data is now (mostly) inaccessible.

I went into much further detail on this back in the intro to the WD 3TB Red piece, but the short of it is that you absolutely should use a HDD intended for RAID when building one.

Continue reading our review of the new WD 6TB Red and 4TB Red Pro!!

Western Digital launches 6TB Red and 4TB Red Pro - with a configuration issue

Subject: Storage | July 23, 2014 - 03:21 PM |
Tagged: western digital, wdc, WD, Red Pro, red, 6tb, 4TB

Western Digital has extended its Red line with 5 and 6TB models, sporting 1.2TB per platter. Performance is expected to be slightly improved over the older / smaller capacities of the Red. The upgraded line will use an improved 'NASware 3.0' firmware, which makes improvements to Western Digital's software based vibration compensation. These improvements mean WD can now support up to 8 Reds in a single chassis (up from 5 with NASware 2.0).

20140715-194643.jpg

Also announced was the new Red Pro line, available in capacities up to 4TB. The Red Pro is just as it sounds - a 'Pro' version of the Red. This model borrows more features from WD's enterprise line, making it very similar to an SE series HDD. Imagine a Red, but at 7200RPM and more aggressive seek times. The Red Pro also borrows the enterprise-grade 5-year warranty and is supported in chassis up to 16 bays, thanks to built-in hardware vibration compensation. When all is said and done, the Red Pro is basically a WD SE with firmware tweaked for NAS workloads.

We typically have our WD reviews post right at the NDA. On this piece, we opted to hold back as we've been working with Western Digital on some abnormal performance results we saw with the 6TB Red. Below are the results seen in Iometer. Note that the 6TB Red failed to demonstrate the expected 'ramp up' seen with other drives. HDDs normally show increased performance as Queue Depth increases. This is because the HDD controller is able to see multiple pending requests and optimize its access pattern. The more commands in the queue (higher QD), the more the HDD can optimize the pattern, and therefore the higher resulting IOPS seen.

iometer-ios-file.png

As you can see above, the 6TB Red appears to behave as if NCQ is disabled. Some might argue (in reviews that have already published) that the drive still performs well, but the plain truth of the matter is that a HDD effectively operating without NCQ removes the drives ability to scale when multiple commands are issued. Any test issuing more than one command simultaneously will see a lesser result as compared to a properly configured drive, so things like streaming multiple videos or several users actively simultaneously accessing a NAS will see a negative impact on performance.

The 4TB Red Pro did not demonstrate the issues noted above, and Western Digital has just issued this statement in response to our feedback. Here it is:

WD has learned that initial production units of WD Red 5* and 6 TB drives perform below our expectations in random-read benchmark tests when measured with specific testing software. We have found a configuration setting to be causing these particular test results, for which we are developing a firmware update to correct the configuration setting. In the intended application -- multi-drive NAS systems -- the drives have performed to our high expectations in WD’s labs and by our system partners; users will experience normal WD Red performance.

WD is committed to providing optimally performing storage products, designed for intended applications, and we will have a firmware update available through the WD Red Product Customer Service support line as it becomes available.

*Limited quantities of 5 TB have shipped with the earlier configuration setting.

We have decided to publish the full article covering both new drives, including the 6TB Red in its (currently shipping) misconfigured form. It will go live once I add the necessary verbiage explaining the misconfiguration seen on the 5TB and 6TB Red. Stay tuned for that piece later tonight (**EDIT** our review is now live **EDIT**), as well as a follow-on piece to be published as soon as we have the updated firmware from Western Digital.

Full press blast on the 6TB Red and 4TB Red Pro appears after the break.