Which 2 TB drive should I buy?


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Thanks Aiden, This is excellent advice for me, since I'm about to start building.  I was still confused on "safe" protocol to do preclears with my mix of drives.

Well, don't take it as Gospel - it's just the procedure I follow.  ;D  At one time, before these monster 2TB drives were maintstream, Joe had recommended up to 10 preclear cycles on a new drive!  

 

My logic is based on the idea that a new drive has no SMART data for preclear cycles to compare against, so 3 cycles give a decent minimal number of SMART datasets for a baseline comparison.  In a used drive, SMART has been active and should already have a starting set of values, so I reduce the cycle count by one.  I'm sure Joe can shoot this full of holes, starting with the disclaimer that preclearing doesn't provide a 100% guarantee of disk health, it's just a much better thermometer.

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Thanks Aiden, This is excellent advice for me, since I'm about to start building.  I was still confused on "safe" protocol to do preclears with my mix of drives.

Well, don't take it as gospel - it's just the procedure I follow.  ;D  At one time, before these monster 2TB drives were maintstream, Joe had recommended up to 10 preclear cycles!  My logic is based on the idea that a new drive has no SMART data for preclear cycles to compare against, so 3 cycles give a decent minimal number of SMART datasets for a baseline comparison.  In a used drive, SMART has been active and should already have a starting set of values, so I reduce the cycle count by one.  I'm sure Joe can shoot this full of holes, starting with the disclaimer that preclearing doesn't provide a 100% guarantee of disk health, it's just a much better thermometer.

 

No worries, I've been around enough not to take anything as Gospel...But if it works for you, I have something to try for my own run-up. Something that has been tested. I believe Joe will be OK with us understanding that there are no 100% guarantees when it comes to risk of hardware failure. All hard drives do one thing-they eventually fail...all of them, so no worries, we're on the same page.

Thanks,

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I ran an HD Tune error scan on my 5K3000 drive overnight and it came back 0 bad sectors, but looking at the SMART info there are 4 unsafe shut downs and 4 power cycles. Even my F4 that has been in service for 6+ months has zero unsafe shut downs. Any idea what this means?

 

HD Tune may have done something the drive controller firmware did not like

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My rig is finally a reality!   ;D

 

Since I could not find the PSU I wanted, went a bit smaller of same brand, and built it. The wait was.....  ::)

 

Took very few photos of actual build, but will post what I have soon.

 

This is it-

UNRAID Pro License

unMenu and Preclear are in. Mail and most others still to install n configure.

Bits in already:

Fractal XL Black case with one extra Fractal 140mm Fan. -Still playing w the Airflow. Cooling is rather quiet but here in Sydney still far from ideal.

ASUS M4A78LT-M LE MB

AMD Athlon II 260 CPU

Kingston 4GB (2x2) DDR3 RAM

Supermicro Card and Breakaway cables

PSU Seasonic 620Watt S12II Bronze

 

Drives-

1 Hitachi 7K2000 2TB for parity

2TB X3 Data drives (2 7K2000 Hitachi, one Seagate LD Green)

One Seagate 500GB for cache.

 

One Hitachi Green is next ADD. Waiting for Post.

 

Now running Preclear. currently at 11 Hours for all 2TB drives. Cache (smaller) drive finished quickly, w 0 errors.

It's virtually silent w Drive temps between 48 and 32 Degrees. Now re-reading the tutorials, etc.

Still need to do Mail, shares etc.

 

Tower can be seen and managed by my wired network PCs and Wireless Mac, but not even seen on network by my laptop via wireless. Although not unRAID related, any help, ideas with this will be appreciated.

All PC on Windows 7, Mac on latest OS.

 

Cheers,

Ramon

 

 

 

 

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First Preclear reports.

 

How shall I say this? We live and learn. First drive to  be on Step 10 of 10 of Preclear was my new 2TB Seagate LD Green drive. Also running the lowest temp of the 2Tb drives, at 39 Degrees. All other 2 tera drives still at it,  between 90 and 96% complete or starting step 10 of 10-the verifying the MBR step.

 

I believe I have a new FAV drive on my expansion shopping list w these Seagates LD.   :)

Thanks to Smurf for the tip on these Seagates.

 

 

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Hi

Thanks for confirming that aiden. Was wondering since that has been my experience in these last 15 hours with these 2TB drives. The Seagate is running first, and at a lower temp, and the 3 Hitachis are not following any discernible pattern.  One of them is still  doing step 2 of 2, and the other two  are at Step 10. All 3 Hitachis (the only 7200 RPM units I'm running) at 40 to 42 Degrees now. They were closer to 48-49 a few hours ago.

 

All steps seem to be running well. Will I see a summary report per drive? How can I save these preclear reports, do you know?

