I have a physical machine that runs a ZFS pool of six drives. After one drive developed SMART warnings, I removed it, replaced it with a larger drive, and then ran the zpool replace command to resilver the pool.
As the resilvering started, I noted that it was going pretty slow. There...
I regularly update my 2 FreeBSD servers using freebsd-update fetch install and portmaster -a.
Both running as VM on VMWare ESXi v6.5.
After last update both servers are responding extremely slow, especially ssh logins and using su to get root, and SHA256 checksums when upgrading ports...