Replication - between pools in the same system
By Steve Tunstall on Oct 26, 2012
OK, I fully understand that's it's been a LONG time since I've blogged with any tips or tricks on the ZFSSA, and I'm way behind. Hey, I just wrote TWO BLOGS ON THE SAME DAY!!! Make sure you keep scrolling down to see the next one too, or you may have missed it. To celebrate, for the one or two of you out there who are still reading this, I got something for you. The first TWO people who make any comment below, with your real name and email so I can contact you, will get some cool Oracle SWAG that I have to give away. Don't get excited, it's not an iPad, but it pretty good stuff. Only the first two, so if you already see two below, then settle down.
Now, let's talk about Replication and Migration. I have talked before about Shadow Migration here: https://blogs.oracle.com/7000tips/entry/shadow_migration
Shadow Migration lets one take a NFS or CIFS share in one pool on a system and migrate that data over to another pool in the same system. That's handy, but right now it's only for file systems like NFS and CIFS. It will not work for LUNs. LUN shadow migration is a roadmap item, however.
So.... What if you have a ZFSSA cluster with multiple pools, and you have a LUN in one pool but later you decide it's best if it was in the other pool? No problem. Replication to the rescue. What's that? Replication is only for replicating data between two different systems? Who told you that? We've been able to replicate to the same system now for a few code updates back. These instructions below will also work just fine if you're setting up replication between two different systems. After replication is complete, you can easily break replication, change the new LUN into a primary LUN and then delete the source LUN. Bam.
Step 1- setup a target system. In our case, the target system is ourself, but you still have to set it up like it's far away. Go to Configuration-->Services-->Remote Replication. Click the plus sign and setup the target, which is the ZFSSA you're on now.
Step 2. Now you can go to the LUN you want to replicate. Take note which Pool and Project you're in. In my case, I have a LUN in Pool2 called LUNp2 that I wish to replicate to Pool1.
Step 3. In my case, I made a Project called "Luns" and it has LUNp2 inside of it. I am going to replicate the Project, which will automatically replicate all of the LUNs and/or Filesystems inside of it. Now, you can also replicate from the Share level instead of the Project. That will only replicate the share, and not all the other shares of a project. If someone tells you that if you replicate a share, it always replicates all the other shares also in that Project, don't listen to them.
Note below how I can choose not only the Target (which is myself), but I can also choose which Pool to replicate it to. So I choose Pool1.
Step 4. I did not choose a schedule or pick the "Continuous" button, which means my replication will be manual only. I can now push the Manual Replicate button on my Actions list and you will see it start. You will see both a barber pole animation and also an update in the status bar on the top of the screen that a replication event has begun. This also goes into the event log.
Step 5. The status bar will also log an event when it's done.
Step 6. If you go back to Configuration-->Services-->Remote Replication, you will see your event.
Step 7. Done. To see your new replica, go to the other Pool (Pool1 for me), and click the "Replica" area below the words "Filesystems | LUNs" Here, you will see any replicas that have come in from any of your sources. It's a simple matter from here to break the replication, which will change this to a "Local" LUN, and then delete the original LUN back in Pool2.
Ok, that's all for now, but I promise to give out more tricks sometime in November !!! There's very exciting stuff coming down the pipe for the ZFSSA. Both new hardware and new software features that I'm just drooling over. That's all I can say, but contact your local sales SC to get a NDA roadmap talk if you want to hear more.