We had a round of thunderstorms at Dismal Manor. Not terribly bad but there were some flashover clearing events. When the dust had settled and the rain had stopped, the singleton boot device on my FreeNAS box was corrupt and FreeNAS would not start.
This is not a big deal as the storage pool is on separate media and all of the metadata to reconstitute the storage pool is in multiple spots in the array devices. FreeNAS would try to start, find system files borked, and fail to start. It clearly diagnosed the problem to the boot media.
How FreeNAS helped
FreeNAS is designed to allow replacement of the boot media and easy recovery of the array. If you make a system configuration save and squirrel it away safely, complete recovery is as easy as replacing the boot media, installing from a thumb drive, and restoring the configuration snapshot. Your shares, jails, VMs, etc are restored.
FreeNAS boot media use the ZFS file system and may be a RaidZ0 device (redundant pair). if one fails, it is likely the other is good. In my case, I had a singleton boot device and the power drama caused a write to go bad, probably stomping on a file not being updated. When the machine restarted, the process using the file trapped
ZFS is one of a small number of file systems that checksum both the payload and the file metadata. This made it pretty easy for ZFS to catch the bad bit and call a crash without creating collateral damage or a visit to the illegal instruction or bus error trap handlers. It knew what was wrong and could say rather than leaving clues to a puzzle.
So, FreeNAS users, visit System -> General and save a configuration. Squirrel away a copy on your cloud storage (iCloud, Google, or MS) that you can reload should recovery become necessary. Update your saved configuration each time you change the system configuration.
You did have a configuration save?
I didn’t have a configuration save so I had to recreate the shares and the VM running Roon Server. This was easy when I first did it in 2017. Well, it is 2018 and Debian and FreeNAS have both been updated. There was a glitch in the FreeNAS VM stuff. It now required hand creation of the guest install root directory. Once past that, Debian 9.4 networking would not come up. Ubuntu had similar problems. CentOS 7 had different problems. I couldn’t get a current VM to run.
The old Mac Mini gathering dust on the shelf is now a Ubuntu 18-04 LTS box running my Roon Server and life is again good.
If you’re not an OS tinkerer
If you’re not a tinkerer, buy the recommended NUC or Nucleus. These products have two big advantages. First, Roon worries about the software, all of it including a Linux distribution tailored to Roon. No apt-getting the dependencies.
The second is that Nucleus is designed to be part of a music player. The premium cost is in the power supplies. Effort goes into keeping both power and ground clean so ground grunge doesn’t creep out to affect attached DACs or receiver/preamps. Those of us home brewing compensate by transformer coupling the SPDIF coax or using TOSlink optical SPDIF.