How do you tell which zpool version you are running?

This is a question that crops up fairly regularly, as different operating systems support different zpool versions. Fortunately, it’s quite easy to find out which versions you are running – simply run:

 

# zpool upgrade

 

If you want a more detailed readout, including the features of the pool version you have, try:

 

# zpool upgrade -v

 

Your output should look something like this:

 

# zpool upgrade -v
This system is currently running ZFS pool version 28.

The following versions are supported:

VER  DESCRIPTION
—  ——————————————————–
1   Initial ZFS version
2   Ditto blocks (replicated metadata)
3   Hot spares and double parity RAID-Z
4   zpool history
5   Compression using the gzip algorithm
6   bootfs pool property
7   Separate intent log devices
8   Delegated administration
9   refquota and refreservation properties
10  Cache devices
11  Improved scrub performance
12  Snapshot properties
13  snapused property
14  passthrough-x aclinherit
15  user/group space accounting
16  stmf property support
17  Triple-parity RAID-Z
18  Snapshot user holds
19  Log device removal
20  Compression using zle (zero-length encoding)
21  Deduplication
22  Received properties
23  Slim ZIL
24  System attributes
25  Improved scrub stats
26  Improved snapshot deletion performance
27  Improved snapshot creation performance
28  Multiple vdev replacements

For more information on a particular version, including supported releases,
see the ZFS Administration Guide.

 

Or for the more simple command:
# zpool upgrade

 

This system is currently running ZFS pool version 28.

All pools are formatted using this version.