How to replace a disk within a parity space

Question

I have been searching the net for better documentation on this, but so far not a lot of information on what happens when I want to do the following (this is for home use - I am not a storage admin):
I had a JBOD array with 8 disks in it.  3x3TB and 5x2TB.  I had this array thin provisioned to 45 TiB.  When I hit about 13 TiB of storage, the drive stopped accepting new data and it was time to expand.  This made sense to me as I had
about 19 TB or 17.3 TiB of room, minus parity, I'm about there.  Perhaps I could have done more to maximize usage, but that point is moot now.  What I did was buy and add a new 4TB disk to the array.
I had a Storage Pool containing all my disks, and I added this new 4TB disk to the pool.  I had a Virtual Disk sitting on that pool in Single Parity mode.  After adding the drive, I was unable to get the existing virtual disk to use that drive. 
I imagine this was due to the number of columns previously allocated to the array.  I had some ideas on how to offload the data into a new Virtual Disk with more columns, but nothing really worked, so I bought 3 more 4TB disks, reduced my data footprint
to 12TB, copied everything off, and destroyed the array.
Next I re-built my media server and put the original 8 disks in place, along with the fourth new 4TB disk, as well as a 200 GB disk, a 600 GB disk, and a 1.5 TB disk that I had laying around.  I'm in day 2 of my copy operation from BackupDrive1
to the new 12 disk array.  When that completes, I want to use that disk to replace the 200 GB disk I was using as a placeholder.
Everything I read on the internet has been inconclusive to me thus far.  Microsoft's own documentation claims that replacing a disk is as simple as removing the old disk and adding the new one, but I don't think it is.  When I tested this
using the 4TB disk and the other 3 oddballs with a smaller subset of data, it definitely wasn't as easy as that.
My intuition tells me that what I am supposed to do is power down the server and replace the disk I intend to replace, then add that disk to the now degraded storage pool.  At that point I should remove the old drive from the pool and repair the virtual
disk.  However, I am nervous that "removing" a drive will decrease the number of columns, and that in the end I won't be able to use the space from the 4TB drive.  I've seen questions on the net on how to replace a disk and none of them
seem to specifically apply to parity spaces, most are talking about either simple spaces (not happening) and mirror spaces.  I understand the difference but Microsoft's implementation of this is not as straightforward as other products I have used. 
In other cases it was as simple as this: Physically replace disk, receive prompt that your old disk is missing, but you have a new disk, and would you like to rebuild the data from the old disk on the new disk?  Yes?  Then wait patiently while
we painfully write 4TB of 1's and 0's and you're good to go.  I want this button in Storage Spaces please.

Answer 1

Shaon,
Thanks for your reply.  However, this does not sufficiently answer my question.
The 200GB, 600 GB and 1.5 TB drives are temporary drives, since from my experience, adding drives to an array with 8 or more drives does not work.  I want to replace these drives with 4TB drives, leaving the smallest drive at 2TB. 
Also, I was under the assumption that parity (which I'm imagining works in storage spaces somewhat like RAID 50), claims a space for parity equal to the size of the largest drive in the bunch, not the smallest, leaving me with a total space equal to the sum
of the drives minus 4TB.
I have experimented with the suggested workflow, but through the GUI this does not work.  I add the new drive, remove the missing one, and get a popup explaining that my virtual disk will be "In Repair".  However, this popup vanishes before I can
click OK (almost certainly a Microsoft bug).  If I click OK before I finish reading this, nothing happens.  The drive doesn't repair.  I need to retire the disk through PowerShell, and then use PowerShell to repair the virtual disk.  This
works out OK for a while, but once I start using it, the new drive infallibly gives me an error of "Stale Metadata".  I have tried this with 3 different 4TB drives, so I have doubts that this is actually a hardware issue with the drives.  More than
likely, this is a false positive caused by an issue with Storage Spaces.  It does give me pause on continuing to use the disk, so I end up swapping the old 200GB disk back in every time and the space works fine at that point.  Right now I am attempting
to replace the 1.5 TB disk instead, to see if that does anything.  After that, I plan on running the Optimize-Volume -DriveLetter D -Analyze -Verbose cmdlet to attempt to rebalance the data on the disk.  Should I expect that command to do anything
useful?
Just a side comment, this product has been around for a solid 2 years now.  I've found the documentation to be almost non-existent, with the exception of one TechNet page that every question seems to have a link to in the answer.  This page helps
almost no-one as it lacks in examples that apply to the questions that are asked.  It gives little information on parity spaces, and does not equivocally answer the one question that many parity space users have, "What is the correct workflow for growing
my pool?"  I understand that in a mirrored situation, you can't grow the pool without adding a certain amount of disks, but if parity functions anything like RAID 50, this should not be a limitation.  It amazes me that this is the only document Microsoft
seems to have regarding Storage Spaces, and this single document has seemingly never been updated.  Take this feedback however you will, I truly hope that more discussion will reach the right people and help Microsoft fix the issues with a product that
actually has a lot of promise.