I know where the "(Adaptive)" is coming from. Forgot I had added an L2ARC to this box as an experiment and never removed it...
Check out the output...
# python /usr/local/www/freenasUI/tools/arc_summary.py | grep "ARC Size:"
ARC Size: 77.23% 23.16 GiB
L2 ARC Size: (Adaptive) 27.59 GiB
It's grabbing the last line and using it.
For those that want to know how much my L2ARC is used in a home environment...
Code:
L2 ARC Summary: (HEALTHY)
Passed Headroom: 27.25m
Tried Lock Failures: 153.21k
IO In Progress: 348
Low Memory Aborts: 174
Free on Write: 454.24k
Writes While Full: 45.85k
R/W Clashes: 166
Bad Checksums: 0
IO Errors: 0
SPA Mismatch: 107.57m
L2 ARC Size: (Adaptive) 27.59 GiB
Header Size: 0.19% 52.54 MiB
L2 ARC Evicts:
Lock Retries: 361
Upon Reading: 0
L2 ARC Breakdown: 86.61m
Hit Ratio: 11.83% 10.25m
Miss Ratio: 88.17% 76.36m
Feeds: 466.73k
L2 ARC Buffer:
Bytes Scanned: 33.12 TiB
Buffer Iterations: 466.73k
List Iterations: 29.41m
NULL List Iterations: 916.60k
L2 ARC Writes:
Writes Sent: 100.00% 101.65k
See? Utterly useless. Miss ratio of 88%. ;)
ZFS doesn't even really try to use it. A whole 4GB out of a 32GB drive is used (the most I've ever seen it use before).