Checking if drive has been cleared

[whoop]

Hi Guys,

 

Just managed to get my unraid box up and running. I have installed 2 blank drives in my PC and did went through the menu to format it. I am bit worried that the drive hasnt been cleared because the whole process took 3 hours for a 2TB seagate LP drive. Is this correct and how can I check the drive clearing was success full?

[spinbot]

I just completed running the preclear application on two 1.5TB drives and they took 18 hours each, thus I would say that you haven't precleared the drive as I you can expect it to take around 24 hours for a 2TB drive.    The technical guys will sound in when they have a chance. 

[whoop]

Just running the preclear scripts and its been clear at 106 MBps which is pretty fast. Will see if there is any failures in teh morning

[Joe L.]

Hi Guys,

 

Just managed to get my unraid box up and running. I have installed 2 blank drives in my PC and did went through the menu to format it. I am bit worried that the drive hasnt been cleared because the whole process took 3 hours for a 2TB seagate LP drive. Is this correct and how can I check the drive clearing was success full?

Clearing a disk in your PC will NOT make it bypass the clearing step in an unRAID server.  It will be cleared by the unRAID OS if it has not been pre-cleared by a program that writes a special signature to the disk.

 

There is a program I wrote that will perform that task.  It is preclear_disk.sh

You can use it to test any disk to see if a disk has the correct "preclear-signature"

 

you would invoke it as

preclear_disk -t /dev/sdX

where sdX = the device name being tested.  If you've already assigned the drives to your array then you cannot use the clearing script. (It will refuse to work on a drive assigned to the array)

 

You do not need to worry about unRAID's own clearing and formatting.  although I'd be very suspicious of 3 hours for a 2TB drive... That would be a write speed of 2000G in 180 minutes or 33.3Gig per minute, or 555MB/s.  (and NO disk I am aware of works that fast)

 

Typically the preclear_disk.sh script takes about 36 hours for a 2TB drive but then it fully reads the disk then writes the entire disk and then reads it once more.

 

Joe L.