[talk] ZFS v UFS on APU2 msata SSD with FreeBSD

[Felix J. Ogris]

Hi,

I have been running FreeBSD with ZFS on a Crucial mSATA SSD for 4.5 years now. Started with an APU, I recently upgraded to an APU2. Smartctl reports 34 power cycles, and more than 36700 power on hours. My APU/2 runs the latest FreeBSD amd64 12-RELEASE and serves as a typical dialup router with ppp, pf, ftp-proxy, isc-dhcpd, and named. It also runs musicpd to stream Internet radio and MP3s to internal clients, as well as samba, nginx, and avahi-daemon to stream TV shows recorded by webcamd+tvheadend to our TV set. For fun, ctld exports one ZFS volume via iSCSI to an occasionally powered on VM on a Linux box running qemu+kvm.
ZFS ARC compression fluctuates around 1.7:1 to 1.8:1. Currently, 90 megs of RAM are free, while 150 are swapped out. Swap behavior on FreeBSD 12 seems to have improved compared to 11, where >1000 megs of swap accumulated over runtime. For me, ZFS is a must on such a small and loaded machine, which runs 24/7. Snapshots give me incremental backups; haven't had any inconsistency issues nor long fsck checks after a power reset; the periodic zfs scrub notices me when it's finally time to buy a new SSD.
Despite PC Engines asks users of FreeBSD based operating systems to use the legacy BIOS, I successfully flashrom'ed v4.9.0.5. However, the APU2 or more likely the em driver seem to very picky about network cables. I had no luck with old CAT5 cables or when selecting 100 MBit link speed manually. Use CAT5e cables at least and make sure autoneg works on all connected devices.

HTH,
Felix