Anyone added a 5TB disk? Curious about the pre clear time to complete

[aneelley]

I have added a 5TB to my array and it has been going for 3 days and is 51% complete.  I am pretty sure it is normal but just curious what other people's completion time was.

[SSD]

SEE HERE

 

Are you preclearing in the USB case or have you extracted the disk?

[trurl]

I have added a 5TB to my array and it has been going for 3 days and is 51% complete.  I am pretty sure it is normal but just curious what other people's completion time was.

Just to clarify, you say you have added it to the array, but your subject line is about preclearing.

 

Did you actually add the drive to the array, and now unRAID is clearing it?

Or are you preclearing the drive with the preclear script before adding it to your array?

 

[c3]

Preclear, 3 sleeps, less than 3 days, did not pay that much attention since it was ready when I expected.

Adding to array as parity, 1 sleep, about 8 hours.

adding to array as data, 1 eat, less than 1 hour.

 

PS: my kids are small so time is measured, differently...

[interwebtech]

from my post in April:

 

Preclear Successful

... Total time 40:05:21

... Pre-Read time 9:09:02 (151 MB/s)

... Zeroing time 8:11:57 (169 MB/s)

... Post-Read time 22:43:19 (61 MB/s)

 

 

Now installed in Tower1 as new parity drive

Parity-Sync in progress.   

Total size:    5 TB   

Current position:    42.5 MB (0 %)   

Estimated speed:    42.5 MB/sec   

Estimated finish:    1 day, 8 hours, 37 minutes

[superloopy]

from my post in April:

 

Preclear Successful

... Total time 40:05:21

... Pre-Read time 9:09:02 (151 MB/s)

... Zeroing time 8:11:57 (169 MB/s)

... Post-Read time 22:43:19 (61 MB/s)

 

 

Now installed in Tower1 as new parity drive

Parity-Sync in progress.   

Total size:    5 TB   

Current position:    42.5 MB (0 %)   

Estimated speed:    42.5 MB/sec   

Estimated finish:    1 day, 8 hours, 37 minutes

 

Just the one preclear  ... on a  5TB 'new to the array' parity drive, you're a brave man, gulp!

[Pro-289]

That's a-lot-a eggs.. 

[SSD]

One preclear cycle is plenty. Think about how much use that is of the drive, especially writes. How many times in its life would you typically completely write to the entire disk? Doing a bunch of cycles is like driving a car 100,000 miles before you use it to drive to work!

[superloopy]

Similar to doing a run 'around the block' in a secondhand car before purchase and finding it blows a gasket once warmed up?  Personally i'd give it a longer 'road test',three cycles to stress test it over a longer time. It is debatedly your most important drive after all. Just my opinion ... personal choice.

 

Sent from my GT-N7100 using Tapatalk

 

[SSD]

Similar to doing a run 'around the block' in a secondhand car before purchase and finding it blows a gasket once warmed up?  Personally i'd give it a longer 'road test',three cycles to stress test it over a longer time. It is debatedly your most important drive after all. Just my opinion ... personal choice.

 

Sent from my GT-N7100 using Tapatalk

 

Except instead of a trip "around the block", you are doing a trip "around the country" or maybe "a trip around the world", before putting it into service. Remember the burn in is not free - it is putting wear and tear on the drive.

 

There is certainly debate on this topic, but the most informed voices I read advocate using RAID and keeping backups, and skipping an elaborate burn in period.

 

Although it gets the most writes, the parity drive is the least important drive in an array IMO. If you lost 2 data drives you wold lose 2 disks worth of data. If you lost 1 data drive and the parity drive, you would lose only 1 drive worth of data. EVERY drive in the array is equally important if you have to do a drive recovery - parity is not special in this regard. And if you lost only the parity drive, no data reconstruction would be required. This is why I believe parity is the least important.

[superloopy]

Points taken. Like i said ... personal opinion. Each to their own. Three cycles gives 'me' peace of mind, rightly or wrongly. I'm sure there's a plethora of reasons for and against that arent worthy of further debate ....

 

Sent from my GT-N7100 using Tapatalk

 

 

[c3]

There was a survey done here about finding drive problems with X cycles of preclear. I don't think anyone found first problems after the first cycle on a new drive, in cycle two or cycle three. Yes, further problems found, but not first problems.

 

Basically, If you get a "new" drive that is not 0/0/0, get your money back.

A new drive with 0/0/0, run preclear once, if it is no longer 0/0/0 do whatever it takes to get your money back.

I have not found a new drive which completed a first preclear with 0/0/0 changing on cycle 2 or 3.

 

The "special" case is the replacement drive which arrives from warranty replacement. It arrives X/0/0, a bit scarey and you really want a reason to reject it. Repeated preclears can force it into failure.

[superloopy]

There was a survey done here about finding drive problems with X cycles of preclear. I don't think anyone found first problems after the first cycle on a new drive, in cycle two or cycle three. Yes, further problems found, but not first problems.

 

Basically, If you get a "new" drive that is not 0/0/0, get your money back.

A new drive with 0/0/0, run preclear once, if it is no longer 0/0/0 do whatever it takes to get your money back.

I have not found a new drive which completed a first preclear with 0/0/0 changing on cycle 2 or 3.

 

The "special" case is the replacement drive which arrives from warranty replacement. It arrives X/0/0, a bit scarey and you really want a reason to reject it. Repeated preclears can force it into failure.

 

I dont understand your reasoning here. Are you saying that if a drive doesn't fail after, let's say 3 preclears as opposed to the 1 being advocated, that it's inherently more resilient by virtue of the fact that 'repeated preclears can force it into failure'? If so ... i agree.

