ZFS + mysql appears to be killing my SSD's

From: Pete French <petefrench_at_ingresso.co.uk>
Date: Mon, 05 Jul 2021 13:15:10 UTC
I hve a netwkr of FreeBSD machines which are running mysql on top of 
zfs. I have been doing this for a while, but a couple of years ago we 
switched to using SSD. After less than a year (I dont remember the exact 
timings), they all strated to fail. We assumed a bad batch, and had them 
replaced, and didnt think anything more of it.

A week or so, all the replacements started to fail. This was shortly 
after I upgraded to FreeBSD 13 and OpenZFS, but I think this is 
unrelated, however its one major chnage which happened before the most 
recent round of failures.

The thing is though, that I am not seieng any heavy activity on the 
drives. The load is sustained, but well below the lifetime write 
thresh-hold for the drive. I also do not see the drives a being heavily 
in use when I run gstat. So its perplexing. I am assuming its related to 
the mysql load, as this is identical across all machines, and they are 
all dying within a few days of each other.

Any insights would be appreciated... :-)