Volumes mirror

[mdimuzio]

Hi,
how-to build two volumes which the first volume is the exact mirror of the latter volume ?

My customer want to manage a "disaster-recovery" situation on which a iSCSI volume go down and we switch the FreeNAS volume from the first (totally damaged) to the second (up with a mirror copy of the firest) ... I don't know if I expained well the situation in my poor English level.

HowTo make a FreeNAS volume2 the mirror of a FreeNAS volume1 ? Is this possibile with the rsync tool ? If no, what other tools ?



Tnx,
Marco.

 

[Robert Trevellyan]

Sounds like a job for snapshots and replication.

 

[Bidule0hm]

Replication is the way to go, see the manual for the details ;)

 

[mdimuzio]

Replication is the way to go, see the manual for the details ;)

Tnx Bidule0hm and tnx Robert Trevellyan, but I want to mirror a volume of the self SuperMicro where I installed inside the volumes.

From the chapter 8.3 of the official FreeNAS 9.3.1 User Guide I read
"...A replication task allows you to automate the copy of ZFS snapshots to another system over an encrypted connection.
This allows you to create an off-site backup of a ZFS dataset or pool..."

Good, wonderful, but I want that the replication task automate the replica on our FreeNAS locally volumes. So, I want a off-site backup, but locally.

HowTo ?


Tnx again

 

[Bidule0hm]

It's possible, even replication on the same system but to another pool is possible. Just follow the manual.

 

[Robert Trevellyan]

HowTo ?

You can use localhost as the remote hostname to replicate locally.

 

[SweetAndLow]

Tnx Bidule0hm and tnx Robert Trevellyan, but I want to mirror a volume of the self SuperMicro where I installed inside the volumes.

From the chapter 8.3 of the official FreeNAS 9.3.1 User Guide I read
"...A replication task allows you to automate the copy of ZFS snapshots to another system over an encrypted connection.
This allows you to create an off-site backup of a ZFS dataset or pool..."

Good, wonderful, but I want that the replication task automate the replica on our FreeNAS locally volumes. So, I want a off-site backup, but locally.

HowTo ?


Tnx again

Make the destination localhost?

Do you expect automatic failover type functionality? Because freenas can't do that.

 

[mdimuzio]

SweetAndLow : not automatic failover, but a functionality to have a backup of a failure volume and irrecoverable.


This morning I received by email : "The system was unable to replicate snapshot iscsivolume1 to localhost ====================== No ECDSA host key is known for localhost and you have requested strict checking. Host key verification failed.
"

Where I'm wrong?

 

[SweetAndLow]

Did you setup ssh keys and do they work? ssh localhost with root should just work without password.

 

[mdimuzio]

In my FreeNAS

1) /root/.ssh/authorized_keys = /data/ssh/replication.pub

but

2) /etc/ssh/ssh_host_rsa_key.pub != (/root/.ssh/authorized_keys and /data/ssh/replication.pub)


Does the condition number 2) it's correct?

Tnx

 

[SweetAndLow]

View attachment 8659


In my FreeNAS

1) /root/.ssh/authorized_keys = /data/ssh/replication.pub

but

2) /etc/ssh/ssh_host_rsa_key.pub != (/root/.ssh/authorized_keys and /data/ssh/replication.pub)


Does the condition number 2) it's correct?

Tnx

I have no clue how to set it up. Did you follow the steps in the manual? I think all you have to do is generate a key pair then put the public key in the ssh box for the user you want in the GUI.

 

[toadman]

http://doc.freenas.org/9.3/freenas_storage.html#replication-tasks

PUSH and PULL are the same system in this case. Since it's the same system and no external network involved I would think the OP would just disable encryption (via the encryption cipher box in the replication task settings). But if not:

"Go to PULL and click Account ‣ Users ‣ View Users. Click the “Modify User” button for the user account you will be using for replication (by default this is the root user). Paste the copied key into the “SSH Public Key” field and click “OK”. If a key already exists, append the new text after the existing key.

On PULL, ensure that the SSH service is enabled in Services ‣ Control Services. Start it if it is not already running.

...

On PUSH, verify that a periodic snapshot task has been created and that at least one snapshot is listed in Storage ‣ Snapshots.

To create the replication task, click Storage ‣ Replication Tasks ‣ Add Replication which will open the screen shown in Figure 8.3b. For this example, the required configuration is as follows:

• the Volume/Dataset is local/data
• the Remote ZFS Volume/Dataset is remote
• the Remote hostname is 192.168.2.6
• the Begin and End times are at their default values, meaning that replication will occur whenever a snapshot is created
• once the Remote hostname is input, click the “SSH Key Scan” button; assuming the address is reachable and the SSH service is running on PULL, its key will automatically be populated to the “Remote hostkey” box"

 

[Robert Trevellyan]

I would think the OP would just disable encryption

What difference would that make, other than perhaps affecting performance?

 

[toadman]

Maybe nothing. When I saw "No ECDSA host key is known for localhost " I jumped to the conclusion (perhaps prematurely) the issue was with the replication stream encryption vs. opening the ssh session. Hence the suggestion to turn off encryption of the replication stream. I've been playing with replication since it failed to setup for me on 9.3.1 and the ECDSA is what is used for "Fast" encryption. (I think.)

 

[Robert Trevellyan]

When I saw "No ECDSA host key is known for localhost "

I'm pretty sure that relates to key-based SSH authentication, which is required for automatic replication on FreeNAS. Encryption, if enabled, would use one-time keys. Disabling encryption certainly makes sense for local replication, but I don't think it's the issue.