'Parity is invalid' message, 2 hours, almost empty data drive

[YaSo]

I am setting up a new home Unraid server. I ran preclear on my new 16tb parity drive and a year-old 14tb data drive. I formatted the new NVME SSD as XFS that I am using for cache.

 

I started the array and saw the orange triangle for 'Parity is Invalid. After reading forum posts saying that it will go 'green' after it is done after the check is finished, I let it run. Going back to it after 2 hours, I see that the parity drive still 'orange triangle - invalid' and is reading a lot of data from the 14tb drive that has only 97mb of data on it after preclear.

 

Both drives should be 'empty'. I was going to copy data over from other drives once I set up my shares to my Windows 10 pro PC where my USB NTFS data drives are plugged in. After each drive was copied to the server, I plan to shuck it and add it as an additional empty drive to the server and add more data until 5 data drives are added.

 

Is 2+ hours to run parity on an 'empty' (almost empty) data drive normal? How long should the parity check take?

 

Thanks in advance

 

EDIT: I see that the data drive has 97 GIGS of data on it. I thought it would have been wiped when I ran preclear, it may be data left over from when I copied stuff off it it to my other USB drives in order to use shuck it and use it as my first Unraid data drive. I looked but did not see any way to format that drive before setting up the array, only to format the NVME SSD. The 16tb and the NVME drives were brand new and should not have any data on them.

Edited April 7 by YaSo
more info 97gb vs 97mb data

[itimpi]

Parity sync time is not determined by how much data you think is there but by the size of the parity drive as it works at the raw sector level and works through every sector on the parity drive.    My experience I’d something like 1-2 hours per TB of the largest parity drive size s not atypical.   You might want to read this section of the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page to get a better idea of how parity works.   The Unraid OS->Manual section in particular covers most features of the current Unraid release.

 

While a parity sync/check is active performance of the array is significantly reduced and since parity checks/syncs take so long with large modern drives you might want to consider using the Parity Check Tuning plugin to offload the check to running in increments outside prime time.

[YaSo]

23 minutes ago, itimpi said:

... My experience I’d something like 1-2 hours per TB of the largest parity drive size s not atypical. ...

 

...since parity checks/syncs take so long with large modern drives you might want to consider using the Parity Check Tuning plugin to offload the check to running in increments outside prime time.

Is it alright to stop the array in mid 'parity work' and then use the Tuning plugin you mentioned? And do you know if it will do this parity check each time I add a drive?

Also, is it alright to copy data to the data drive while the parity check is running?

(It sounds like I can copy data while it's running, but I am posting then reading the link cuz I'm paranoid and scared of damaging the drives)
thanks

 

EDIT: I just read through the parity section in the link, I already understood how parity works in general, just not that it was going to run parity for so long even if the data drive was near empty, how long it would end up taking, or if I can stop it and use a plugin and then start the array again to use the tuning plugin.

Thanks again in advance

Edited April 7 by YaSo

[itimpi]

3 hours ago, YaSo said:

Is it alright to stop the array in mid 'parity work' and then use the Tuning plugin you mentioned? And do you know if it will do this parity check each time I add a drive?

You can install the plugin with the check already running.   Not much point in stopping the current check as you would just need to start again from the beginning.   The plugin is not responsible for initiating the operation (which is Unraid’s responsibility), it just adds better management of what happens after it is started.

 

3 hours ago, YaSo said:

Also, is it alright to copy data to the data drive while the parity check is running?

Yes, but it will run much slower than when the check is not running (and also slow down the Check while they are both running) due to contention on the drives.  You should therefore avoid doing large amounts of writes to the data drives while a check/sync is running as doing them separately would end up being faster, but small amounts would be fine.

 

3 hours ago, YaSo said:

And do you know if it will do this parity check each time I add a drive?

When you add a drive, parity is not regenerated.   Instead the drive is Cleared (if not pre-cleared) to avoid it affecting parity.   You can find a discussion of Clear v Preclear here in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page. 
 

 

 

 

 

[YaSo]

Thanks @itimpi for the clarification. When I get home from work I'll install the plugin and work from there, or maybe it'll be done 'parity-ing' by then, heh heh.