What are the downsides to using a small M.2 SSD card to store the FreeNAS OS?

[stevenmw]

The FAQ recommends a 16GB USB flash drive. What would be the downside to using a 16GB M.2 SSD card to store the OS?

Would this work all right? What's your opinion on this?

 

[Apollo]

It should work as M.2 has SATA lanes, so driver should be present under 9.3.
It would definitely be faster, but is it that much of a benefit, probably not unless you host the reporting Database vs. USB.
You may not be able to mirror the boot drive as only one M.2 interface is most likely available. I don't know if redundancy will work between USB and M.2 (it should for ZFS).

 

[cyberjock]

You should be able to setup mirrors between any two devices (for example, USB and SATA) but I'm not sure how "good" of an idea that would be. Besides, the odds of your typical SATA flash drive failing are very very low. I personally wouldn't mirror SATA SSDs, but that's just me.

 

[stevenmw]

It would definitely be faster, but is it that much of a benefit, probably not unless you host the reporting Database vs. USB.

What do you mean host the reporting database?

I do no intend to mirror my OS drive. I just don't have the need to.

 

[Apollo]

What do you mean host the reporting database?

I do no intend to mirror my OS drive. I just don't have the need to.

Reporting database is everything that tracks statistics over time and is used to display graphs of the CPU, disk, network.... on the GUI.
By default I think it is stored on the boot drive, but can be remapped to one of the zpool.

 

[stevenmw]

Oh, I'd definitely host that stuff on the SSD. Do you think a 16GB M.2 drive would be adequate to store the OS and reporting DB?

 

[Apollo]

Oh, I'd definitely host that stuff on the SSD. Do you think a 16GB M.2 drive would be adequate to store the OS and reporting DB?

I don't know the answer to that.
But what I know is that the graphs are being averaged out over time, as the resolution is lost the older the data. This may simply be a display limitation, but I suspect the actual data held in the reports are being phased out. If that is the case, then the space required for the report would be marginal.