Favorite ZFS feature(s)?

Some people use ZFS for specific feature(s) that other file systems either don’t have. Or have the feature in a limited fashion.

Here are my favorite features:

  • Check-summing of data, (and metadata)
  • Scrubs verifying checksums
  • Easy Mirroring
  • Verification that Mirroring is working, (another part of Scrubs)
  • LZ4 data compression
  • Easy cloning of my OS pool, (using ZFS Send & Receive)
  • Snapshots
  • Clones

The last 2 facilitate my Linux alternate boot environments. Makes updating those computers much more reliable. If an update goes bad, I can boot back to the prior boot environment and get back a working computer. Have to do this perhaps once a year, (out of 4 computers, not including TrueNAS). Have not needed to resort to full restore in a while.

What are your favorite ZFS features?