spa history version logging spams console on pool create/import/etc.
zfs - Zettabyte File System
Will spam the console. It should be removed. (or perhaps be a zfs_dbgmsg?)
The code's been there for (relatively) ever.
commit c8e1f6d2e1adb3a8cc413859aaa8c61813665ac6 Author: Mark J Musante <Mark.Musante@Sun.COM> Date: Mon Jun 22 21:15:44 2009 -0400 6842809 zfs history needs to record system info on import/create