Question about working hard drives being 'updated'

[shark2k]

Sorry I suck at coming up with better names for topics.

My question, out of curiosity, has to do with replacing the current drives that are in the NAS with bigger drives to expand the storage and what happens to the old drives.

So to try and be clearer (if that wasn't) here is where my question is coming from. So if I update my drives from 2TB drives to 6TB drives (to get more storage space), once I replace the last drive with the bigger drive and the resilver process is complete my pool should auto expand (hopefully) to show the new size. The question comes from this part. Since I am taking out the old drives, if I were to put them into a new system and install FreeNAS, would it be possible to import the pool from those drives, similar to how you can import the pool if you have to replace the boot device?

This is really just a question out of curiosity. If it isn't something that is actually doable, it doesn't really matter, just thought it would be cool. However, I don't know if something would change during the resilvering process that would prevent that from happening.

Thanks for any answer and if clarification is needed let me know.

Edit: Corrected volume to pool for correct terminology

-Shark2k

 

[Ericloewe]

Your question is:

• Replace drives one by one
• Import pool from the replaced drives

Right?

Well, that would probably not work. I can see it working in very unusual edge cases (theoretically), but it's definitely not something that's remotely close to viable.

 

[shark2k]

Your question is:

• Replace drives one by one
• Import pool from the replaced drives

Right?

Well, that would probably not work. I can see it working in very unusual edge cases (theoretically), but it's definitely not something that's remotely close to viable.

That is correct. Could you explain why it would not work, if you don't mind? It's for my curiosity so if you don't want to take the time I understand.

I guess more specific (so a more concise answer could be given) would be what is the difference that allows importing the pool if you need to replace the boot device vs the situation I brought up?

Thanks for your response!

-Shark2k

 

[Ericloewe]

The big hurdle is that every drive would have a different version of the pool. Only under very specific conditions would the drives successfully resilver into a working pool - and I'm not sure those conditions are even possible.

 

[Ericloewe]

difference that allows importing the pool if you need to replace the boot device vs the situation I brought up?

The boot pool has nothing to do with your "main" pool. It just contains the OS and config files. Even without a config database, FreeNAS would be able to import your "main" pool. Your data would be there, but you'd have to setup everything you had (shares, mostly).

The "main" pool was never actually touched when you replaced the boot pool. It's still a valid ZFS pool, which ZFS can grab and import.

 

[shark2k]

The big hurdle is that every drive would have a different version of the pool. Only under very specific conditions would the drives successfully resilver into a working pool - and I'm not sure those conditions are even possible.

Thanks again for the response. Really do appreciate it.
Looks like I should read up about ZFS pools to help better understand how they work and why it wouldn't be possible to do what I asked. Even though it was just a thought, would be interesting to better understand the reasons why it more than likely wouldn't work.

-Shark2k