The other day I finally received some new disks for storing my data. This originally came about because one of my disks was showing 2 unreadable sectors. I know that doesn’t inherently mean that the disk is about to fail, but you know. Better safe than sorry. Anyway, I ended up looking up a couple ways to move all of my data it seemed like the most widely recommended method was this:

  1. Make sure the system dataset off the pool I am wanting to move off of, and make sure it is not on the pool I am going to.
  2. Make config backup to use later.
  3. Take a snapshot of the Old-Pool.
  4. Create a new pool with the new disks.
  5. In the CLI, use zfs send | zfs receive to send the snapshot to the New-Pool
  6. Once that is done, export both Old-Pool and New-Pool.
  7. Rename and import New-Pool
  8. Verify all data is there
  9. Restore the config to make sure all the shares were back.
  10. Destroy Old-Pool and deal with the old disks.

Doing it

This was interesting because when I had originally ordered the new disks, I thought it would be easier to add the disks to a new vdev instead of a new pool, but being fairly new to zfs and TrueNAS, I did not understand that it did not work that way. Though that is what I did and quickly realized that I could not then remove them… Look, I just said I was new to this kind of stuff.

Anyway, I had to order more disks then properly make the new pool. I was nervous when moving the data for basically no reason because this was more like a copy not a move, but whatever. 20 hours or so later, I did the rename and import and left the New-Pool connected and running for a week before I determined nothing broke. Then destroying Old-Pool made me nervous because while it had not been active for over a week, I was still thinking something could go wrong. Murphy’s Law and everything. After that, I was able to move the disks that were in the second vdev over to New-Pool and now I have it set the way I intended it to be from the beginning.

This was certainly a learning experience, but not as bad as I thought it would be. I do wish I had done some sort of trial run with data that didn’t matter before jumping in with all my personal photos and whatnot.

The next thing I will have to deal with is migrating from TrueNAS Dragonfish to Electric Eel. Primarily the apps moving from kubernetes to basic docker. That will have to wait though. Thanks for reading and if you have any tips, let me know.

Resources:

https://www.truenas.com/community/threads/howto-migrate-data-from-one-pool-to-a-bigger-pool.40519/ https://www.truenas.com/community/threads/migrate-pool-data-to-new-pool.97214/