I have 4 X 10TB drives and would like 2 of them configured as 1 X 20TB and the other 2 as 10TB each
Is this possible?
You'll need to switch to FlexRAID and destroy your existing XRAID volume. It's best to uninstall your apps first.
I suggest making the first disk a 10TB jbod volume (the NAS will use it for /apps and home folders, and the 10 TB JBOD volume is more robust). Though it will also use it for timemachine - if you use that (and need it on the 20 TB volume) then create the RAID-0 volume first (and use the first two disks).
Assuming no need for timemachine, the process is:
select the first disk on the volumes page, and create a JBOD volume.
Repeat that with the second disk.
Finally select the last two disks, and create a RAID-0 volume.
These volumes can't be expanded, so you'll need to destroy them, and create new ones on larger disks if you need to do that. Also, if either disk in the 20 TB volume fails, you will lose the data on the entire volume.
I originally diskpart and cleaned all disks then selected the fist disk for JBOD and it took the other 3 as hostage, I had no control over them.
Something don't look right
I can't give you a step-by-step with screenshots, as that would require me to rebuild my own NAS.
I suggest trying again. Remove the bottom three disks (the volume will fail), and then click on the "Perform Factory Default" control on the system->settings page (in the "Update" section).
After that completes, and you set up the NAS again, change to FlexRAID by clicking on the XRAID button on the system->volume page. The green stripe on the XRAID control should disappear.
Then perhaps remove the partitions on the remaining disks (if you don't, you can format them in the NAS using the format control later on).
Hot-insert one into the NAS, and select it from the volume tab, and create a new volume on it.
Seem to have an error in logs after this configuration
2019-12-12 09:44:58: BTRFS: error (device md126) in btrfs_commit_transaction:2241: errno=-5 IO failure (Error while writing out transaction)
Would this be related to how I configurated the disks?
It's a disk error (write failure). You can see which disks might be involved by looking in mdstat.log. Though there should be another error in system.log or kernel.log that will give you the disk.
What was going on in the system when this error happened?
Not sure what was happinging at the time as it ckecked the logs 2 days after it was logged, Not sure what I am looking for in these logs, how do I upload them?
You download them to your PC from the admin web ui. You don't upload them here (they shouldn't be posted publicly).
You can upload them into cloud storage (google drive, drop box, etc). Then send a private message to the one of the mods here ( @JohnCM_S or @Marc_V ) with a download link, and ask them to analyze them for you.
Generally you'd look in system.log and kernel.log for disk errors and btrfs errors.
