I have just ordered 8 1TB drives for my NAS. I am wanting to put them ALL into a ZFS pool. I know what I install TrueNas scale, it will want 1 of those drives for the OS. It seems like a waste of capacity to remove 1/8 of my raw capacity for the little bit TrueNas needs. If I am unable to get an SSD into my Dell PowerEdge R720 (Thinking where the DvD Drive is) I want to try and netboot it.
Is this a crazy idea… Am I Crazy???
You have a bit of a chicken-and‐egg conundrum. Network booting something means the boot image is stored on a NAS/SAN of some kind. If this is your secondary NAS then maybe… Even then, you normally want your NAS to be self contained and able to function without depending on any other devices.
With older FreeNas you could reliably boot from a USB drive, and setup automatic backup of the config file to the pool, so that recovery of the boot drive failure is fast and easy. You could even pre-prepare one or two spare boot flash drives, so you would just plug another one in in case the original fails to boot.
I hope the new TrueNas retained ability to boot reliably from USB (i.e. does not write too much to the boot drive).
Well, TrueNas Documentation states
“You do not need an SSD boot device, but we discourage using a spinner or a USB stick. We do not recommend installing TrueNAS on a single disk or striped pool unless you have a good reason to do so. You can install and run TrueNAS without any data devices, but we strongly discourage it.”
A better option would likely be either SD card (the 720s I’ve seen have a pair of them so you can mirror for TrueNAS, though they still don’t recommend that) or a PCI-E slot-connected SSD of some sort. You could even go a halfway house and use a USB enclosure for an NVMe drive to boot from, removing the issue of USB thumbdrive write wearing.