"standard" drives not recommended for RAID?

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runLoganrun

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Jul 4, 2005
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I have a short stack of WD1001FALS hard drives, and was planning on getting a couple more, so i could start a raid 5 array. I was just reading on another forum where someone states that both WD and Seagate say they don't recommend their desktop drives for raid. This is news to me, can anyone comment?

thanks,
rlr
 
Although i haven't had any personal experience i've done some reading about this issue as I'm researching for my next system. Standard drives can have a tendency to get dropped by some raid controllers for being unresponsive when they're in deep recovery.
It seems with WD you just need to enable TLER with their utility

this thread should be very helpful
http://www.hardforum.com/showthread.php?t=1285254
 
I use WD drives in my RAID setups. No problems with TLER enabled. Had a few before I enabled it. Atleast we have the tool. :)
 
I can confirm this with the new 1.5TB WD GP drives. TLER does not work and just errors out.
 
That post got my hopes up but by the time I read through it to then end I was just as frustrated.

I'd love to use some 1.5TB WD GP drives in R5, I don't suppose we can flash an old firmware onto them so that the WDTLER tool will work. Or maybe a retailer that has old stock? Wishful thinking I'm sure.
 
No the RE drives are not identical to the consumer drives sans firmware.

edit: This sums it up pretty well:

Here's a list of the common differences between Desktop drives and Enterprise disks: http://episteme.arstechnica.com/eve/forums/a/tpc/f/24609792/m/424004602041?r=172008702041#172008702041

* Warranty - The desktop drives usually have a 3-year (or less) warranty, while the Enterprise drives usually have a 5-year warranty (IIRC, some of the Samsung drives have a 7-year warranty).
* MTTF/MTBF - This calculated value is an estimate of the number of hours until the drive fails, and is only valid for the warranty period. For Enterprise drives, it's usually higher than for their Desktop counterparts.
* Error Recovery - This is called various things by various manufacturers (TLER, ERC, CCTL). In a Desktop drive, the goal is to do everything possible to recover the data. In an Enterprise, the goal is to ALWAYS
return SOMETHING within the timeout period; if the data can't be recovered within that time, let the RAID controller reconstruct it. Wikipedia article.
* Bit Error Rate - This is a statistical measure of how often an error (either recoverable or unrecoverable) will occur. The rate for Enterprise drives is usually lower than for Desktop drives.
* Vibration resistance - When several disks are in a single chassis, the vibration from one or more of the drives can effect the others. Some Enterprise drives have firmware (with sensors?) that specifically reduces
the effect of this vibration on the error rate. On those drives where this is done, it can sometimes be seen as a difference in the vibration specs of the drive.
* Target market segment - Enterprise drives are designed for 5x9 operation with light use, while Enterprise drives are designed for 7x24 operation with heavy use. I believe this effects the motor & voice-coil
drive electronics, possibly the overall disk heatsink capabilities, and possibly the operating temperature range of the drive.
* Request Queuing - Enterprise drives usually have improved queuing algorithms for I/O requests. This gives more IOPS as the load increases (something you're not likely to see in a lightly loaded Desktop usage).
 
Last edited:
Old Hippie said:
Ya, but you might want to be a little careful with it on the newer drives.....

WD phone support confirmed that new disks cannot have the TLER setting changed, i.e. RE disks are only suitable for RAID arrays and Caviar are only suitable for non-RAID use. WD also say that using the WDTLER.EXE tool on newer drives can damage the firmware and make the disk unusable.

As usual, YMMV.
Click to expand...

That's a bummer. So does that mean I can't use my WD1001FALS desktop drives for raid 5? How less safe is it, or is it just a bad idea in general? I have 4 or 5 of these, was planning on getting 3 additional to start array with, then feeding/expanding with drives I currently have.

thanks,
rlr
 
Provided you can change your "old" ones to the correct TLER setting and get a few more used, then you should absolutely go ahead.
Using new non-TLER-modifyable drives would just be a really bad thing in general, unless you have good backups and are willing to restore. (Which I bet you aren't.)
 
Yonzie said:
Provided you can change your "old" ones to the correct TLER setting and get a few more used, then you should absolutely go ahead.
Using new non-TLER-modifyable drives would just be a really bad thing in general, unless you have good backups and are willing to restore. (Which I bet you aren't.)
Click to expand...

How do I tell if that setting will work on these drives? It's in lifeguard tools? most of them are less than 2 years old.

thx
 
runLoganrun said:
How do I tell if that setting will work on these drives? It's in lifeguard tools? most of them are less than 2 years old.

thx
Click to expand...

AFAIK you're just gonna hafta try the TLER tool and see if it will let ya change the setting.
 
guys, if u have wd 1tb black drives with the dcm thingy ending in '2ab' or '2cb" then u can enable tler on them. The manufactuerer date does not matter.
 
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