Home Server Questions - lots of questions....

[LIGISTX]

Well, from a quick google search and ebay comparison, it looks like a VERY solid choice would be HMS5C4040ALE640, and ebay has them for 100 bucks!!! WHAT.

It does look like they only have 1 year warranty though...?

 

[gpsguy]

It appears that you should be able to look at the results - http://lmgtfy.com/?q=open+media+vault+smart+testing

The reason I suggest looking at them now is that you seem to be basing your buying decisions thinking they are usable.

Open media vault. There may be, but in the webui is doesn't give much at all.

 

[Mirfster]

Who do you buy from..? I guess a *slightly* used enterprise grade drive is actually more reliable than a new consumer grade drive.

Varies... I do take my time and watch eBay a lot. I am a Hardware Addict. :)

 

[Bidule0hm]

By WD you mean your red's I assume? Still no answer on the viability of blues.

Yes, I can only speak about what I've tested and I never tested WD blue ones so...

 

[LIGISTX]

Ok. Well. This "which drive to buy" game is not an easy one!

I have narrowed it down to 2 options. First, the HMS5C4040ALE640 (HGST MagaScale 4TB Coolspin) which has a VERY VERY low fail rate on backblaze, sub 1%, and I can get them for 99 bucks, or Seagate ST4000DM000 which have a 3.06% fail rate and are 111 bucks from Amazon Prime.

The seagate is the most used drive by backblaze that I can tell, but I think that was only because they can't buy the HGST in the quantity they would want them in.

Any advice or input here would be amazing. The HGST seems to be an enterprise level device, where the Seagate is just a solid performing consumer drive which affords it a 2 year warranty vs the HGST 1 year warranty.

 

[Mirfster]

Well, from a quick google search and ebay comparison, it looks like a VERY solid choice would be HMS5C4040ALE640

I only run HGST UltraStar Models; so I can't really speak on that particular model. For the record the 4TB HGST SAS Drives I recently purchased are "HUS724040ALS640". Which are technically Nearline-SAS Drives. I struck a deal with the Seller since I bought 13. Think the total with shipping ended up being ~ $1,800.00; so it was like $135.00/Each.

Ok. Well. This "which drive to buy" game is not an easy one!

Hard Drives are one of the major expenses and it would be prudent to take your time.

 

[Robert Trevellyan]

As far as I can tell, you have at least 9 ST3000DM001. Expect them all to fail early and with little warning. The upside is, your vdev layout decisions no longer have to factor in 'what to do with all my existing 3TB drives'.

This "which drive to buy" game is not an easy one

You can narrow it down a lot by limiting yourself to NAS drives. The reason to do this is to benefit from TLER. A failing desktop drive can make your whole system unresponsive, which makes addressing the problem much harder.

 

[LIGISTX]

As far as I can tell, you have at least 9 ST3000DM001. Expect them all to fail early and with little warning. The upside is, your vdev layout decisions no longer have to factor in 'what to do with all my existing 3TB drives'.

You can narrow it down a lot by limiting yourself to NAS drives. The reason to do this is to benefit from TLER. A failing desktop drive can make your whole system unresponsive, which makes addressing the problem much harder.

I can't find any info about TLER on the HGST. I just assumed since its "enterprise" it wouldn't have desktop class issues. But. There is a surprisingly small amount of info on this drive even though I have read so many good things about them as far as reliability

 

[Mirfster]

TLER (Time-Limited Error Recovery) is a WD term. For HGST and Samsung it is called CCTL (Command Completion Time Limit).

I *think* Seagate calls it ERC, but not sure since I avoid them personally.... Not knocking them just a personal preference.

 

[Mirfster]

Meh, should have known @jgreco already covered this here: "Checking for TLER, ERC, etc. support on a drive"

 

[LIGISTX]

Meh, should have known @jgreco already covered this here: "Checking for TLER, ERC, etc. support on a drive"

I swear I have googled the crap out of it, and I know I came across this before. But until I had the correct "CCTL" I was just hitting a brick wall.

Thanks!

