Boot mirror and "use all disk space" question

[dkhorak]

Quick question, sorry if it's been addressed, I can't seem to find any concrete answer.

I built my first FreeNAS machine ~6 weeks ago, and used an old, slow 8GB thumb drive as the boot drive. I've since gotten two new shiny 16GB thumb drives (identical model), and want to transfer my boot over to those.

Here's what I'm hoping to do - someone please tell me if this will work.

Boot as usual, using the old 8GB boot drive. Mirror the boot device to one of the 16GB sticks, with the "use all disk space" option ticked. Shut down the system, remove the old thumb drive, insert my 2nd empty 16GB thumb drive, and reboot off the first mirrored stick. Then mirror the two new thumb drives.

Will I then have the full 16GB capacity of the new drives?

 

[Chris Moore]

Will I then have the full 16GB capacity of the new drives?

Yes. Sometimes USB drives are problematic at boot time to pick the drive as a boot drive. That is down to your system BIOS, but what you want to do is absolutely possible and should work with no problem on the FreeNAS side.

Here is the manual page:
https://www.ixsystems.com/documentation/freenas/11.2/system.html?#mirroring-the-boot-device

 

[Chris Moore]

PS. Over the years, I moved from a 8GB boot stick to a pair 16GB to where I am now; booting from 40GB hard drives. I don't suggest using USB boot media, but if that is where you are. It works for some people.

 

[dkhorak]

Thanks for the replies. I'll give it a go then.

On your other point - I had initially planned on booting from a couple tiny SSDs, but (I thought) I kept reading that was overkill, and that data transfers to-from the boot drive so infrequently that USBs would be more than adequate.

 

[Apollo]

@dkhorak, I would rather switch to SSD instead of USB for the following reasons:

- Having mirrored USB boot will not guarantee your system will boot if the primary boot drive fails.
- SSD are nowadays more reliable and have higher endurance rater than USB.
- USB boot drive don't necessarely die due to write endurance issue, but mostly from Read Endurance I believe. Boot scrub occures around every 7 days or so and USB mortality has been pretty high in my case.