Users new SSDs for replacement are slightly smaller. Seeing if either of you have suggestion for replacement method other than my, ‘Completely start over with new pools and drives’
We will have to see if they respond. Tagged them since they have already posted in the thread
@charlie20231 First of all, “Ouch!” 40GB short on the new drive.
Silicon Power SSD’s, yes I have one as well. It still works but it is a very cheap device.
Your best bet may be to just
The other option which I doubt you will want to do is to purchase 4TB SSDs and use those.
This topic has hit home for me as I’m finalizing my NVMe NAS. I had to check on my partitioning of the drives to verify they all have a 1GB first partition. Well 3 of the 5 drives do. I will be rebuilding the pool but first creating a larger partition on each drive, I’m just not sure what is safe. Do I use 40GB, 100GB?
Now for pulling something out of my rear (likely will not work):
What version of TrueNAS are you running right now? If it is Dragonfish or earlier, you might be able to set the SWAP Space to 0 (zero) and try to replace the drive again. Try it using an unused new SSD just incase the first drive you tried has a partition already and messes something up. I really doubt you will get back enough space and I honestly have no idea if TrueNAS is looking at the drive size or how large of a partition it can create.
You can run blkid -o list to list all your partitions on your drives. If those drives have been there for a while, odds are they have 2GB swap partitions. This doesn’t help you, it just shows you that prior to EE, swap partitions were created by default. But if you are running Dragonfish you can try the zero value. You can also upgrade to Electric Eel where swap partitions are gone entirely, however if a zero value for the SWAP partition fails, switching to EE is very unlikely to help. But if you are on EE now, well I’m fresh out of easy to do ideas.
i have recently upgraded to Electric Eel 24.10
I just had a thought, the thing i’m most worried about is the network controller app as that is a pain to get re-set up so could I use a spare old disk to create a new pool (single disk) to which I move the apps to. Once I’ve done that I go into settings and on the main pool I do the export/disconenct but do not click the option to destroy data on this pool or delete saved configurations from Truenas. once the pool is exported, power off the machine and put in new drives and re-create a pool and the datasets (not sure if I would be able to use the same name) will I be able to use the restore option to create the shares/pools for me again? once that all working I can then change the apps pool back to the main storage pool and export the pool that I created for the apps.
My thought process with this way if it will work is:
Would doing it this way work?
Follow what Joe said & hope, otherwise get drives that aren’t smaller 
If I had to think of a VERY stupid solution:
Using a second system have a TrueNAS install (USB is fine, it is temporary) & connect the smaller replacement drives to it.
Create a pool with the same name & copy all the files from the original pool to the second system.
Power down both systems, move the drives over from second system to original, remove original degraded drives.
Hope that on boot of original system TrueNAS cleanly imports them & there are no additional checks outside of the pool name so everything that relied on the original 2 bigger drives still is looking at the correct directories & gets the files it needs to work automagically.
…That is a really lazy & hacky workaround & I hope someone gives you better advice. I’d say it might actually work though.
Yeah, it didn’t occur to me that even though the box says 2tb, the drive brands may be slightly different, e.g., 1 is 1.9tb, and the other is 1.95tb, until it was mentioned here.
Yey for over provisioning & confusing marketing!
SOMETIMES - manufacturer software lets you change the over provisioning of space on SSDs; ie increasing/decreasing the amount of space that is hidden from the system to is used to increase performance/longevity of the drive.
…Others time they only let you increase over provisioning or restore it to manufacturer defaults.
Generally you’re SOL.
**disclaimer, over provisioning does have positive uses. IE: longevity & performance benefits by having space that system can’t write to, but that the controller of the drive does so it can do whatever magic it needs to make it happen.
I think @Fleshmauler has a good idea…
If you have a computer that has enough storage on it, you could create a USB flash drive, load it up on the second computer, setup a pool with the same name, and then replicate from your TrueNAS to the temporary TrueNAS. As I understand it, the replication will be basically an identical copy. Then you could export your pool, power down, install new drives, create the new pool, and replicate back to your new drives.
I would recommend you read about it before doing anything. Do not take my word for it, do the research, you have time, nothing is failing.
Honestly, I personally would move as much data off the TrueNAS system, saving it somewhere safe before the replication. Moving the data reduces how much data you need to transfer. The slow part about the transfer it you network connection speed.
I actually like this idea if you have a drive you could use for storage.
The risk you take is really minimal as you will be removing the original drives and you will set them to the side for a few weeks or longer. If something goes wrong, you can put those drives back in and restore your TrueNAS backup configuration file that you will generate before starting all of this.
So read my friend, read about replication.
@joeschmuck @awasb @Fleshmauler
Do you think this way would work?
If Joe says my idea isn’t stupid - then it, amazingly, should no longer be considered stupid.
To be also fair to myself, I don’t normally recommend things that I think don’t have a >50% chance of actually working.
I thought I’d give my try a go and started by using a spare cheap drive and created a pool to move the apps to but that didn’t work, the apps failed to move over to the new pool so that idea is out of the window 
managed to get them back by going to apps → configuration → choose pool and selecting my original pool
You used replication ? I will need to look into it more because I am fairly certain you can create a full blown copy, I thought it included the applications as well.
no i literally just used a spare drive on the same system to create a new pool that I could move the apps to.
My thinking being I could then delete the main pool, remove old drive and add new drives and re-creates shares and datasets and then move the apps back to the main pool.
I must have been wrong, but I could swear someone posted about being able to replicate it all to a backup server where that server could run those apps. Maybe I mis-understood. I’m not the brightest bulb at times.
You should be able to move the apps then.
From what I’ve read, that should move all your apps to the new pool. If you do this, I have no idea how long it takes, I don’t know how much data is in tour apps area. Might want to let it run for a while.
Let me know if this does it. But this isn’t the same as migrating from one server to another. I suspect this will remove your apps from the pool. You might be better to find out how to backup the apps you have, I wouldn’t be surprised if someone has tried that already.
Worst case, how difficult is it to just recreate the apps you have?
Thinking about what you might be doing… If you offload the apps to a seperate pool, you may be able to use that in another system. I just have no idea if you could add them to a new pool on a different machine.
I’d give it a try for you however I have one Core and one Scale system, not two Scale systems, so not compatible.
Yeah, im going to try moving my apps to a new pool again as I think I tried it the first time I didn’t wait long enough after.
Some of the form posts I have read said that the IX-applications dataset cannot be replicated using the replication to another server feature within truenas scale but those posts were quite old so that may have changed on the latest version of scale.
Its the ubiquiti unifi controller app that I am most worried about. its a pain to re setup as I might have to factory reset all the access points, I have however created a backup using the in-app backup feature so I’m hoping if it comes to it I should be able to just use that and restore the app.
Update
Tried moving my apps again to a new Pool on a spare SSD on the system and apps are not migrating over to the new pool. When I click the choose pool button and select the new pool I don’t get any errors when looking at job history but when searching ti seems others have had the same issue.
Are you stopping all the apps before you attempt to move them?
yes stopping all the apps before. do you have to click unset pool before you then click choose pool?
I am on Core and don’t run any apps or VMs. Maybe someone else will answer later
