Single disk -> two larger disks mirrored--how?

[danb35]

I have a pool (called, creatively enough, ssdpool) for my jails* consisting of a single SSD. I'd like to both increase the size of the pool, and change it to a mirror. I can think of two ways to do this--not sure if there's any reason to prefer one over the other:

• Using the GUI, replace the existing SSD with one of the larger ones. Once complete, at the CLI (grrr....), add the second larger SSD as a mirror of the first.
• At the CLI, add one of the larger SSDs as a mirror of the existing smaller SSD. Once complete, at the GUI, replace the smaller SSD with the other larger one.

Is there something I'm missing that would favor one of these sequences over the other?

* There's really no good reason for this configuration at this time--in my system, it goes back to when we could have VirtualBox jails, so the jails pool was also storing VM virtual disks. I thought it would benefit performance of those.

 

[Basil Hendroff]

More for my own learning, could the following ways work?

A. Assuming spare ports are available:

Using the GUI:

1. Create a mirrored pool using the larger SSDs.
2. Replicate from the single SSD to the mirrored pool.

B. Assuming only one spare port is available to accommodate a second SSD:

Using the GUI:

1. Replicate the jails back to an existing pool.
2. Remove the smaller SSD.
3. Add the larger SSDs and create a mirror.
4. Replicate the jails back to the mirror.

 

[danb35]

More for my own learning, could the following ways work?

Both of those would serve to get the data onto a mirrored pool of larger SSDs, but neither of them keeps it on the same pool as it was in the beginning. You can even rename the new pool, but either of the two methods you mention is going to take the jails offline for a while. I'm trying to avoid that.

 

[Heracles]

Hey Danb35,

I would add the bigger SSD as a mirror first. That way, the actual SSD is untouched and redundancy is achieved from the first step. Then I would do the auto-expand by replacing the smaller drive with a bigger one. I did many auto-expands and it always worked perfectly.

By replacing the only drive, I see a higher risk to end up in the middle of nowhere should something goes wrong. By creating a mirror first, the first drive is meant to stay part of it and online instead of going offline at some moment.

 

[danb35]

Those are some good points, thanks.

 

[Jailer]

I would add the bigger SSD as a mirror first. That way, the actual SSD is untouched and redundancy is achieved from the first step.

This is kind of what I was thinking as well. Make it safe first then expand.

 

[garm]

Hey Danb35,

I would add the bigger SSD as a mirror first. That way, the actual SSD is untouched and redundancy is achieved from the first step. Then I would do the auto-expand by replacing the smaller drive with a bigger one. I did many auto-expands and it always worked perfectly.

By replacing the only drive, I see a higher risk to end up in the middle of nowhere should something goes wrong. By creating a mirror first, the first drive is meant to stay part of it and online instead of going offline at some moment.

Hear hear

 

[danb35]

Thanks, all--it certainly makes sense, and better safe than sorry.

 

[ccav]

Hey Danb35,

I would add the bigger SSD as a mirror first. That way, the actual SSD is untouched and redundancy is achieved from the first step. Then I would do the auto-expand by replacing the smaller drive with a bigger one. I did many auto-expands and it always worked perfectly.

By replacing the only drive, I see a higher risk to end up in the middle of nowhere should something goes wrong. By creating a mirror first, the first drive is meant to stay part of it and online instead of going offline at some moment.

hello,

2x 16G Verbatim USB keys mirrored for boot

Is the U pan system stable? How long has it been running? Thank you!

 

[Heracles]

Hi,

Yes, my setup is stable. USB sticks are known to be higher risks than SSD for boot, but things are fine here. The system is always on, so not too many access to the sticks because everything is loaded in RAM. Thanks to the mirror, should one fail, FreeNAS will tell me about the degraded boot pool and I should have the time to replace it. In all cases, should I be wrong and both fail at once, I do backup the config with TrueCommand and so a restore will be fast and easy.

At the end, I am happy with that setup.

EDIT: As for how long it has been running, I would say about 18 months on these USB...

 

[ccav]

Ťhank you,i try it now!