 

Sent from my GT-N7100 using Tapatalk

 

 

[c3]

Although it gets the most writes, the parity drive is the least important drive in an array IMO. If you lost 2 data drives you wold lose 2 disks worth of data. If you lost 1 data drive and the parity drive, you would lose only 1 drive worth of data. EVERY drive in the array is equally important if you have to do a drive recovery - parity is not special in this regard. And if you lost only the parity drive, no data reconstruction would be required. This is why I believe parity is the least important.

 

Good point, also parity drive are typically replaced/shuffled sooner, since it needs to be the newer larger size.

[BRiT]

There was a survey done here about finding drive problems with X cycles of preclear. I don't think anyone found first problems after the first cycle on a new drive, in cycle two or cycle three. Yes, further problems found, but not first problems.

 

Basically, If you get a "new" drive that is not 0/0/0, get your money back.

A new drive with 0/0/0, run preclear once, if it is no longer 0/0/0 do whatever it takes to get your money back.

I have not found a new drive which completed a first preclear with 0/0/0 changing on cycle 2 or 3.

 

The "special" case is the replacement drive which arrives from warranty replacement. It arrives X/0/0, a bit scarey and you really want a reason to reject it. Repeated preclears can force it into failure.

 

I dont understand your reasoning here. Are you saying that if a drive doesn't fail after, let's say 3 preclears as opposed to the 1 being advocated, that it's inherently more resilient by virtue of the fact that 'repeated preclears can force it into failure'? If so ... i agree.

 

Sent from my GT-N7100 using Tapatalk

 

Drive failures follow the bathtub curve. Either they fail extremely early in their lifetime or they don't fail until the very end.

 

I've had numerous drives easily pass the first preclear pass but then fail in extreme ways on pass 2 or 3. It was rare for me to have drives fail on the first pass. I would not do any less than 3 preclear passes.

[superloopy]

There was a survey done here about finding drive problems with X cycles of preclear. I don't think anyone found first problems after the first cycle on a new drive, in cycle two or cycle three. Yes, further problems found, but not first problems.

 

Basically, If you get a "new" drive that is not 0/0/0, get your money back.

A new drive with 0/0/0, run preclear once, if it is no longer 0/0/0 do whatever it takes to get your money back.

I have not found a new drive which completed a first preclear with 0/0/0 changing on cycle 2 or 3.

 

The "special" case is the replacement drive which arrives from warranty replacement. It arrives X/0/0, a bit scarey and you really want a reason to reject it. Repeated preclears can force it into failure.

 

I dont understand your reasoning here. Are you saying that if a drive doesn't fail after, let's say 3 preclears as opposed to the 1 being advocated, that it's inherently more resilient by virtue of the fact that 'repeated preclears can force it into failure'? If so ... i agree.

 

Sent from my GT-N7100 using Tapatalk

 

Drive failures follow the bathtub curve. Either they fail extremely early in their lifetime or they don't fail until the very end.

 

I've had numerous drives easily pass the first preclear pass but then fail in extreme ways on pass 2 or 3. It was rare for me to have drives fail on the first pass. I would not do any less than 3 preclear passes.

 

Well said that man!

 

I would be concerned if i had to replace a failed parity drive. The risk of losing a data drive due to having to 'reconstruct' such a failure is not one i hope to experience. Dont forget your data disks themselves are also under their most stress during a rebuild (does everyone preclear data disks 3 times as well?) and that if a parity drive faulted you have nothing left to rebuild from at that point. That is why MY, and i must stress its only my choice, parity disk MUST go through at least 3 stress test before i'm prepared to let it anywhere near my data.

 

Sent from my GT-N7100 using Tapatalk

 

[BobPhoenix]

I've had drives change smart attributes (some literally fail - no longer recognized on any PC) on later cycles but most do fail on the first if they fail at all.  Percentage wise for me it is roughly this 40% of the failures are totally dead on arrival either unrecognized or do not even start a preclear, 30% after first pass show bad smart, 20% after 2nd pass and 10% after the third.  I've got a 3TB WD EARS drive that flips from 65535 to zero to 65535 on pending sectors depending on the preclear cycle.  It has been through at least 6.  It was suggested to me that it has bad firmware.

[superloopy]

BobPhoenix ... the fact that you have a not inconsiderable percentage of drives that pass the first but not subsequent preclear passes is good enough for me to continue with a '3 pass' preclear policy. Seems to say it all ... you reap what you sow

 

Sent from my GT-N7100 using Tapatalk

 

[SSD]

I've had numerous drives easily pass the first preclear pass but then fail in extreme ways on pass 2 or 3. It was rare for me to have drives fail on the first pass. I would not do any less than 3 preclear passes.

 

What brand / model drives are you buying? I can't say I've had a lot of drives fail since 2008 when I started.

 

The advice on preclears is my opinion based on my experiences and research. I don't think there is any wrong answer. My point was the amount of wear and tear you are putting on the drive prior to using it is very significant.

[superloopy]

Think we agree that the drive is being 'stressed' by doing multiple preclears safe in the knowledge that if it gets through this test without any issues then it has proven its robustness. Should be good enough to put to use ...

 

Sent from my GT-N7100 using Tapatalk

 

[garycase]

I think 5TB drives will go the way of the 1.5TB drives a few years ago => very short market life due to the evolution of capacity.  6TB drives are already available for a bit more/TB => and if I was going to upgrade my system to larger drives I'd certainly use those.

 

I'm wondering if the reason WD hasn't released the long-promised 5TB WD Reds is that they're skipping that capacity level in favor of 6TB  (only time will tell, but I doubt they'll be without a > 4TB drive much longer).