replacing parity drive with larger capacity

[itimpi]

All of your options look viable so it will be a time/risk tradeoff.

 

If you can afford the array downtime it would probably be quickest to assign both 18TB drives to parity1 and parity2 and build them in parallel while in Maintenance mode.     I mentioned maintenance mode to ensure no array updates happen while building the new parity which means the old 14TB parity remains valid.  While this is going on keep the old parity1 intact just in case an array drive has problems as this gives a fall-back path.   On completing the move to 2 x 18TB parity drives the old 14TB parity drive can now be assigned as a data drive.

 

If you cannot afford the time in maintenance mode then your third option looks safest as you would have a valid parity drive throughout.

 

An option you have not mentioned which is the quickest is to use the Tools->New Config to allow you to assign both 18TB drives as parity and the 14TB drive as a new data drive and then build the new parity based on the new drive configuration.  The downside of this is that a failure of a data drive before the new parity is built could lead to data loss.  

 

Note that Unraid will not allow you to combine making changes to parity drives and adding data drives at the same time if you have not gone the New Config route.

 

[Ollie]

8 minutes ago, itimpi said:

All of your options look viable so it will be a time/risk tradeoff.

 

If you can afford the array downtime it would probably be quickest to assign both 18TB drives to parity1 and parity2 and build them in parallel while in Maintenance mode.     I mentioned maintenance mode to ensure no array updates happen while building the new parity which means the old 14TB parity remains valid.  While this is going on keep the old parity1 intact just in case an array drive has problems as this gives a fall-back path.   On completing the move to 2 x 18TB parity drives the old 14TB parity drive can now be assigned as a data drive.

 

If you cannot afford the time in maintenance mode then your third option looks safest as you would have a valid parity drive throughout.

 

An option you have not mentioned which is the quickest is to use the Tools->New Config to allow you to assign both 18TB drives as parity and the 14TB drive as a new data drive and then build the new parity based on the new drive configuration.  The downside of this is that a failure of a data drive before the new parity is built could lead to data loss.  

 

Note that Unraid will not allow you to combine making changes to parity drives and adding data drives at the same time if you have not gone the New Config route.

 

 

Thank you for the fast feedback!

Just to clarify, going your first suggested route (maintenance mode) takes everything offline. But doing the other option - adding one drive to make it parity 2, then replacing the smaller parity drive - would allow the server to continue to function as normal? Or should I still stop my docker containers throughout that process (ie could Plex continue to run while parity 2 builds, then while parity 1 is built on the new parity 1 drive (since parity 2 is now valid)?

[itimpi]

5 minutes ago, Ollie said:

But doing the other option - adding one drive to make it parity 2, then replacing the smaller parity drive - would allow the server to continue to function as normal?

 

It would continue to function as normal, although performance might be degraded if there is much other disk activity at the same time due to drive contention.  If there is only light disk activity then it may be more convenient to leave everything available running as normal.

[Jaybau]

Just went through the process (replacing smaller parity drive with larger parity drive, and then moving the old parity drive to data), and it was confusing and didn't go the way I wanted.  I wanted the safest and easiest option. 

 

What I have right now is a full/clean parity sync, while the old parity is sitting unassigned.  However, my array is online, so the old parity is obsolete.  This doesn't sound like the safest, nor the easiest option.

 

I thought I could do a parity copy.  I thought Unraid would have something built-in to copy the parity bits from the smaller drive to the larger drive.

 

If parity copy is not possible, then Unraid could do both Parity 1 and Parity 2.  Then when Parity 2 is complete, remove Parity 1 and move drive to data; Parity 2 drive now becomes the Parity 1 drive.

 

In the future I hope Unraid has scenario buttons that walk the user through the process for common different scenarios.

 

 

 

 

 

[JorgeB]

23 minutes ago, Jaybau said:

Then when Parity 2 is complete, remove Parity 1 and move drive to data; Parity 2 drive now becomes the Parity 1 drive.

That's not possible since parity2 is calculated in a different way, they are not interchangeble, but you can add parity2, remove parity1 and use only parity2.