Hi,

 

As most of us I'm doing pre-clear rarely. I just run docker app binhex-preclear on new 8 TB. It took 53 hours to finish. Afterwards I added the disk to array. Disk didn't show up nicely as I expected, instead it just disappear from Unassigned devices list and from the list of devices ready to be added to the array (just like the addition was successful). So I did reset before spinning up the array. Now the disk is showing up on the array devices list. That's good, I have an improvement. I started an array and instead of having disk up and running I can see, he is now doing some "Write" operations and for a short moment I saw info about pre-clearing. In the array the status is "unassigned".

 

Anyone knows what is happening? I really didn't want to wait two more days for disk to be cleared again... Also I don't understand why there is no clear status info what is happening. Bad app design. If pre-clearing has been run for the second time - is there a way to stop it since it is not really needed and mark disk so it can be included into the array?

 

I'm running Unraid 6.12.4

 

[EDIT] ok - an update - I can now see following info: "PARITY Disk-Clear in progress... Completed: 13.7 %.". So:

- seems like what is happening is "PARITY Disk-Clear in progress" and

- progress is 13.7 %

 

13.7% is too fast for pre-clearing 8 TB, so this is something different I guess. Maybe some additional operation on parity drive as written in status info.

 

Will keep you updated

 

[EDIT 2] so... all done... array++ with 8TB. Writes were going to new disk most probably due to some kind of sync with parity drive. Looks like this is a part of normal array expansion process. Maybe one sentence of explanation in binhex-preclear would be good to have.

 

BR

AltCtrlDel

 

Edited October 4, 20232 yr by AltCtrlDel

Not that I am an expert on this but as far as I know, the special flag to tell Unraid the drive is "cleared" is only set at the end of a successful preclear script execution.

 

If a new disk is not properly cleared, Unraid must clear it before use as part of the array. This would be (among other reasons) to prevent any possibility of old data on a drive becoming part of a parity calculation and wreaking havoc on your once-good data elsewhere in the array.

 

Clearing is just writing zeroes to all spots on a disk, where preclear reads, then writes, then verifies for each of its cycles, unless you change its settings to skip some of those steps. That's why you saw the large time difference.