Currently I have 1 parity (1T), 3 Data (1T), and 1 Cache (500G) drive.

I have ordered 3 2T drives and I want to move the parity dive to a 2T drive, move the old 1T parity drive as the cache and remove the cache drive.  After searching all I have done is confused myself.  What steps should I follow to add the drives.  Also should I preclear all the drives before I start.  The drives aren't arriving to Monday but I want to get all the info I can before I screw up my server 

You should preclear all the drives.     It gives you a chance to check for DOA drives.  If you don't do it then unRAID will and the array will be offline for the duration.  Preclearing my 2TB drives took 31 hours.  I didn't preclear all at once because mine came in different shipments.  I precleared one of them while unRAID was rebuilding one of the drives. 

 

I just upgraded some of my 1.5TB to 2TB including my parity drive.  

 

Shutdown machine.

Pull out the parity drive and insert it's replacement in the same place.

Boot up and unRAID will notice you have changed the drive.  It will have to rebuild the parity drive.  Mine took overnight to do it.

Then do the same thing with the others that you are replacing one at a time.

 

You can add any new drives just by preclearing, shutdown and add the new drives to the server.  Boot up.  Stop the array.  Go to the details tab and add the new drives.  Go back to the main tab and start the array.  unRAID will notice the new drives and you will have to tell it to format them.  The formatting will take 15 minutes or so and then they are available as part of the array.

 

 

Just as an FYI, you can replace a drive in the array without actually removing it from the machine.  Say for instance you want to replace disk3 and have precleared a new drive and both are in the machine.  You can stop the array, go to the details tab and simply drop down the disk3 listbox and select the new drive.  Then go to the Main tab and start up the array.  unRAID will rebuild disk3 on the new drive.

I want to just add a 1.5TB drive. I am already using a 1.5 for parity.

 

The Wiki talks about replacing drives with larger drives, but not just 'adding' a drive. I am assuming that all I need to do is down the system; add my drive; bring the system up; format the new drive. I am presuming that pre-clear is cleaning/erasing an existing drive, and does not apply to what I want to do.

 

 

Any thoughts or comments?

 

I want to just add a 1.5TB drive. I am already using a 1.5 for parity.

 

The Wiki talks about replacing drives with larger drives, but not just 'adding' a drive. I am assuming that all I need to do is down the system; add my drive; bring the system up; format the new drive. I am presuming that pre-clear is cleaning/erasing an existing drive, and does not apply to what I want to do.

 

Any thoughts or comments?

 

 

You should preclear the disk before adding it to your array.  Otherwise unRAID will zero it as it is added.  Any while unRAID zeros it, the array will be unavailable.

This is a brand new drive, not even formatted yet, let alone anything to clear. But I can do that.

 

However, I'm not sure what that really is or how it is done. My thoughts based on what I have found on Pre-Clear in the Wiki is that it is erasing a disk that has data before getting rid of it. (Maybe I need to search the wiki further).

 

So Is 'Preclear' an Unraid command? I do not see anything on the menus about such a command.

 

 

pre-clear is a script written by JoeL. Link to it should be in the wiki or here http://lime-technology.com/forum/index.php?topic=2817.0

 

Just because it is a new drive, does not guarentee that all the bits are Zeros.

 

In addition, the pre-clear script gives the drive a workout to check for problems with the drive BEFORE adding it to the array.

 

Although you could let unRaid clear the drive (array is unuseable during the time), it does not give the drive a workout.

 

Personally, I would never add a drive to my array without using the pre-clear script on it for at least 1 cycle. If it showed any errors, I would run multiple cycles.

 

It is to put the drive under stress. If it is going to fail you want it to fail prior to placing it into the array, not after you have your data on it.

I've purposely precleared a bad disk just to test out the script. Sure enough it came back with tons of error messages and yet I still tried to use it and within 30minutes my array had a failure followed up with an email from tower saying something was wrong.

 

For me it was a HUGE deciding factor if I should trust the system as it was explained to me. Done, Done, Done. 5TB later and I'm still doing my thing.

I was preclearing 5 drives for a customer and one came back as failed.  This was a BRAND NEW drive from Seagate that has not had any time put on it.

 

Needless to say it saved my client and I both a lot of trouble.  It saved the client from learning about the drive later on, and it saved me the headaches/complaints about shipping faulty hardware.

 

I preclear all drives, even ones not bound for unRAID use!

Thanks all. I"m sold 

 

Thanks also for the link. A search from different page than I had done before did yield results too.

 

 

The preclear script should be called the burn-in and prepare script. It burns the drive in and prepares it for use in unRAID. It gives the drive a good workout by I believe reading every sector, writing every sector then reading every sector again. I think there might be some random reading or writing in there too. That ~30hrs of the script running is continuous reading and writing on the drive.

 

It does much more than what the stock unraid will do with a new drive.

 

Peter

 

 

Might be helpful to a future reader trying to figure out when they should run preclear:

 

http://lime-technology.com/forum/index.php?topic=9399.msg89695#msg89695

I finally have all I need to install my drive, and was about to run the preclear script.

 

The problme I have, not being very linux literate, is that the instructions say this:

 

To invoke this script you simply list the name of a disk you wish cleared as an argument to the command, as in this example:

cd /boot

preclear_disk.sh /dev/hdk

 

My problem is, I don't know how to know what the name of the drive is.

 

Any suggestions?

 

[EDIT]

Never mind. I found it here->  http://lime-technology.com/forum/index.php?topic=4043.msg35774#msg35774.

 

How can you pre-clear multiple drives at a time? Open up multiple terminal windows?

 

 

How can you pre-clear multiple drives at a time? Open up multiple terminal windows?

 

 

 

Yes, this is the simplest way. You'll need to keep them all open for the duration of the script. Alternatively, you can install the screen package using unMenu. Screen will let you disconnect the terminal sessions and the reconnect later.

How can you pre-clear multiple drives at a time? Open up multiple terminal windows?

 

 

Or, use multiple virtual-consoles on the system console.  (Alt-F1 through Alt-F6 switch between them)

I did the preclear. Didn't take as long as I thought it might. Was finished after overnight run.

 

Now, I have assigned it about 3 hours ago, and on the Main screen in the browser, the START button remains greyed out. Do I need to just wait until that becomes available to start the drives up? I'm presuming it is doing the clear that is handled by Unraid, and I have another wait session at hand.

 

[EDIT]

Never mind. I see now that I just needed to click the "I am sure" box on the main screen.

Unless you were preclearing a small disk, it would not finish overnight. 2t drives can take 25-30 hours, or longer. I would be nervous if your preclear finished too quickly that it got some error and didn't finish.