Swap jumpered parity 2TB WD drive with unjumpered one?

[Ned]

I have a system running version 4.5.4 with a WD 2TB EADS drive as my parity drive.  I jumpered it before adding it into the system and all is good.

 

I am about to add another 2TB drive (WD EARS).  Since 4.7 is now out and I can install this new drive without the jumper, I am wondering if there would be any benefit to replacing the existing jumpered parity drive with the new unjumpered drive and then adding the old jumpered parity drive as a new data drive in the array?  Or should I just leave the system as is, and add the new un-jumpered drive as a new data drive in the array?  Would there be any difference in performance or reliability in either configuration?  All of these changes would take place after first upgrading the system to 4.7 of course!

 

Any comments or advice would be appreciated.

[SSD]

EADS drives are not advanced format, and do not have jumpers.  You would get good performance from an EADS drive regardless of whether is was aligned or not aligned.  Swapping it out for an aligned EARS drive should not have any impact.  If you swapped it with a 7200 RPM drive, and were writing to another 7200 RPM data drive, your performance would improve.

[Ned]

Thanks for the info... I didn't realize the EADS models were not advanced format!  Now you have prompted another question - I put a jumpter on pins 7/8 before I added the EADS drive to the array... is this going to create a problem since it is not an advanced format drive?!?  It has been running as my parity drive for a couple of months...

[SSD]

Thanks for the info... I didn't realize the EADS models were not advanced format!  Now you have prompted another question - I put a jumpter on pins 7/8 before I added the EADS drive to the array... is this going to create a problem since it is not an advanced format drive?!?  It has been running as my parity drive for a couple of months...

 

There have been some reports that some select few EADS are actually advanced format.  I have never seen one, and bought 2 near the end of the EADS lifespan that have late "born on" dates, and they are not AF.  I doubt very seriously that EADS drives are advanced format.

 

I have no idea what impact the jumper you installed would have.  You might look at the manual to see if it is documents.  Some of those jumpers would reduce the capacity of the disk (you might notice), affect whether the drive spins up automatically or not (you might notice if the drive did not spin up on boot), and whether the drive runs a 1.5Gb/sec (SATA I) or 3.0Gb/sec (SATA II) speeds.  I am not sure if the 7/8 jumper affects one of these or not.

[Ned]

I looked at the manual and for the non-AF drives all it says is that pins 7-8 are "reserved for factory use".... the drive appears to be functioning correctly.  No parity sync errors and speed-wise everything is just as fast or faster than it used to be.  Still has me worried though.

 

Once the jumper is set, can it ever be removed?  I'm guessing that taking the drive out, removing the jumper and re-installing the drive would be a bad idea?

[SSD]

I looked at the manual and for the non-AF drives all it says is that pins 7-8 are "reserved for factory use".... the drive appears to be functioning correctly.  No parity sync errors and speed-wise everything is just as fast or faster than it used to be.  Still has me worried though.

 

Once the jumper is set, can it ever be removed?  I'm guessing that taking the drive out, removing the jumper and re-installing the drive would be a bad idea?

 

You are in new and uncharted territory!  I would not be excited about running with a "factory use only" jumper, but it may have no negative impact at all.  You might consider sending an email to WD support asking advice.  You could also, if you wanted, run a full parity check (to make sure there are not problems), and then remove the drive, pull the jumper, and put it back in, and run a parity check again.  If you are getting no sync errors all is good.  If you start getting lots of them, you could reset the configuration and have it rebuild parity.  100% your call.

[Ned]

Ok thanks for the advice... I sent a note off to WD about this, and will hold off until I get a reply :-)

[Grizz1968]

Since you have a new drive ready to go in the server, I would think to do the following I may be wrong but I will give it a shot.

 

1. Run Parity Check (if all good proceed)

2. Power Down Server

3. Install new drive in the Parity Slot

4. Let Parity rebuild (if all good then proceed)

5. Remove the jumper and you can then run the preclear script and then format drive to start with a nice clean drive

[Ned]

Good idea, thanks...  parity check is clean right now.

 

Just to confirm - before I take out the EADS drive and swap in the EARS drive, I need to upgrade the server to 4.7 right?  If things are running fine right now, upgrading to 4.7 should have no impact on the current drive configurations?

