Adding a Drive to turn an existing Stripe into a Mirror

[josecuervo]

Running FreeNAS-9.3-STABLE fully updated.

I have one 3TB drive and I want to add another to create a mirror. I plan to follow this post:

OMG! What a nerve wrecking ride. IT WORKED! No complaints from FreeNas GUI. Thanks so much fellas!

Here's the steps along with my setup for future reference

• FreeNas version 9.2.1.5 booted from 16gb USB stick
• One volume consisting of 2x2tb mirror and a single stripe 1x1tb drive

Steps to convert a single stripe to mirror

1. From GUI, detach the volume, shutdown and unplug the existing drives. Install a fresh 1x1tb drive.
2. Startup again and you should only see one disk under View Disks. Run the command with Shell and clear any existing partitions on the new drive
   
   
   Code:

   gpart destroy -F /dev/ada0

   
   
   
3. Create the new partitions
   
   
   Code:

   gpart create -s gpt /dev/ada0
   gpart add -a 4k -i 1 -s 2g -t freebsd-swap /dev/ada0
   gpart add -a 4k -i 2 -t freebsd-zfs /dev/ada0

• Check out the new gptid for the drive and copy down the gptid for ada0p2
  
  
  Code:

  glabel status

• Shut down. Replug all the drives. Restart. Go to Storage and Auto-Import the volume

• Go to Volume Status and take note of the name for the stripe eg ada1p2

• Check out the gptid again and this time find the gptid for ada1p2
  
  
  Code:

  glabel status

• Finally, run the command to set the stripe as a mirror where tank is the name of the volume. IMPORTANT: gptid for the existing disk comes first
  
  
  Code:

  zpool attach tank /dev/gptid/[gptid_of_the_existing_disk] /dev/gptid/[gptid_of_the_new_partition]

• Go back to the GUI Volume Status and you'll see a new mirror. You can check the reslivering process with the following command
  
  
  Code:

  zpool status

Any comments before I start?

Thanks,
Jose

 

[Apollo]

Never tried so I can't comment on it, but as a side question do you have any backup plans?
If you have another drive, same size or bigger, then you can use replication. One way would be to create your mirror first, then do replication from your existing drive to the mirror. After replication is done, you will need to link the various shares and accounts to the new mirror and take the drive with the existing data out of the system as backup.
Or you can replicate to a larger drive, then disconnect old drive and create a new mirror from it and the new drive. You can then import the old backup through replication, the same way you went.
The replication approaches, while a bit daunting is in my opinion a bit safer approach to your problem. You can fail (and you should still have your data, unless for user entry error) and try until you succeed, while yours could potentially cost you your data.

 

[mjws00]

It's pretty tough to screw up your data with those directions. Your data is physically disconnected while you are building the second part of the mirror. Nothing is perfect, but those are literally the commands the GUI runs when building a mirror... so it is the best we can do. Obviously a tested backup would be smart. Go slow, but don't sweat it too much.

Good luck.

 

[josecuervo]

It's pretty tough to screw up your data with those directions. Your data is physically disconnected while you are building the second part of the mirror. Nothing is perfect, but those are literally the commands the GUI runs when building a mirror... so it is the best we can do. Obviously a tested backup would be smart. Go slow, but don't sweat it too much.

Good luck.

Is there a GUI way to do what I'm trying to do? Or are you referring to an initial setup

 

[mjws00]

No way to do this in the GUI. But they do have the mechanism for a boot pool so perhaps it will come one day.

 

[josecuervo]

So far so good. On to the zpool attach command. Here is my glabel status:

Ok I know my original disk is ada0p2 from the Volume list but how do I know which which of these gptids is correct for my new disk? Sorry total noob. My guess is ada1p2.

 

[mjws00]

Correct

 

[danb35]

adaXp1 (or daXp1) is the swap partition, adaXp2 or daXp2 is the ZFS data partition.

 

[josecuervo]

Success!

Awesome, thanks so much guys :D !

 

[bleep-io]

Woohoo! Worked perfectly!

Thanks for covering this.

 

[Sean Coston]

I just converted a 3 disk bastardized stripe into a two disk mirrored volume using these instructions. My server only allows for 4 SATA disks, so I had to mount 1x4TB and then copy my data over to it from the 3 disk stripe (1x2TB + 2x500GB) then decommission the smaller disks to make room for the 2nd 4TB disk and construct my mirror.

Worked perfectly.

Thank you so much for figuring this out and posting.

Next I'm installing two more 4TB disks in a mirror then adding the mirror to the volume. That's what I want right? a stripe of mirrors and not a mirror of stripes.

 

[mjws00]

Yep. No way to mirror stripes in zfs. You will have one mirrored vdev and add another.

Glad it worked for ya.

 

[Bjonness406]

Need some help, I am at the last step, but I get this error message.

 

[m0nkey_]

Guys, this is just an FYI. You're doing CLI stuff behind the GUI. There is no way for the middle-ware to know what the heck you did and how to handle it in case of a fault. The correct way to do this is back-up the data, rebuild the vdev as a mirror using the GUI.

 

[Bjonness406]

So I should just copy all my data to a external usb harddrive and make the mirror, then copy it back again?
Can I do that if I plug the harddrive into my freenas machine, or do I need to do it with a client?

 

[m0nkey_]

In a perfect world, yes. Backup your data any way you choose, then destroy and rebuild the pool correctly. Personally, I'd plug the external drive into a client machine and backup over the wire.

 

[Bjonness406]

In a perfect world, yes. Backup your data any way you choose, then destroy and rebuild the pool correctly. Personally, I'd plug the external drive into a client machine and backup over the wire.

Thanks for your help, doing it now :D

Taking a day to copy everything over -_- :p
Edit: Down to 4 hours, not that bad

 

[Bjonness406]

Wait...

Should I backup my data with just copying the folders and set up everything again,
or can I go to System > Advanced > Backup > Backup data?

Or is there any better way to backup without having to set up permissions again, or dataset?

 

[Bjonness406]

Bump

 

[Bjonness406]

Can someone help me? Want to get my server back up running again.