 

Thanks,

Ramon

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I am getting a little worried about my "batch order" :-[

 

I hope I don't live to regret it - looks like got a lot of preclear ahead of me >:(

Will post results...

 

Finished the first preclear cycle of 3 on the 8 Hitachi drives and no errors on any of them. So thankfully (so far..) it is not a bad batch. Now running 2nd.

Took about 24:30 hrs to do the cycle and the drives did all finish at different times even though they started roughly the same time.

Temps got a bit high, even saw 51c at one point for about an hour. It might be that my quiet 120mm fans are just not moving enough air.

The interesting thing (kept looking at  console for errors!) I noticed is how much the read/write speeds drop toward the end of the cycle - from about 112MBs at the start to about 70MBs toward the end. I assume the heads have to travel further as they work the outer edges of the platter? Or is that not the reason?

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The preclear will generate a temporary log file that you can save if you wish.  Joe can probably give you the exact file location because I can't remember offhand.

 

Thanks Aiden. I hope that log file remains there by default.  Was about to ask joe on saving a copy , and found his instructions on the config tutorial. Will try these first. If no go, will ask.  

Excellent!

By the Way, the 500GB (my cache drive) finished w no errors. Others are at Post read still.

Would post here a screen print image of Telnet (Putty) screen showing Parity drive at post read, if I knew how. Have saved image for now.

 

I am getting a little worried about my "batch order" :-[

 

I hope I don't live to regret it - looks like got a lot of preclear ahead of me >:(

Will post results...

 

Finished the first preclear cycle of 3 on the 8 Hitachi drives and no errors on any of them. So thankfully (so far..) it is not a bad batch. Now running 2nd.

Took about 24:30 hrs to do the cycle and the drives did all finish at different times even though they started roughly the same time.

Temps got a bit high, even saw 51c at one point for about an hour. It might be that my quiet 120mm fans are just not moving enough air.

The interesting thing (kept looking at  console for errors!) I noticed is how much the read/write speeds drop toward the end of the cycle - from about 112MBs at the start to about 70MBs toward the end. I assume the heads have to travel further as they work the outer edges of the platter? Or is that not the reason?

 

Keyvan, Good to hear you got what seems to be a good batch of Hitachis.

I was so concerned w the bad batch possibilities, that went and bought the Seagate Green locally, instead of repeating my order for another Hitachi Green from same supplier in USA where I got my Green still somewhere over the Pacific.

From the preclear results I'm seeing, not a bad choice the Seagate Green LD. At this stage I'm inclined to Eventually expand my rig w Seagates.

About the read speeds, mine changed mostly drive to drive, but seem to be holding rather consistently. Hitachi around 105 MB/S and the Seagate at around 116 MB/S.  Mind you, I've only looked once every hour or so.

 

 

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...I noticed is how much the read/write speeds drop toward the end of the cycle - from about 112MBs at the start to about 70MBs toward the end. I assume the heads have to travel further as they work the outer edges of the platter? Or is that not the reason?

Yes, it has to do with distance from the edge of the platter.  It's really just a physics lesson.  At the edge of a platter, the rotational speed is at its highest point, meaning the edge of the disk is moving faster.  As the head moves closer to the spindle, this rotational speed is slower, because the distance required to make a complete revolution is smaller than at the edge.  Thus, all mechanical drives that record on spinning disks will be slowest at the spindle, and fastest at the edge.

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...I noticed is how much the read/write speeds drop toward the end of the cycle - from about 112MBs at the start to about 70MBs toward the end. I assume the heads have to travel further as they work the outer edges of the platter? Or is that not the reason?

Yes, it has to do with distance from the edge of the platter.  It's really just a physics lesson.  At the edge of a platter, the rotational speed is at its highest point, meaning the edge of the disk is moving faster.  As the head moves closer to the spindle, this rotational speed is slower, because the distance required to make a complete revolution is smaller than at the edge.  Thus, all mechanical drives that record on spinning disks will be slowest at the spindle, and fastest at the edge.

 

Quite logical. Another random look at the readouts confirms this. range seems to be between 98 and 111 MB/S for my Hitachis, and 101 to 121 for the Seagate. All progressing well at this stage (17:30 Hrs of preclear).

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If you are using the current version of the preclear_disk.sh script, then an automatic date-stamped set of flies per disk is automatically stored in the preclear_reports directory on your boot disk when the preclear finishes.  The same information is also logged to the syslog.  The Configuration tutorial is probably not up to date if it does not mention the /boot/preclear_reports directory.

 

The initial SMART report, the final SMART report, and the preclear report are all saved.  (only the last set of reports per drive, per day, is saved.)

 

Joe L.

