Add a New Disk to Old Pool

[themadman]

I am new to this NAS thing. I built one with 3x4Tb drives a few months back with raidZ1... Now I want to add a new 4Tb to that pool. How to do that. Everyone says to use another 7Tb drive to store my existing data and then break it and build a new one which is not possible for me. What to do now.

• Motherboard - MSI x370 gaming pro carbon
• CPU - Ryzen 7 1800X
• RAM - 16GB DDR4 2400
• Hard drives - 3x4Tb with RAIDZ1
• Network cards - Onboard Gbps

 

[Samuel Tai]

What new pool topology are you trying to achieve? It's unclear from your post what your goal is. Are you trying to go from

Code:

        NAME                                            STATE     READ WRITE CKSUM
        tank                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            disk1                                       ONLINE       0     0     0
            disk2                                       ONLINE       0     0     0
            disk3                                       ONLINE       0     0     0

to

Code:

        NAME                                            STATE     READ WRITE CKSUM
        tank                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            disk1                                       ONLINE       0     0     0
            disk2                                       ONLINE       0     0     0
            disk3                                       ONLINE       0     0     0
            disk4                                       ONLINE       0     0     0

or

Code:

        NAME                                            STATE     READ WRITE CKSUM
        tank                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            disk1                                       ONLINE       0     0     0
            disk2                                       ONLINE       0     0     0
            disk3                                       ONLINE       0     0     0
          spares
            disk4                                       ONLINE       0     0     0

 

[danb35]

RAIDZ expansion is Coming Soon™, but not yet present in TrueNAS, and not likely to be there in the next year. That means that the only way to turn a three-disk RAIDZ1 into a four-disk RAIDZ1 is to destroy the pool and recreate it. This, incidentally, is one reason commonly given to recommend mirrors rather than RAIDZ for home and smaller users.

 

[themadman]

Code:

        NAME                                            STATE     READ WRITE CKSUM
        tank                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            disk1                                       ONLINE       0     0     0
            disk2                                       ONLINE       0     0     0
            disk3                                       ONLINE       0     0     0
            disk4                                       ONLINE       0     0     0

-Creating spares VDev is easy... I want to do this... But I don't have spare drives to backup and destroy my pool....

 

[Heracles]

The worst thing to do would be to create a single drive vDev and add it to your pool. That would ruin your pool's redundancy and the only way out would be to destroy the pool.

The second problem is that you have no backups and you declare yourself unable to do any. No server, TrueNAS or other, can be more than a single point of failure. See my signature about backups....

Once your backup solution will be in place, to destroy the actual pool and re-create it should be easy, just like any other modification that would be required.

 

[danb35]

But I don't have spare drives to backup and destroy my pool....

Then you will be unable to do what you're trying to do. Please, before doing more damage to your system, and putting your data at more risk, take some time to learn what you're working with.

 

[themadman]

Please, before doing more damage to your system, and putting your data at more risk, take some time to learn what you're working with.

Can you tell me what kinda damage you are talking about?

 

[Heracles]

Can you tell me what kinda damage you are talking about?

The kind of damage I warned you about...

The worst thing to do would be to create a single drive vDev

Because...

That would ruin your pool's redundancy and the only way out would be to destroy the pool.

Because you are unable to loose it all as of now, you must be extra careful because some mistakes that would have been recoverable in a proper environment are not anymore in yours.

So indeed, be extra careful until your backup plan is in place...

 

[danb35]

Can you tell me what kinda damage you are talking about?

"More damage" does suggest that your system is already damaged, and that was a bit of an exaggeration. But what isn't an exaggeration is that it's configured, well, sub-optimally, and that isn't really going to change unless and until you understand a bit more about how the system is designed to work. In particular, if you take the only path there is to adding a single disk to your pool, you do what Heracles describes, which is to destroy the redundancy of your pool--when that disk fails (and fail it will, eventually), you'll lose everything on the pool.