What are your thoughts on "Upgrade Pool"

TrueNAS General
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1

This Option appeared after upgrading to “TrueNAS SCALE ElectricEel 24.10 [release]”
Storage>Upgrade

Upgrade Pool
Proceed with upgrading the pool? WARNING: 
Upgrading a pool is a one-way operation that might make some features of the pool incompatible with older versions of TrueNAS: st4000dm

I get that after this I will not be rolling back to previous backups, I will make new backups if i upgrade.
I do need to use the new features to expand my raidz1 3 drive pool with 2 additional drives which I have already ordered.

So what are your thoughts how risky is this?

sorry i cant link any images

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You already understand the “risks”.

Upgrading a pool is a one-way operation.

The only way to assure you can “undo” an upgrade is to create a checkpoint before you go through the upgrade and RAIDZ expansion process.

Keep in mind that you’re not meant to write any new important data (that you wish to keep)[1] after the checkpoint’s creation, if you plan to immediately rewind back to the checkpoint.

TL;DR:

  1. You create a checkpoint
  2. You upgrade the pool
  3. You expand your RAIDZ vdev
  4. You immediately regret it :scream:
  5. You rewind back to the checkpoint.
  6. Everything from steps 2 through 3 “never happened”

Alternative TL;DR:

  1. You create a checkpoint
  2. You upgrade the pool
  3. You expand your RAIDZ vdev
  4. You like the results :slightly_smiling_face:
  5. You discard the checkpoint

:warning: Understand the nuances of checkpoints, and the differences between importing pools on TrueNAS vs vanilla ZFS.

  1. That’s why if you write new files between steps 2 through 3, you will lose them after rewinding to the checkpoint. ↩︎

1 Like
3

thanks for clarifying,
my confusion arise from the button to extend pool is already present after the 24.10 ElectricEel upgrade then why a second button to update flags, does it mean that i can Extend my pool without upgrading the feature flags, if yes then whats the point of even upgrading the flags.

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An alternative explanation is this:

  • If you plan to go back to Dragonfish or Cobia then DON’T upgrade your pools.

  • If you are 110% certain you will stick with EE then you can upgrade your pools (BUT NOT THE boot-pool) but you don’t have to unless you want to use e.g. RAIDZ expansion.

  • If you want to use RAIDZ expansion, then you need to upgrade that pool, but this then means you cannot go back to Dragonfish.

2 Likes
5

Thanks, reminder that I need to upgrade the pool in my lab. It’s a lab, if things go wrong I burn it down and start from the beginning.

Not sure where to go with my production system right now, still on Core.

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“Extend” and “expand pool” are not the same as “RAIDZ expansion”. They do sound similar, though.

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i mean this
Upgrade button

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Arc_N51t0deUIv1664×818 82.4 KB

the Extend button is on the Manage Device page, this is the one i want to use to increase the capacity of my raidz1 pool.

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The “Upgrade” button basically issues zpool upgrade <poolname>

It has nothing to do, exclusively, with extending a pool or expanding a RAIDZ vdev.

The reason for having to first upgrade your pool is to make those newer features (such as RAIDZ expansion) available to the pool.

1 Like
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After you upgrade the pool to enable the new zfs feature flags, then you can use the Extend button to expand the vdev

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got it, so basically for my requirement I have to upgrade my pool no matter what.
cross fingers, here we go…

1 Like
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it would be nice if there was a way to postpone the upgrade alert (maybe reactivate it when there are even more feature flags to upgrade).

I think it’s somewhat bad practice to pester the user on such an issue. there are legitimate reasons to keep a pool at a specific set of feature flags.

real world, Unraid and TrueNAS core’s ZFS both lag behind TrueNAS Scale’s version.

1 Like
12

Personally, I think it’s time to upgrade any pools using Cobia or Dragonfish :wink:

Are you really going to go back to Bluefin?

Okay… Core… well 13.3 supports the same ZFS features as Cobia/Dragonfish.

So. Upgrade your pools on Dragonfish before upgrading to EE… and then… if you need RaidZ Expansion then it’s time for an upgrade again :wink:

This gets you device removal, block cloning and all the other nice things in OpenZFS 2.2

1 Like
13

So I did upgrade my pool’s, not gonna lie I was sweating head to toe, but all it took was 3 seconds and done.

the process i followed was very simple and as follows:

  1. Made a backup and a snapshot of TrueNAS before upgrade (this would not help since there’s no going back, but gives me peace of mind)
  2. Upgraded the pool (expecting it to last for days, ended up only a 3 second process, lol imagine my surprise), checked the new flags, all good
  3. Made a backup and a Snapshot after upgrade
  4. Restarted TrueNAS and made another set of Backup and snapshots
  5. Running like a charm for 2 days without issues

Thanks TrueNAS team lots of love.