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If you are using the current version of the preclear_disk.sh script, then an automatic date-stamped set of flies per disk is automatically stored in the preclear_reports directory on your boot disk when the preclear finishes.  The same information is also logged to the syslog.  The Configuration tutorial is probably not up to date if it does not mention the /boot/preclear_reports directory.

 

The initial SMART report, the final SMART report, and the preclear report are all saved.  (only the last set of reports per drive, per day, is saved.)

 

Joe L.

 

Excellent. Thanks a lot, Joe. I'm using latest available preclear download-from two days ago. 1.6, I believe.

At what level are these saved, at root? If I wanted to copy these and create txt files or something for my records (on my PC), what would be best method?

Thanks,

Ramon

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If you are using the current version of the preclear_disk.sh script, then an automatic date-stamped set of flies per disk is automatically stored in the preclear_reports directory on your boot disk when the preclear finishes.   The same information is also logged to the syslog.   The Configuration tutorial is probably not up to date if it does not mention the /boot/preclear_reports directory.

 

The initial SMART report, the final SMART report, and the preclear report are all saved.  (only the last set of reports per drive, per day, is saved.)

 

Joe L.

 

Excellent. Thanks a lot, Joe. I'm using latest available preclear download-from two days ago. 1.6, I believe.

At what level are these saved, at root? If I wanted to copy these and create txt files or something for my records (on my PC), what would be best method?

Thanks,

Ramon

They would be at \\tower\flash\preclear_reports\

 

Just copy them from there to your PC.  They are already text files.

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If you are using the current version of the preclear_disk.sh script, then an automatic date-stamped set of flies per disk is automatically stored in the preclear_reports directory on your boot disk when the preclear finishes.  The same information is also logged to the syslog.  The Configuration tutorial is probably not up to date if it does not mention the /boot/preclear_reports directory.

 

The initial SMART report, the final SMART report, and the preclear report are all saved.  (only the last set of reports per drive, per day, is saved.)

 

Joe L.

 

Excellent. Thanks a lot, Joe. I'm using latest available preclear download-from two days ago. 1.6, I believe.

At what level are these saved, at root? If I wanted to copy these and create txt files or something for my records (on my PC), what would be best method?

Thanks,

Ramon

They would be at \\tower\flash\preclear_reports\

 

Just copy them from there to your PC.  They are already text files.

 

Thank you. Will do.

Best,

ramon

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AF is not a requirement, or even a benefit, really.  It's just the "new kid" as far as sector mapping goes.  I wouldn't worry too much about that.

 

http://bcove.me/fsmy7blt

 

Just saw this video on seagates's website which pretty much confirms what you were saying about AF. It seems it has more to do with the future of high capacity drives than what it has to offer the current crop of 2Tb drives. It does explain a bit more about the technology -with a seagate plug of course..! Interesting for me as I am not an expert on the subject.

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They would be at \\tower\flash\preclear_reports\

Just copy them from there to your PC.  They are already text files

 

 

Done!

 

All 5 preclear runs finished without errors reported for my drives. Today copying preclear report file.

Average preclear runtime for 2TB drives at ~27 hours.

Array w parity created. Now to the shares. This is geek porn!!  ;D

 

Thanks again for all the help and support!

 

 

 

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Take a look here: http://lime-technology.com/forum/index.php?topic=11370.0

 

Seems that Samsung F3 HD203WI doesn't return smart temp reading without spinning up first, which WD20EARS do not need. Makes the WD20EARS a clear winner for people who want to control fan speed based on actual HDD temp.

 

Excellent. Thanks for the link.

I just noticed same issue with my only 500GB HDD (a Seagate 7200.11). I just reassigned this smaller  drive. Was for cache, and made it part of the Array. and temps reporting was an issue for a moment there.

Maybe same reason. Will check in a few days and report.

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Take a look here: http://lime-technology.com/forum/index.php?topic=11370.0

 

Seems that Samsung F3 HD203WI doesn't return smart temp reading without spinning up first, which WD20EARS do not need. Makes the WD20EARS a clear winner for people who want to control fan speed based on actual HDD temp.

 

This is not true anymore.  As long as the fan speed control script ignores drives that are sleeping, it will leave them alone.  This makes it possible to use fan speed based on hard drive temp for any drive.

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Take a look here: http://lime-technology.com/forum/index.php?topic=11370.0

 

Seems that Samsung F3 HD203WI doesn't return smart temp reading without spinning up first, which WD20EARS do not need. Makes the WD20EARS a clear winner for people who want to control fan speed based on actual HDD temp.

 

This is not true anymore.  As long as the fan speed control script ignores drives that are sleeping, it will leave them alone.  This makes it possible to use fan speed based on hard drive temp for any drive.

 

Yeah, but drive sleeping doesn't mean the drive itself is cool and doesn't need cooling.. But a nice workaround, aiden! Thanks!

 

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