Checking for TLER, ERC, etc. support on a drive

jgreco

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RAID or small NAS both cases suggests that more than 1 HDD will be used. When more that 1 HDD is used then redundancy should be assumed. Therefore SCT should be enabled.

NAS doesn't suggest that more than one HDD will be used. There are lots of single drive NAS units. If you want to blow out your irony sensor,

http://www.seagate.com/support/exte...ork-storage/business-storage-1-bay-nas/#specs

Business storage? 1 bay? Are they kidding?

And then you notice it's made by Seagate ... a company that ought to have a vested interest in convincing businesses that RAID1 or better is mandatory for data storage.
 

cyberjock

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WD 8.0 TB WD80EZZX (Pulled from a mybook - It is an HGST drive - 5400rpm He8??)
TLER can be enabled, but does not persist after shutdown

This post has a nice script for enabling TLER on all drives at boot:
https://forums.freenas.org/index.ph...-tler-is-always-enabled-on-your-drives.43494/

This may mean that TLER won't actually function. Many drives only "enable" TLER on poweron and power cycle (initialization of the hard drive). So while it may "look" enabled, it may not actually be "enabled and functional" or however you'd describe it.
 

rogerh

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This may mean that TLER won't actually function. Many drives only "enable" TLER on poweron and power cycle (initialization of the hard drive). So while it may "look" enabled, it may not actually be "enabled and functional" or however you'd describe it.
OTOH some drives seem to lose the setting when they reboot. So all drives should work on the second reboot. Except perhaps some that appear to accept the setting but only actually use it in some demi-monde between alive and dead
 

cyberjock

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OTOH some drives seem to lose the setting when they reboot. So all drives should work on the second reboot. Except perhaps some that appear to accept the setting but only actually use it in some demi-monde between alive and dead

Sure. So how do you *prove* for 100% certainty TLER is even working? For all we know, there's a bug and TLER doesn't work at all!

We can obviously do lots and lots of discussion about who is right or not. Personally, if a drive isn't sold as being able to support TLER, I'd never, ever buy one expecting it would work, and therefore would never find a need to try to use this drive because of its "exceptional featureset". :P

I just don't see how this is a good idea for any situation. I prefer to leave well enough alone. The more you do things that nobody else does, or do things that aren't officially supported, the more likely you are to run into some nasty problem that could be serious. Is it worth your data to risk such an incident? I'll take the very conservative side and say "no fscking way".
 

jgreco

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Sure. So how do you *prove* for 100% certainty TLER is even working?

I can't *prove* for 100% certainty that you're real. Are you for real?

For all we know, there's a bug and TLER doesn't work at all!

Sure. But in other cases, we're lucky enough to be able to figure it out.
 

cyberjock

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Spearfoot

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All of you are a figment of my imagination...
 

pclausen

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So has anyone rolled the dice on setting up a system using the WD80EZZX drives pulled from the WB MyBook? These are going for around $200 on eBay right now. Seems like a heck of a deal for 8TB drives if they will play nice with FreeNAS.

I have 14 6TB WD Reds and 12 4TB Seagate ST4000DM00. Was thinking about selling them all and picking up 20 of these 8TB MyBooks with the proceeds. I would then setup 2 vdevs, each configured with 10 x 8TB in raidz2 for a nice 160 TB gross volume.

Just curious if the TLER function has been confirmed to work on these yet or not.
 

Ericloewe

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@jgreco bought a few and is testing them, but I think his used HGST branded drives?
 

pclausen

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My understanding is that:

WD80EZZX = HGST 8TB 7200RPM
WD80EFZX = WD 8TB RED 5400RPM

Looking forward to hearing @jgreco report on his findings.
 
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jgreco

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Sorry, nothin' yet. I've got a client on fire and I've had to put all hardware playing on hold. :-/
 

PhilipS

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I am using two WD80EZZX drives pulled from MyBooks. They are white labeled WD drives, but the case is identical to HGST drives and they have no vent holes, so it is possible that they are helium drives. They run at 5400 rpm. They do not have TLER enabled. You can turn TLER on, but it turns off when they are power cycled. As cyberjock says, no way to know if TLER really works until you have one with damaged blocks.
 
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As cyberjock says, no way to know if TLER really works until you have one with damaged blocks.

I don't understand why that would be ? If you can set it up with command on each drive, despite the fact it won't stay after power cycle, why you would think it wont work ?
 

Ericloewe

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I don't understand why that would be ? If you can set it up with command on each drive, despite the fact it won't stay after power cycle, why you would think it wont work ?
Because you have no idea what goes on in the firmware.

So you can either take the drive's report at face value or not trust it until validated.
 
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Because you have no idea what goes on in the firmware.

So you can either take the drive's report at face value or not trust it until validated.

Why would the drive lie ? If they(manufacture) don't wont you to be able to change the SCT Error Recovery Control value, wouldn't just say it's not supported. Are you saying the drive will accept the new value, show it has been changed, but don't actually comply with it ?
 

jgreco

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Why would the drive lie ? If they(manufacture) don't wont you to be able to change the SCT Error Recovery Control value, wouldn't just say it's not supported.

Because they don't expect anyone to be talking to the drive like that, and the fewer changes you make to the firmware when customizing variants of a drive, the better.

Are you saying the drive will accept the new value, show it has been changed, but don't actually comply with it ?

Absolutely he is saying that. I am too. That is exactly what this thread is about, dude.
 
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Wow ! So is there a point of trying to change with the command like: smartctl -l scterc,80,80 /dev/adaX ?
 

jgreco

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Wow ! So is there a point of trying to change with the command like: smartctl -l scterc,80,80 /dev/adaX ?

Of course there is. It works for some drives. If you do not try to change it, then it's guaranteed that it won't be changed on ANY drives.
 

pclausen

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So let's say TLER is NOT supported on these My Book 8TB drives and lets say I got 20 of them configured as 2 raidz2 vdevs with a net capacity of 128TB.

Let's assume I'm at 75% capacity and get a read error on one of the drives.

If TLER was working, after a short period of time (i.e. 7 seconds) that block would be marked bad and the data on it would be written to a spare block on the same drive from parity on the other drives, right?

So with TLER not working, ZFS would patiently wait for the read request to complete, right? But eventually it would give up and then what happens? If all I'm storing is static media that doesn't ever change (only new material is being added at a steady trickle), how big a deal is it if TLER does not work?
 
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