&gt; Other software RAID solutions like Linux MDADM lets you grow an existing RAID array with one disk at a time.<p>His issue isn&#x27;t with ZFS, it&#x27;s that most parity raid (raidz, raidz2, raid5, raid6, etc) doesn&#x27;t support safely rebalancing an array to a different number of disks.<p>With mirrors, the things he describes aren&#x27;t an issue, especially in a home server.  You can start with one disk, mirror it when you&#x27;re ready; then add additional vdevs of mirrored pairs extending your pool as necessary. Or upgrade two disks to grow a vdev.<p><a href="http:&#x2F;&#x2F;jrs-s.net&#x2F;2015&#x2F;02&#x2F;06&#x2F;zfs-you-should-use-mirror-vdevs-not-raidz&#x2F;" rel="nofollow">http:&#x2F;&#x2F;jrs-s.net&#x2F;2015&#x2F;02&#x2F;06&#x2F;zfs-you-should-use-mirror-vdevs-...</a>