Added new drives to array, worried I may have missed a step.

[Guest]

It's been about a week since I added these drives but, from reading other threads about preclearing and the expected length for clearing drives, I feel I may have missed something as it didn't take nearly as long. I don't want to jeopardize my array or data so would someone please double check my work or tell me how I can confirm that these drives are properly configured/ready?

 

1. These drives were previously used in a Windows OS and formatted with NTFS. They had anywhere from 700-1200GB of data stored on each. I made sure to back up all of that data.

2. Stopped the array and unmounted each drive from the Unassigned Devices plugin interface. Added each of the drives to the array.

3. It prompted me to preclear the drives but it took less than 24 hours for 3x3TB to be cleared. Then I had to format (which finished up sometime the next day) and the array was online and working.

4. I've since performed a successful parity check.

 

Is there anything I should have done differently? Is there anything I can do or need to do to ensure that my drives are without errors/fault and my array is working properly?

[kizer]

You could of precleared which you know, but at the same time it wouldn't keep your array from coming up. Some like to run at least 3 cycles of preclearing to really work the drive over looking for possible problems that may/may not creep up over time.

 

Other that what you already know you can periodically check the smart reports looking now and then and keep a spare drive on stand by pre-cleared so you can swap it out if there is an issue.

[itimpi]

No - that sounds correct.

 

Note that you were NOT pre-clearing - you were simply clearing and this:

• Takes the array offline while the clearing is happening.  The clearing process writes zeroes to each sector
  
• Does no check on whether the clear process was successful.  It assumes that if the drive did not return a write error then the write was successful.  This is not necessarily true if the drive has some dodgy sectors.  You only find out when you do a parity check and it returns errors.
  

If you instead use the pre-clear plugin then

• The array is not offline while the clearing takes place
  
• Adding the pre-cleared disks to the array just takes seconds, and then the array is available for use again
  
• The pre-clear process checks that the writing of zeroes completed without errors
  
• The pre-clear process adds random head movements to the process to better simulate real-world scenarios in case you have any mechanical issues with the drives that can cause errors due to head alignments not being perfect.
  

[Guest]

Ah thank you both for the responses. That alleviates my fears and I will be sure to monitor the SMART reports for any errors. Also thanks for the explanation of preclear versus the normal clear and add process.

[kizer]

Leave it to itimpi to be precise and clear.

 

I wanted to say. Pre-clear beats the heck out of your drive and if it survives it passes, but didn't think it sounded to politically correct. lol