OPNsense 19.7.1 is out, ZFS on Linux still has annoying issues with ARC size, Hammer2 is now default, NetBSD audio – an application perspective, new FreeNAS Mini, and more.

We do not wish to keep you from enjoying your summer time, but this

Full patch notes:

Stay safe and hydrated, Your OPNsense team

One of the frustrating things about operating ZFS on Linux is that the ARC size is critical but ZFS's auto-tuning of it is opaque and apparently prone to malfunctions, where your ARC will mysteriously shrink drastically and then stick there.

Linux's regular filesystem disk cache is very predictable; if you do disk IO, the cache will relentlessly grow to use all of your free memory. This sometimes disconcerts people when free reports that there's very little memory actually free, but at least you're getting value from your RAM. This is so reliable and regular that we generally don't think about 'is my system going to use all of my RAM as a disk cache', because the answer is always 'yes'. (The general filesystem cache is also called the page cache.)

This is unfortunately not the case with the ZFS ARC in ZFS on Linux (and it wasn't necessarily the case even on Solaris). ZFS has both a current size and a 'target size' for the ARC (called 'c' in ZFS statistics). When your system boots this target size starts out as the maximum allowed size for the ARC, but various events afterward can cause it to be reduced (which obviously limits the size of your ARC, since that's its purpose). In practice, this reduction in the target size is both pretty sticky and rather mysterious (as ZFS on Linux doesn't currently expose enough statistics to tell why your ARC target size shrunk in any particular case).

The net effect is that the ZFS ARC is not infrequently quite shy and hesitant about using memory, in stark contrast to Linux's normal filesystem cache. The default maximum ARC size starts out as only half of your RAM (unlike the regular filesystem cache, which will use all of it), and then it shrinks from there, sometimes very significantly, and once shrunk it only recovers slowly (if at all).

NetBSD audio – an application perspective ... or, "doing it natively, because we can"

Two new FreeNAS Mini systems join the very popular FreeNAS Mini and Mini XL:

FreeNAS Mini XL+: This powerful 10 Bay platform (8x 3.5” and 1x 2.5” hot-swap, 1x 2.5” internal) includes the latest, compact server technology and provides dual 10GbE ports, 8 CPU cores and 32 GB RAM for high performance workgroups. The Mini XL+ scales beyond 100TB and is ideal for very demanding applications, including hosting virtual machines and multimedia editing. Starting at $1499, the Mini XL+ configured with cache SSD and 80 TB capacity is $4299, and consumes about 100 Watts.

FreeNAS Mini E: This cost-effective 4 Bay platform provides the resources required for SOHO use with quad GbE ports and 8 GB of RAM. The Mini E is ideal for file sharing, streaming and transcoding video at 1080p. Starting at $749, the Mini E configured with 8 TB capacity is $999, and consumes about 36 Watts.