Best way to increase pool size

[eng]

Hi,

I could not find an answer to a seemingly simple question.

My case:
i have "main" pool with 1 VDEV MIRROR with 2 3TB HDD.

What I want:
Replace both 3TB HDDs with new 8TB HDDs
* I would not like to create a new VDEV


As I understand it, there are two ways to do it.

First way:
1. Replace first HDD
2. Wait for the end of the resilver
3. Replace second HDD
4. Wait for the end of the resilver
5. Make "Expand pool main"
6. enjoy

Second way:
1. in "Pool Status" choose "Extend Vdev"
2. Add both new 8TB HDD
3. Wait for the end of the resilver
4. Detach both old 3TB HDD
5. Make "Expand pool main"
6. enjoy

The questions are as follow:
1. Is the second way correct and safe?
2. Is it correct that the first way will take longer (perhaps twice as long) than the second?
3. Maybe there are other ways to do it quickly and correctly?

 

[jgreco]

1. Is the second way correct and safe?

Yes, you can replace both disks at the same time. Be sure that both of them resilver completely before making any changes.

2. Is it correct that the first way will take longer (perhaps twice as long) than the second?

It's basically dependent on I/O speed.

3. Maybe there are other ways to do it quickly and correctly?

You could always make a new pool. Pros: less fragmentation. Cons: lots of screwing around.

 

[eng]

Yes, you can replace both disks at the same time. Be sure that both of them resilver completely before making any changes.



It's basically dependent on I/O speed.



You could always make a new pool. Pros: less fragmentation. Cons: lots of screwing around.

Thank you so much for the quick response!

 

[NickF]

Hi,

I could not find an answer to a seemingly simple question.

My case:
i have "main" pool with 1 VDEV MIRROR with 2 3TB HDD.

What I want:
Replace both 3TB HDDs with new 8TB HDDs
* I would not like to create a new VDEV


As I understand it, there are two ways to do it.

First way:
1. Replace first HDD
2. Wait for the end of the resilver
3. Replace second HDD
4. Wait for the end of the resilver
5. Make "Expand pool main"
6. enjoy

Second way:
1. in "Pool Status" choose "Extend Vdev"
2. Add both new 8TB HDD
3. Wait for the end of the resilver
4. Detach both old 3TB HDD
5. Make "Expand pool main"
6. enjoy

The questions are as follow:
1. Is the second way correct and safe?
2. Is it correct that the first way will take longer (perhaps twice as long) than the second?
3. Maybe there are other ways to do it quickly and correctly?

Option 3 is make a new pool and do a ZFS Send/Receive. It solves the problem @jgreco mentions and you dont have to muck around. :)

 

[Dice]

and you dont have to muck around

Adding that there is a bit of mucking around, in case there is a lot of configuration dependent on the old pool name.

In essence, once the data is migrated to the new drives, it is a little juggle of exporting / renaming / importing, which allows you to save work on re-adjusting share names etc.

How To Rename a ZFS Pool

Latest Version: https://forums.truenas.com/t/howto-rename-a-zfs-pool/130 -- The basic process to rename a ZFS pool is to export it from the GUI, import it in the CLI with the new name, then export it again, and re-import it in the GUI. I find I...

www.truenas.com

 

[NormanNeu]

Second way:
1. in "Pool Status" choose "Extend Vdev"
2. Add both new 8TB HDD
3. Wait for the end of the resilver
4. Detach both old 3TB HDD
5. Make "Expand pool main"
6. enjoy

Instead of detaching both old 3TB HDD I guess they could be left inside and a new pool could be created, right?

 

[NormanNeu]

Hi, I am trying now version 1 :
First way:
1. Replace first HDD
2. Wait for the end of the resilver
3. Replace second HDD
4. Wait for the end of the resilver
5. Make "Expand pool main"
6. enjoy

I shut down the system. replaced one hdd. booted. now there is no resilvering process starting automatically as I expected. What did I do wrong?
thanks in advance..

 

[Davvo]

You have to software-replace the drive.

 

[NormanNeu]

hi, thanks. so i went into storage/pools/pool status, i chose the disk that I want to replace, clicking on the 3 dots, selecting replace, that leads to a popup asking me to specify member disk but as the new disk is not connected there is no option to choose from. soplease, could you give me another hint here? thanks

 

[danb35]

What did I do wrong?

You didn't tell ZFS that the new drive was supposed to belong to your pool. Disk replacement is done through the GUI, and explained in the docs:

Disk Replacement

Describes how to replace a disk and restore the hot spare in TrueNAS CORE.

www.truenas.com

 

[Davvo]

hi, thanks. so i went into storage/pools/pool status, i chose the disk that I want to replace, clicking on the 3 dots, selecting replace, that leads to a popup asking me to specify member disk but as the new disk is not connected there is no option to choose from.

If you phisycally replaced one drive with another you should have a new drive there! One of your pools should be in a degraded state.

 

[bal0an]

In my case (13.0-U6.1) the replace UI window does not offer any non-member disks to choose from. Obviously the new disk does not belong to the pool yet. I think the dialog window may be broken.

 

[Davvo]

In my case (13.0-U6.1) the replace UI window does not offer any non-member disks to choose from. Obviously the new disk does not belong to the pool yet. I think the dialog window may be broken.

Check whether the new drive is properly powered.

 

[bal0an]

Check whether the new drive is properly powered.

I can smartctl and add/remove the new disk as a spare drive to the pool. I am thus pretty sure it is powered and connected.
See https://www.truenas.com/community/t...rking-disk-without-degrading-the-pool.116539/ for details.