 

Last thing - can you provide some instructions on how to run this preclear script?

[Grizz1968]

Yes if you haven't completed the update to 4.7 now would be a good time to complete this as well.  Before doing any upgrade I also make sure I have a screen capture of the drive locations the last tab on the main unRaid screen in case you do need to re-assign the drives (you shouldn't have to) but better to be safe than sorry.

 

Here is information on the preclear script

http://lime-technology.com/forum/index.php?topic=2817.0

[SSD]

My guess is that factory use = not currently used,  but you'll have to wait to see if WD answers the question.

[Ned]

Thanks for the advice... I normally do that as well before an upgrade :-)

 

One more question - I am nervous about running this pre-clear script on a drive in the unRAID box.  I don't want to accidentally pre-clear the wrong drive or something like that!  Instead, can I not take the drive out completely and re-align it (or do whatever to "fix" it) using that WD utility on my windows PC?  Why is it even necessary to do this?  If I just take off the jumper and add the drive as a new data drive in the array, won't the regular formatting process that unraid performs take care of everything?

 

Would be nice if indeed "factory use" = "currently not used" on the non-AF drives... then I really don't have to do anything at all... fingers crossed :-)

[Joe L.]

Thanks for the advice... I normally do that as well before an upgrade :-)

 

One more question - I am nervous about running this pre-clear script on a drive in the unRAID box.  I don't want to accidentally pre-clear the wrong drive or something like that!

The script will not let you clear a drive assigned in the array, or a drive that is mounted.  It also prompts you with the model AND serial number of the drive before asking for confirmation it will proceed.  Now, if you have two drives not assigned to the array, and not otherwise in use, then it is possible to clear the wrong un-assigned drive.   Easiest is to use

preclear_disk.sh -l

to get a list of the disks and affiliated devices.  Then you can match up the model/serial numbers of the disk.   Just make sure you download and use the most current preclear_disk.sh script.  (currently version 1.

 Instead, can I not take the drive outcompletely and re-align it (or do whatever to "fix" it) using that WD utility on my windows PC?

Probably not, since it probably does nothing to change the partitioning on the disk.

Why is it even necessary to do this?  If I just take off the jumper and add the drive as a new data drive in the array, won't the regular formatting process that unraid performs take care of everything?

You can certainly give it a try.   It will use the existing partition on the disk if it thinks it finds one.  You must remove the existing partition first if you want to change the start of the partition.

Would be nice if indeed "factory use" = "currently not used" on the non-AF drives... then I really don't have to do anything at all... fingers crossed :-)

It would be nice, but you never know.  Some manufactures use the extra pins for communicating with the disks in their initial testing and firmware initialization.

[Ned]

Thanks for the info Joe. L!

 

If all I need to do is "remove the existing partition" before adding to the array and letting unraid format the drive, can I not just use the windows disk management utility to remove any partitions, leaving the drive as one big block of unpartitioned space?

[Joe L.]

Thanks for the info Joe. L!

 

If all I need to do is "remove the existing partition" before adding to the array and letting unraid format the drive, can I not just use the windows disk management utility to remove any partitions, leaving the drive as one big block of unpartitioned space?

yes, that will work too, but if the disk is in the unRAID array, typing:

preclear_disk.sh -z /dev/sdX

(where /dev/sdX = your device to be cleared)

will clear the MBR and you don't have to move the disk physically.

 

You can type

preclear_disk.sh -l

to get the device names of the disks not assigned to your array.

 

Again, you'll be prompted to confirm you have the correct disk, and will be shown the model/serial number of the disk before it will continue.

You must answer with

Yes

(capital "Y", lower case "es) as anything else will cause it to not zero the MBR.

 

Joe L.

[lionelhutz]

Also set the default partition format to 4k aligned on the options page before swapping in the EARS drive.

 

My 1.5T EADS drive is about the slowest drive I have so I would not be surprized if you find array writes are a little quicker with the EARS drive instead.

 

Peter

 

[Ned]

Thanks everyone for your replies... I got the following answers from WD email support for those who are interested:

 

"you can safely leave the jumper placed onto pins 7 & 8 since those pins are unassigned to any particular property of your HD.

