> Illumos has a way to expand pools ... ZFS creates a vdev inside the new larger vdev Huh? > IDK if that's in OpenZFS yet. The openzfs tree (on github) is vi

> Illumos has a way to expand pools ... ZFS creates a vdev inside the new larger vdev Huh? > IDK if that's in OpenZFS yet. The openzfs tree (on github) is virtually identical to illumos-gate (on github). > physical block addresses should never have been part of the ZFS Merkle hash tree, thus allowing physical addresses to change without having to rewrite every block from the root down. mahrens deals with this (and block pointer rewriting) here: https://www.youtube.com/watch?v=G2vIdPmsnTI#t=44m53s https://www.youtube.com/watch?v=G2vIdPmsnTI#t=44m53s Even with SSDs IOPS are precious. On rotating media, burning track-to-track seeks in reading and updating a large hash table is a bad plan (cf. the deduplication table).