Trying to create a pool of 54 mirror vdevs (2TB HDDs) on TN11 consistently fails. There is no traceback, the UI simply displays "An error occurred!" and the pool appears in the Storage->Volumes tabs with "Error getting available space".
Over the weekend, I was able to get a pool of all 108 drives eventually by creating a smaller pool, and extending it two times with smaller batches of drives. If I tried to extend the pool with too many drives, I would actually get a traceback.
This is on tn11, running 11.2-INTERNAL-16. The system has three enclosures: 2x ES24s and 1x ES60. All enclosures are wideported.