Which ONTAP version FILER running (kb is referenced below) ?
Kb states: Starting from ONTAP 9.6, newly created LUNs with the OS type solaris have zero-sized prefix and suffix streams, and lun resize command works as expected.
LUN resize function not implemented for Solaris LUN:
https://kb.netapp.com/onprem/ontap/da/SAN/LUN_resize_function_not_implemented_for_Solaris_LUN
If you are running 9.6 (Means the LUNs were created in 9.6 onwards), then you can re-size it (Before making any changes to the LUN, always have a snapshot so that you can go back to the data point before the resize), if it were created prior to 9.6 then I doubt you could do anything. As per the KB, you could use the workaround to create a LUN with suffix-zero but not the existing one.
Standard steps would be:
From storage side:
1) Grow the volume (resize)
2) Grow the lun (resize)
From Solaris side: (speak to your solaris/unix team, don't take my words)
Here is the doc on how to identify solaris file-system
https://docs.oracle.com/cd/E23824_01/html/821-1459/fsoverview-28729.html
Note: As long as you have a taken a snapshot of the good working filesystem, you can always restore the snapshot and get your system back.