 

If you have any further questions, please reply to this email and we will be happy to assist you further.

 

Sincerely,

Hector N

Western Digital Service and Support"

 

 

I then replied and asked:

"So just one final confirmation then... you state that pins 7 & 8 on this drive are unassigned to any particular property of the drive... I understand that to mean that this jumper is not actually doing anything then? Can I safely remove it with absolutely no effect to the drive or the data on it?"

 

To which WD replied with:

 

"there is not a precise answer to your last question. On our test machine, I was able to remove the jumper and the drive was still accessible. Now then, since each PC is different as well as that we haven't yet tried this procedure on multiple HDs (+100) to verify the behavior and thus to issue a formal knowledge base article, please backup your data prior to taking out the jumper out of the HD.

 

If you have any further questions, please reply to this email and we will be happy to assist you further.

 

Sincerely,

Hector N "

 

I've since sent them one more question to try and get 100% confirmation that there will be no adverse effect on the physical functioning or performance of the drive itself by removing the jumper.  I don't care about the data as I will be formatting the drive anyway... but just want them to confirm in writing (hopefully) that the drive itself will be ok.  I will post their reply when I get it...

 

 

[Ned]

And here is WD's reply to that last question!:

 

"rest assured that no physical damage will occur by taking the jumper out of the HD".

 

So, given my situation, I think it would then make sense to do the following:

 

1) Upgrade to 4.7 and set default partition format to 4k aligned

2) remove jumpered parity EADS drive and replace with the new non-jumpered EARS drive I just bought as the new parity drive.  Rebuild parity.

3) remove the jumper on the old parity EADS drive

4) pre-clear the EADS drive (I would imagine this step is actually optional since WD said the jumpers have no assigned property on this drive, but I'll do it anyway to be safe)

5) add the now un-jumpered EADS drive to the array as a new data drive

 

Does this approach make the most sense?

[SSD]

Looks like my guess was right!

 

My guess is that factory use = not currently used,  but you'll have to wait to see if WD answers the question.

 

And here is WD's reply to that last question!:

 

"rest assured that no physical damage will occur by taking the jumper out of the HD".

 

So, given my situation, I think it would then make sense to do the following:

 

1) Upgrade to 4.7 and set default partition format to 4k aligned

2) remove jumpered parity EADS drive and replace with the new non-jumpered EARS drive I just bought as the new parity drive.  Rebuild parity.

3) remove the jumper on the old parity EADS drive

4) pre-clear the EADS drive (I would imagine this step is actually optional since WD said the jumpers have no assigned property on this drive, but I'll do it anyway to be safe)

5) add the now un-jumpered EADS drive to the array as a new data drive

 

Does this approach make the most sense?

 

I would not do this.  I don't understand why you want to change the EADS parity.  No reason to do that.

 

The trick with unRAID is to NOT rebuild parity unless absolutely necessasry.  Because every time you do, you expose yourself to losing data on a SINGLE drive failure.

 

What I would do is the following ...

 

1.  Power down, remove the EADS, remove the jumper, put the EADS back into the server, power up.  Since WD said those pins are not used, it really is not necessary to do this, but you may feel better (I know I would) not having that jumper in place.

 

2.  Run a parity check and let it run for 5-10 minutes.  If sync errors are zero, stop it.  The drive is fine.  Leave it as the parity disk.

 

3.  Upgrade to 4.7 and set default partition format to 4k aligned

 

4.  Preclear the new EARS drive and add it as a data disk following normal procedures.

 

5.  Run a full parity check to be 100% confident that everything is protected.

 

This completely eliminates any need to lose parity.

 

That's what I would do.

[Ned]

Thank you for the advice, I appreciate it!  I think your approach makes perfect sense.

[lionelhutz]

You can recover if you keep the old parity drive and do not write to the array during the parity build.

 

If you are looking to have a faster write speed then try the EARS as parity. Otherwise don't bother touching the EADS and just use the EARS as a data drive.

 

Peter

 

[Ned]

Just thought I'd let everyone know that after removing the jumper from the EADS drive, everything was still fine.  Parity still checked out and no sync errors.

 

Thanks everyone for your help and advice.