Questions about replacing all of the hard drives

TrueNAS General
1

Hi, everyone,

I purchased 8 -4 TB hard drivesto replace the 5 -2TB drives that I already have. I’ve copied all of the data off of the NAS, so my questions are these:

  1. Do I have to remove the old UDEV before I replace the drives or can I just replace them?
  2. What would be the best option for how to set up the new UDEV on the drives? I have a ZFS striped setup now, but I want to make sure I get the most usable space with the best backup/redundancy that I can.
  3. I have two NVMe drives in the system as well. Should I use one or both of them as a cache for the UDEV? Currently, I have one set up as a cache for the existing UDEV.

Thanks for any help and advice with this. I plan to set it up tomorrow sometime and move my old data back on overnight.

Patrick.

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It would help if you gave better details on your system. L2ARC is probably not necessary. Two identical sized NVMe would be better off as a APPS pool in a mirror VDEV.
You said striped with 5 drives and you want to go to an 8 wide Raid-Z1 or Raid-Z2? If going all one pool, I would do the 8 wide Raid-Z2. Two drives of redundancy and starting with Raid-Z2 will allow you to replace all members with much bigger drives in the future and not have to recreate a pool to move from Raid-Z1 to Raid-Z2. Raid-Z1 isn’t recommended with much larger drives.

Do you have a plan to back up your pool data elsewhere? Pools and VDEVs can fail, etc.

2 Likes
3

Hi, there,

So my system is a FreeNAS-Mini. I’m trying to maximize the space available in it, which is why I went to 8 4TB Western Digital drives instead of the 5 2TB WD Drives that I currently have. In looking at it, I have two 119 GB SSD Drives that are available for pools and a 14GB SSD drive that’s currently in my boot pool.

As for backups, I do have all of the files stored on a couple of external hard drives as well as the NAS. Right now, my pool consists of about 3TB of files, plus 3TB of backups for my other computers. I guess I’m looking for the best options for this. Another thought that I had was to create two pools. One for strictly backups, and one for the rest of my files. And assigning half of the drives to each pool. I don’t foresee filling up the data pool anytime soon, but the backups will probably fill up in a few months.

My main question really is when I swap the drives out, do I need to delete the current UDEV pool first, or should I wait until I’ve swapped the drives out and it “can’t find the pool”?

Thank you for your reply. Have a great weekend.:slight_smile:

Patrick.

4

I am guessing you have a TrueNAS Mini R since you mention 8 drives.
You aren’t being clear on what your current pool layout is and what you are attempting to end up with. What do you mean by swapping out drives? Are you replacing the 2TB drive with a 4TB drive one by one on a Raid-Z2 VDEV and allowing it to resilver until all are replaced, Expanding the pool and then adding the other 3 drives using Raid-Z Expansion to create an 8 wide Raid-Z2 VDEV?
Are you planning on destroying the current pool and VDEV and creating an 8 wide Raid-Z2 to get the most accurate space reporting?

BASICS

TrueNAS Systems pool layout whitepaper
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5

Hi, there,

I have the FreeNAS Mini XL+.On my truenas page, it’s listed as a FreeNAS-mini-2.0 running 25.10.2.1 Community (upgrading right now). I’m completely rebuilding from scratch, as far as my pool goes. I’m replacing all of the drives with the 4TB drives and giving the 2TB ones to a friend. So, yes, I plan on destroying the current pool/VDEV and starting over with an 8-wide pool. I figured that would be easier than trying to replace the drives individually and reslivering the pool.

I’ll read the primer this week and most likely work on this next weekend. I’m not really sure what all information you need.

Have a great night and thank you again. :slight_smile:

Patrick.

6

As long as you just had the hard drives as storage and no Apps nor VMs. Just completely destroy the pool using the GUI and make up a new pool with your new devices. You can chose the erase (destroy) data option on chosing to Export / Delete the pool. If you are worried about the data destruction on your old pool, I would boot your system with something like DBAN or other live Linux version that can do a secure erase on all your old drives.

Then just power off, swap out all the drives, power back up and create your new pool and VDEV