Re: how to tell if TRIM is working

On 5/3/2024 11:16 AM, Antony Uspensky wrote:
> On Fri, 3 May 2024, Warner Losh wrote:
>
>> Ah yes. You need to enable ZFS trim.
>
> Do you mean autotrim property? No, better to run zpool trim manually.
>
>> The other trim destroys all the data on that partition.
>
> Not always. It sends TRIM subcommand.

I notice that with trim -f <device>, it makes a very large difference in 
performance for certain consumer drives (WD Blue vs Samsung for example) 
that had a lot of writes/deletes.  On FreeBSD, I am not able to restore 
write performance to reasonable levels unless I do a device level trim 
of the entire disk with trim -f. 
(https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277992).  I am still 
trying to figure out why / where this is the case.

     ---Mike


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> A.
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