How to replace my dedicated Jails SSD?

[hungarianhc]

Hi there,

All of my "real data" is on 5 disk Raidz-2 pool, but I have a dedicated SSD that I run my jails from. It's running a bit low in space... I'd like to replace it with a larger one. Is there an easy way to do this? What's the recommended path for doing this? Thanks!

 

[SmallGuy]

Are your jails on a single disc vdev?

 

[hungarianhc]

Are your jails on a single disc vdev?

Yes

 

[HoneyBadger]

The recommended way is to remove the jails and install them on the new, larger storage.

Alternatively, you can attempt to migrate them by following the instructions in this post:

https://forums.freenas.org/index.php?threads/move-jail-directory.18690/#post-103055

Steps:

1. Turn off all plugins (Plugins->Installed)
2. Stop all jails (Jails->View Jails)
3. Run these commands via CLI:
   zfs snapshot -r main_pool/jails@relocate
   zfs send -R main_pool/jails@relocate | zfs receive -v ssd_pool/jails
   zfs get -rH -o name -s received mountpoint ssd_pool/jails | xargs -I {} sh -c "zfs set mountpoint=/{} {}; zfs mount {};"
4. Change the Jail Root to /mnt/ssd_pool/jails (Jails->Configuration)
5. Start jails/plugins
6. Check that everything works and destroy the original jails dataset (main_pool/jails)

 

[SmallGuy]

As your jails are already on the SSD, you have to adapt commands above.
And you have to do it 2 time. 1 to replicate your jails on your main pool and then to move them back to the new SSD.
Not something trivial.
Alternatively, if you have one SATA port available, you can Mirror your SSD and then replace the old one with a second larger SSD.

 

[Robert Trevellyan]

Is there an easy way to do this?

Just use the documented 'Replacing Drives to Grow a ZFS Pool' procedure.

EDIT: clarification/link

 

[pirateghost]

Just use the documented 'disk replacement to grow a pool' procedure.

which doesn't work very well on a 1 disk vdev. ;)

 

[Robert Trevellyan]

which doesn't work very well on a 1 disk vdev. ;)

What makes you think so?

 

[pirateghost]

What makes you think so?

How do you replace the only disk in a single disk vdev and have it replicate its data?

 

[danb35]

You don't offline the original drive, of course. Click on the pool, go to volume status, click the drive to replace, click the Replace button, select the new drive. ZFS will move the data and offline the old disk. Power down and remove it at your convenience.

 

[pirateghost]

interesting. I was not aware of this capability....

 

[Robert Trevellyan]

I was not aware of this capability....

It's documented as an option if you have a spare drive port, and is beneficial for all types of vdev because redundancy is maintained during the resilver.

 

[pirateghost]

It's documented as an option if you have a spare drive port, and is beneficial for all types of vdev because redundancy is maintained during the resilver.

Even for a single disk vdev? I assumed the docs were talking about a typical vdev which would consist of multiple disks.

 

[Robert Trevellyan]

Even for a single disk vdev?

Yup, just checked it in a VM, works fine.

 

[pirateghost]

Cool!

 

[SmallGuy]

interesting. I was not aware of this capability....

Me too.
Nice trick.