Writing to rebuilding array data disk?

[hawihoney]

How does this work?

 

There's currently a data disk rebuild running. Let's call it disk1. Now I do write to disk1. What happens?

 

There's a high potential that's there not even a valid filesystem on that disk at the time of writing.

 

My understanding is, that this new data becomes written to all other data disks and the parity disks instead. Ok, for now. But what happens after the disk rebuild is finished. The data is not on that disk.

 

Is there something like a transaction buffer that becomes applied afterwards?

 

I'm possibly totally blind, but this puzzles me since some time.

 

Edited May 14, 2021 by hawihoney

[JorgeB]

54 minutes ago, hawihoney said:

Now I do write to disk1. What happens?

The same it would if the disk wasn't rebuilding, except that it will be slower.

 

 

[hawihoney]

So, if writing to a data disk, that's currently being reconstructed, Unraid will calculate the bits with the help of all other data disks and the parity disks, writes to all parity disks and writes to the reconstructed data disk?

 

Sounds reasonable.

 

Thanks.

 

[JorgeB]

Yes, it will keep everything in sync.