TRIM support for UFS?

[Matthew Jacob]

> BTW. Have you actually observed any performance degradation without
> TRIM? I've similar SSDs and from what I tested it somehow can handle
> wear leveling internally. You can to TRIM entire disk using this simple
> program below, newfs it and test it. Then fill it with random data,
> newfs it again, test it and compare results.

Yes. I've seen performance degradation. It's not clear that TRIM is the 
most useful in all cases, partly because it's generally a very slow 
command and it's not quite clear how well the wear levelling algorithms 
incorporate TRIM changes.

One thing is certainly true is that if SSD drives are for caching only, 
a SECURE ERASE at each 'mount' time along with the appropriate newfs 
helps substantially.