(SOLVED) How to avoid a Parity-Check on a nearly empty array?

[icopy]

I'm new to unraid. I've just setup an array with 5 new Toshiba 4T hard drive. 4 data and 1 parity. Also I added a nvme ssd as cache. I transfered about 120+G files for testing.

Somehow after a reboot, the parity drive requires a parity-check. I don't think it's necesary and I don't want to do this parity-sync. So I've tried to:

a) change the file system for all data drives and format all data drives.

b) reset the array.

Yet the unraid os still asks to do a parity-sync.

 

How can I avoid this parity-check?  Thx.

Edited February 26, 2020 by icopy

[JorgeB]

If Unraid did a parity after a reboot it means there was an unclean shutdown and you should let it finish, and if you want to avoid it the only is doing a new config and checking "parity is already" valid before starting the array, but you risk being left with invalid parity in case of a disk failure.

[icopy]

5 minutes ago, johnnie.black said:

If Unraid did a parity after a reboot it means there was an unclean shutdown and you should let it finish, and if you want to avoid it the only is doing a new config and checking "parity is already" valid before starting the array, but you risk being left with invalid parity in case of a disk failure.

Thanks for the reply.

If I check "parity is already" as you've suggested, will I lose data in the future? Even though I don't have any data at the moment.

Is this the recommended way to start a new array?

[JorgeB]

13 minutes ago, icopy said:

Even though I don't have any data at the moment.

Parity is calculated sector by sector, no data or empty doesn't mean anything, only if all the disks were cleared (or precleared) and all zeros can you safely use parity is already valid.

[itimpi]

When setting up a new array one always needs to go through building the initial parity.  This is required despite the fact thzt there is no dzta present as parity does not understand data - only bit patterns.

 

In your case since it appears you had valid parity you may be able to use Tools >> New Config to reset the array and then tick the "Parity is already valid" box.   However this is risky and I would recommend rebuilding parity to play safe.

 

[icopy]

4 minutes ago, johnnie.black said:

Parity is calculated sector by sector, no data or empty doesn't mean anything, only if all the disks were cleared (or precleared) and all zeros can you safely use parity is already valid.

Great info, Thx.

[icopy]

3 minutes ago, itimpi said:

When setting up a new array one always needs to go through building the initial parity.  This is required despite the fact thzt there is no dzta present as parity does not understand data - only bit patterns.

 

In your case since it appears you had valid parity you may be able to use Tools >> New Config to reset the array and then tick the "Parity is already valid" box.   However this is risky and I would recommend rebuilding parity to play safe.

 

Doing the parity-check now. Thx!