zpool export/import on failover - The pool metadata is corrupted

[mxb]

Hello list,

I have two-head ZFS setup with external disk enclosure over SAS expander.
This is a failover setup with CARP and devd triggering spool export/import.
One of two nodes is preferred master.

Then master is rebooted, devd kicks in as of CARP becomes master and the second node picks up ZFS-disks from external enclosure.
Then master comes back, CARP becomes master, devd kicks in and pool gets exported from the second node and imported on the first one.

However, I have experienced metadata corruption several times with this setup.
Note, that ZIL(mirrored) resides on external enclosure. Only L2ARC is both local and external - da1,da2, da13s2, da14s2

root at nfs2:/root # zpool import
   pool: jbod
     id: 17635654860276652744
  state: FAULTED
 status: The pool metadata is corrupted.
 action: The pool cannot be imported due to damaged devices or data.
   see: http://illumos.org/msg/ZFS-8000-72
 config:

	jbod        FAULTED  corrupted data
	  raidz3-0  ONLINE
	    da3     ONLINE
	    da4     ONLINE
	    da5     ONLINE
	    da6     ONLINE
	    da7     ONLINE
	    da8     ONLINE
	    da9     ONLINE
	    da10    ONLINE
	    da11    ONLINE
	    da12    ONLINE
	cache
	  da1
	  da2
	  da13s2
	  da14s2
	logs
	  mirror-1  ONLINE
	    da13s1  ONLINE
	    da14s1  ONLINE

Any ideas what is going on?

//mxb