Storage Spaces issues adding drive

I have a 4x 2TB drive storage pool setup with storage spaces under parity mostly used for movies/tv shows. I decided to buy 2 more 4TB drives and add them, but I only have space for 1 more at the moment (only 6 SATA connectors on my MB). After adding it (and appearing successful), it attempted to rebalance but eventually stopped changing the %complete and Storage Spaces eventually crashed. I tried again with my second drive, and the same problem. If I do "get-storagejob" in Powershell, every time i boot up it has 3 jobs (screenshot in linked Imgur album) and 2/3 of them always fail at 42%.
I've tried removing both of the drives that failed to add (crashes), I've tried cancelling the rebalancing (crashes), and many other things but Storage Spaces continues to crash as soon as those 2 jobs reach 42% or I do anything to change something.
Data on the drive appears accessible, but any attempt to view results in eternally spinning progress bars (sometimes a second or two of video before sputtering out). I'm usually pretty good with Google and can solve my own problems but this has had me spinning my wheels for days.
Computer:
OS - Windows 10 Pro
CPU - i7 6700
MB - Z170A PC MATE
Any other details should be in the CPU-Z pastebin if it helps.
http://imgur.com/a/f2ObI
http://pastebin.com/T0SMLrqh

You might try running the powershell command "Update-StoragePool -FriendlyName "[NameOfYourStoragePool]" without first and last quotes. Make sure you run powershell as Admin.

Since you need more SATA connectors, and you're now starting to get serious about hard drive storage, I'd suggest ditching the software route (storage spaces, SoftRAID, etc)_ and getting yourself a dedicated RAID controller. They have their own processors on the card to handle all the RAID processing. Most have some memory on the card as well to make things work more quickly/smoothly.

You'd be surprised how much of a difference it makes. One downside though, if you don't have an options to skip boot roms in your BIOS/UEFI (ASUS does, I'm sure others do) it may increase your boot time by several seconds. An advantage too though, that you can do some management of your RAID from the card's BIOS without having to boot your operating system. (good when/if the OS goes haywire)

Don't get a cheap one if you do decide to go this route. Just about every card under $150 is worthless.

Thanks for the suggestion Railtech. I have tried that before but when I type that it asks me to confirm, I confirm, and then it doesn't say anything else. Not sure if did what it's supposed to, but it still crashes after about 5 minutes like it has been.

Hydranix, from what I understand RAID is very inflexible and has it's own querks. I couldn't find a straight answer on how to simply add a new drive to expand the storage space in RAID not to mention expanding with a *gasp* different sized drive. I wanted something that could grow with me and didn't all need to be on the same raid controller. Regardless, I'll consider your suggestion after I get through this.

One thing I have found on new drives larger than 1 TB is corruption from the factory. Seems quality control has gone down hill somewhat in recent times. I always run chkdsk /r against new large drives to correct any corruption before putting them in service.

Another possibility is sector size. the sector size on disk must be the same on all the drives otherwise you will be unsuccessful.

1. Run msinfo32 in command line that should popup a GUI window called "System Information"
2. In the left pane select "System Summary->Components->Storage->Disks". This should load info of all drives in the right pane
3. Find your desired drive and check the value for "Bytes/Sector". it should list the sector size of each disk

Thanks for your help again Railtech,

After much frustration and trying to unplug each individual drive and restart over and over again in an attempt to isolate any single drive causing the problem, it magically started to repair itself. It must have been a physical connection causing some mysterious error because previously they all showed up as healthy in "Get-PhysicalDisk" powershell command as well as CrystalDiskInfo SMART checks. After the storage space started repairing itself, it also showed up with several new errors in CrystalDiskInfo for one of my oldest disks but is still listed as healthy in the Storage Pool list. I imagine it's starting to fail so I'll remove it as soon as things are repaired and stable.

I'll be sure to run checks on the new drives before I integrate them, but I think the stress of rebalancing caused one of the older drives some issues and somehow that threw everything out of whack. If it had cleanly failed, I suspect the parity could have rebuilt with my new drives, but it was holding on just enough to cause the system to crash over and over again.

Mystery solved, and hopefully updating the storage pool helped.

One more question. These are the results for the drive that started showing a SMART error. Is this in any way recoverable or should it be turfed?

Oh yeah! That drive is toast! Good for a door stop! I notice that this drive is an SATA II drive not SATA III, are you mixing these together in Storage Spaces? If so I would advise against it and if so that could be an underlying factor to the drive failure.

It's one of 2 of my first big drives that is still SATA II so that means there will only be 1 left after this whole process is over. Do you think its important enough to get rid of it proactively?

If it were me I would remove the SATA II drives from the pool and only keep the SATA III drives. The SATA II drive will degrade the drive pool from a performance stand point and because the SATA III drives can handle data much better and faster will cause the SATA II drive to run maxed out all the time thus leading to drive failure and failure of the pool again.

Best to just remove it now and get it over with.