I'm currently in the process of converting my main storage pool to ZFSonLinux. I finally (almost) decided that I would like to have an 11 disk RAIDZ3 pool over a 10 disk RAIDZ2 and 2x6 disk RAIDZ2 pool. My question however is: wouldn't it be better to create the pool with ashift=13 (yes, thirteen) if I wanted to add SSD SLOG and L2ARC later? I read (and it seems logical) that for pure SSD pools with modern drives ashift=13 yields better performance because the page size of such drives is now 8k. With ashift=13 the read-modify-write pattern that 4k accesses generate could be avoided, which would reduce IO latency.