Can't add another drive "Duplicate serial numbers"

[artlessknave]

It'd be cool if you could partition half of it for boot, half for storage and then raid it.

why? just mirror your boot pool. built in function, handled for you, with GUI buttons. 2 small SSDs is like, maybe 100$? and since you will be dramatically under-provisioning them, they are unlikely to die in your lifetime. hell, in your descendants lifetime maybe.
again, using resources to increase reliability, because, again, remember, ENTERPRISE PRODUCT.

if you have followed anywhere even close to the recomended hardware, you have a system thats probably 800-1500$, plus fairly likely double that in spindle disks, and you are worried about .1% of that in "wasted" storage.

this "Wasted space" thing seems....just so silly honestly. its maybe 100GB (ok 200GB if you mirror it). its *nothing*.
you can get get 128GB RAM STICKS. and put 8 of them in a server.
M$, for example, wastes GB after GB for useless crap on a regular basis. im fine with allocating extra a negliglble amount of space to make my life easier.
ALL of my windows installs are about 80GB, usually on 120 or 240GB disks, because that's whats cheapest. windows and installed apps. everything else (media, games, random downloads and experiments, etc) is on other drives or my high reliability truenas. if windows dies, i reinstall it, nice and fresh.
if the drive dies....i replace it and reinstall windows.

if you want to do any of this, truenas is just not the way.

 

[MorMadness]

this "Wasted space" thing seems....just so silly honestly. its maybe 100GB (ok 200GB if you mirror it). its *nothing*.

This might be your opinion and however it might not be to others. Not everyone can or have the pleasure of having drives around. Wasted space is just that, wasted. if you could use it why not?? and losing 168GB on mirrored drives for 2x16GB boot drives is honestly a waste.

for example, wastes GB after GB for useless crap on a regular basis. im fine with allocating extra a negliglble amount of space to make my life easier.
ALL of my windows installs are about 80GB, usually on 120 or 240GB disks, because that's whats cheapest. windows and installed apps. everything else (media, games, random downloads and experiments, etc) is on other drives or my high reliability truenas. if windows dies, i reinstall it, nice and fresh.
if the drive dies....i replace it and reinstall windows.

Honestly this is a bad analogy. you use windows, installed programs and both of those use that disk space to grow and retract constantly. Windows and actual desktop installs of Linux require big hard drive space. The boot drive of TrueNAS stays static in size for the most part (unless you update) which is why you only need a 16GB drive that will last you a really long time. I haven't switched from 16GB boot section for going on 10 years now. I have switched methods and drives however I still only allocate 16GB to my boot image.

while I agree FreeNAS was for the masses, TrueNAS has moved away slightly. TrueNAS can be used for little home systems with no money and 2 drives however is more suited for massive enterprise structures.

With that said I agree that using 120GB SSD for a boot partition is a waste. So I VM TrueNAS with VMware and can allocate any size boot volume I wish, and I give it only 16GB. For the OP and others that can't or don't want to get more drives however want to see what the hype is about, then run a VM. There is not just one way to do something and just because you don't agree doesn't make it wrong or that it can't be done.

120GB NVMe drive install VMware Free (ProxMox or NG) and 16GB goes to VMWare and 103GB goes to DataStorage where you can create a 16GB VM for TrueNAS and boot off that. This now leaves you with roughly 185GB to use as a data drive within TrueNAS. Now before you go flaming me that this is not ideal because there is no redundancy and it wasn't designed like this and yadda yadda yadda, I agree, however it can be done to test and not waste Hard Drive space and answers the OP's question.

There is not just one way to do something and just because you don't agree doesn't make it wrong or that it can't be done. to say that the system wasn't designed to run like that, is a true statement however doesn't mean it wont work. Can you drive a lambo offroad?? sure can however it wasn't designed for that and you will get the best performance if you drive it on a paved road.

 

[jgreco]

This might be your opinion and however it might not be to others. Not everyone can or have the pleasure of having drives around. Wasted space is just that, wasted. if you could use it why not?? and losing 168GB on mirrored drives for 2x16GB boot drives is honestly a waste.

Then for chrissakes, buy appropriately sized boot drives.

it can be done to test and not waste Hard Drive space and answers the OP's question.

Yes, it can be done, but it's dangerous, foolish, and is likely to cause significant future problems. It's not supported, not what the developers intend, and is a problem here on the forums because people conveniently forget to mention that they've butchered their system in some unusual way before complaining that the bad thing that they were told not to do but did anyways did in fact bend, fold, spindle, and mutilate their bits on them.

This thread is being closed because in the dozens of times this discussion has been held over the years, it has never gone anywhere meaningful. It's open source. You CAN do as you please. Doesn't make it a good idea. Further discussion of your opinions to the contrary are not really productive.