RE WD20EARS & LLC

[jrw]

I want to upgrade my NV+ from 1TB to 2TB drives & am having difficulty deciding which drives to use from the limted list of approved drives. Some are just too expensive, others, like the Seagate's, appear to have drive failure problems. There are no Samsung drives unfortunately (my 1TB drives have been v reliable).

I was considering the WD20EARS but I read about an issue regarding LLC that may mean the drive life is compromised - can someone please tell me if these drives are reliable and can be used without having to modify the firmware?

Netgear, please consider adding more drives to your list - when 2TB drives can be bought for about £50 it seems odd that half your approved drives cost £100+!

Thanks

[alexofindy]

No clear answer here, as best I can tell. Western Digital "green" drives, which include the model you mention as well as their 3 TB WD30EZRS drives have a "feature" that parks the drive heads and turns off some of the electronics, to reduce power consumption. Each time the heads are parked, the LCC increases; the LCC count on a drive can be read by looking at the SMART status (on the health page of a Readynas). I believe LCC stands for "load cycle count" but I don't know exactly what that means.

When I asked WD support about this, I was told not to worry, the drives are designed to function with high LCC's, and this shouldn't cause the drive to fail. But there was more. The drives had been tested with an LCC of up to one million, but apparently not beyond this. Further, the WD green drives are designed for a desktop PC installation, NOT for a RAID system like a readynas. Western Digital would offer no guarantees when a WD green drive was installed in a RAID-based NAS.

I bought an Ultra 6 plus, and installed 3 WD30EZRS drives. And, I watched the LCC count. After 3 months it was at 250,000. So, it would hit the million mark in a year. I concluded this was not good.

There is a way to stop the LCC from increasing, which is well described in this forum and elsewhere: run a WD provided utility called WDIDLE3, which will reset the idle timer setting on the drive. Once this is done, the LCC will basically stop increasing (and I would guess power consumption on the drive will increase)

WDIDLE3 is easy to use, instructions are elsewhere in this forum, but it must be run by installing the drive in a PC with a SATA interface that can boot DOS (or freedos) from a CD or USB.

Once the LCC on my drives hit 250,000 I ran WDIDLE3 on them.

Now, the WD drives are on the Readynas official hardware compatibility list. So, netgear is treating them like they are OK. But the LCC issue is worrisome, and most forum users who have voiced an opinion run WDIDLE3.

My recommendation: either run WDIDLE3 on WD green drives, or use a different brand of drive (when I purchased my system, the WD's were the only 3 TB drives I could get my hands on). There are several brands of 2TB and 3TB drives on the compatibility list that don't have the LCC issue.

[jrw]

Many thanks for the informative update

[tpg]

I appreciate that data provided, and maybe it was a "slip of the tongue", but I've got to ask ... you claim that, for the NV+ ...
"There are several brands of 2TB and 3TB drives on the compatibility list
that don't have the LCC issue."

But in looking at the compatibility list, I do not find any 3 TB drives ... I'm at 4x1TB today, and if I'm going to upgrade, I'm not going to buy enough to just double my capacity ... I'd rather shoot high. So, is there a 3 TB drive on the list?

Again, not being a complainer ... more of hoping I've overlooked something.

tpg

[alexofindy]

Sorry if I wasn't clear on that.

The NV+ and other sparc-based readynas units can't use 3 TB drives, and probably never will. Development of Linux has basically stopped for sparc-based computers, including sparc-based Readynas systems such as the NV+. 3 TB is not supported by the old MBR based disk partitioning scheme, which is the only partitioning scheme supported by the sparc Linux distro used by Netgear. 3 TB requires a GUID partitoning scheme which is supported on x86 Linux and x86 readynas systems. So, you can't go above 2 TB on an NV+, but you can on all recent vintage readynas systems, which have Intel (x86) processors.

I have two readynas units, an NV+ (with two 500 GB drives and two 2 TB drives) as well as a Ultra 6 + (with three 3 TB WD drives).

The comments I made about WD drives hold for both the 2TB and the 3TB green WD drives, with the models mentioned.

[Knakker]

Thanks again @alexofindy!
Hope this will help preventing errors using the Power Timer feature, since I have 'disk failures' for a while now (since using this feature).