 

[LIGISTX]

Meh, should have known @jgreco already covered this here: "Checking for TLER, ERC, etc. support on a drive"

This is from HGST's product page:

When the device is in standby mode, Streaming Commands can’t be completed while waiting for the spindle to reach operating speed even if execution time exceeds specified CCTL(Command Completion Time Limit). The minimum CCTL is 50ms.CCTL is set to 50ms when the specified value is shorter than 50ms.

There is more mention of it in the documentation, but this is much to technical for me to understand :/

https://www.hgst.com/sites/default/files/resources/MSDC4000.B_OEM_Spec_r1.0.pdf

 

[Mirfster]

Are you planning on putting the drives into Standby Mode? FWIW all of mine have always been set to "Always On".

 

[LIGISTX]

Are you planning on putting the drives into Standby Mode? FWIW all of mine have always been set to "Always On".

I don't think so. From what I have learned leaving them always spinning is better for them anyways.

But, does this mean CCTL should be fine in normal "Always on"? It seems to be saying it does support CCTL, I think?

Either way, is CCTL a make or break feature? If I am misunderstanding and it actually DOESN'T support CCTL, would it be the end of the world? To me it just seems like without CCTL it may just hang sometimes, won't actually cause a fatal data error or anything.

 

[Stux]

Can't speak to the other drives, but I learnt a lesson using green drives in the past which would drop out of raid due to non TLER.

So, as has been said, easy solution is to buy NAS drives ;)

 

[joeschmuck]

I would do my best to stick with a real NAS drive but honestly, others have reported good results using non-NAS drives. For me, saving $30 per drive was not worth the gamble. What do you get besides the small savings, normally a shorter warranty which means you are on the hook if the drive fails early.

Also, don't take one site review of 1% failure rate as gospel. If this were the magic drive then we all would have already heard of it and be pushing it on everyone. Check out many other sites for good reviews.

 

[LIGISTX]

I would do my best to stick with a real NAS drive but honestly, others have reported good results using non-NAS drives. For me, saving $30 per drive was not worth the gamble. What do you get besides the small savings, normally a shorter warranty which means you are on the hook if the drive fails early.

Also, don't take one site review of 1% failure rate as gospel. If this were the magic drive then we all would have already heard of it and be pushing it on everyone. Check out many other sites for good reviews.

Yea. That is true. I will try and find more reviews on them.

But it does look like they fully support CCTL. I found this:


"Streaming Commands
When the device is in standby mode, Streaming Commands can’t be completed while waiting for the spindle to reach operating speed even if execution time exceeds specified CCTL(Command Completion Time Limit). The minimum CCTL is 50ms.CCTL is set to 50ms when the specified value is shorter than 50ms.

Error Recover Control (SCT Command set)
When the device is in standby mode, any command where error recovery time limit is specified can’t be completed while waiting for the spindle to reach operating speed even if execution time exceeds specified recovery time limit. The minimum time limit is 6.5 second. When the specified time limit is shorter than 6.5 second, the issued command is aborted."

Still not fully sure what that means tho.


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[Robert Trevellyan]

The minimum CCTL is 50ms.

It would be silly to set it so short, so this should be a non-issue.

The minimum time limit is 6.5 second.

And I don't know what the minimum is for TLER (WD), but on my Reds it defaults to 7 seconds.

is CCTL a make or break feature?

No, but a desktop drive will try for much longer to return data when it has a problem, and this can lead to the whole box becoming unresponsive. Imagine trying to figure out which drive to replace, and to actually hit the buttons for replacement in the GUI, when every click takes several minutes to respond, or ends up timing out. We've seen this happen to people in these forums.

 

[LIGISTX]

And I don't know what the minimum is for TLER (WD), but on my Reds it defaults to 7 seconds.

So the main concern is the max limit? Low limit being 6.5 is cool and all, but I guess if the max limit is on the order of minutes (which I don't know, can't find any data on it) that is what would cause a system hang, correct?



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[Robert Trevellyan]

I guess if the max limit is on the order of minutes ... that is what would cause a system hang, correct?

You may be overthinking this. If the limit can be set to minutes and you set it to minutes, you'd end up with the same potential for an unresponsive system, but I can't imagine a NAS drive coming from the factory that way. My assumption is that the out-of-the-box value is suitable for the way the drives are intended to be used.