According to various sources, stability of ZFS on i386 boxes is going to be... not a priority. Regardless, I decided to take up the challenge.
My first attempt to get everything stable was to use zero settings in the loader.conf file. That lasted until my first big ports build. That did not work.
A similar (but not the actual: I have received plenty and just chose the last one) error message follows.
panic: kmem_malloc(86016): kmem_map too small: 520044544 total allocated cpuid = 0 KDB: enter: panic [ thread pid 0 tid 100228 ] Stopped at kdb_enter+0x3a: movl $0, kdb_why
This is consistent every time I load the disks heavily (such as trying to copy the entirety of the HEAD svn repository to another directory). Now, my goal is to attempt to get things stable under heavy load. I started using the following loader.conf settings.
# /boot/loader.conf excerpt vm.kmem_size="512M" vm.kmem_size_max="512M" vfs.zfs.arc_max="128M" vfs.zfs.vdev.cache.size="5M"
That did not work. To avoid such quoting throughout, I will refer to such settings in the future as vm.kmem_size/vm.kmem_size_max/vfs.zfs.arc_max/vfs.zfs.vdev.cache.size. Using that the above values would be 512M/512M/128M/5M. Now, since that did not work, and after some IRC goodness on #freebsd, I decided to just try 384M/384M/64M/5M. Now, there is no real empirical reason to use those, but they are close to the 330M/330M/40M/5M which worked when NAStie had 784M of memory, so perhaps this will do the trick.
We will see, now to rsync and compile a lot!
Update: Hrm... after transfering the latest Mathematica download (about 800 MB), and then removing the Mathematica 7 ISO for Mac (I do not remember how much), system dumped again. I am going back to the 330M/330M/40M/5M which worked for me when I only had 768 MB of memory. We will see how that works.
Update: Odd, had a middle of the night shutdown, did not notice until this evening. I will reboot and see what is what. No change in values.
Update: Even odder, I can not get the server to stay stable for longer than (about) a day. Every time I stress the drives it dies (technical term). Going to try moving to AMD64 (more in the new post).