This post is part of a short series on migrating my home hypervisor off of iSCSI.
- Home Lab – No More iSCSI: Prep and Planning
- Home Lab – No More iSCSI: Transfer, Shutdown, and Rebuild (this post)
- Home Lab – No More iSCSI: Backup plans (coming soon)
Observations – Migrating Servers
The focus of my hobby time over the few days has been moving production assets to the temporary server. Most of it is fairly vanilla, but I have a few observations worth noting.
- I forgot how easy it was to replicate and failover VMs with Hyper-V. Sure, I could have tried a live migration, but creating a replica, shutting down the machine, and failing over was painless.
- Do not forget to provision an external virtual switch on your Hyper-V servers. Yes, sounds stupid, but, I dove right in to setting the temporary server up as a replication server, and upon trying to failover, realized that the machine on the new server did not have a network connection.
- I moved my Minio instance to the Synology: I originally had my Minio server running on an Ubuntu VM on my hypervisor, but decided moving the storage application closer to the storage medium was generally a good idea.
- For my Kubernetes nodes, it was easier to provision new nodes on the temp server than it was to do a live migration or planned failover. I followed my normal process for provisioning new nodes and decommissioning old ones, and viola, my production cluster is on the temporary server. I will simply reverse the process for the transfer back.
- I am getting noticeably better performance on the temporary server, which has far less compute and RAM, but the VMs are on local disks. While the Synology has been a rock solid, I think I have been throwing too much at it, and it can slow down from time to time.
Let me be clear: My network storage is by no means bad, and it will be utilized. But storing the primary vhdx files for my VMs on the hypervisor provides much better performance.
Shut It Down!
After successfully moving my production assets over to the temporary server, it was time to shut it down. I shut down the VMs that remained on the original hypervisor and attempted to copy the VMs to a network drive on the Synology. That was a giant mistake.
Those VM files already live on the Synology as part of an iSCSI volume. By trying to pull those files off of the iSCSI drive and copy them back to the Synology, I was basically doing a huge file copy (like, 600+ GB huge) without the systems really knowing it was copy. As you can imagine, the performance was terrible.
I found a 600TB SAS drive that I was able to plug into the old hypervisor, and I used that as a temporary location for the copy. Even with that change, the copy took a while (I think about 3 hours).
Upgrade and Install
I mounted my new SSDs (Samsung EVO 1TB) in some drive trays and plugged them into the server. A quick boot to the Smart Storage administrator let me setup a new drive array. While I thought about just using RAID 0 and letting me have 2 TB of stuff, I went the safe option and used RAID 1.
Having configured the temporary server with Windows Server Hyper-V 2019, the process of doing it again was, well, pretty standard. I booted to the USB stick I created earlier for Hyper-V 2019 and went through the paces. My domain controller was still live (thanks temporary server!), so I was able to add the machine to domain and then perform all of the management via the Server Manager tool on my laptop.
Moving back in
I have the server back up with a nice new 1TB drive for my VMs. That’s a far cry from the 4 TB of storage I had allocated on the SAN target on the Synology, so I have to be more careful with my storage.
Now, if I set a Hyper-V disk to, say, 100Gb, Hyper-V does not actually provision a file that is 100Gb: the
vhdx file grows with time. But that does not mean I should just mindlessly provision disk space on my VMs.
For my Kubernetes nodes, looking at my usage, 50GB is more than enough for those disks. All persistent storage for those workloads is handled by an NFS provisioner which configures shares on the Synology. As for the domain controllers, I am able to run with minimal storage because, well, it is a tiny domain.
The problem children are Minio and my SQL Server Databases. Minio I covered above, moving it to the Synology directly. SQL Server, however, is a different animal.
Why be you, when you can be new!
I already had my production SQL instance running on another server. Rather than move it around and then mess with storage, I felt the safer solution was to provision a new SQL Server instance and migrate my databases. I only have 4 databases on that server, so moving databases is not a monumental task.
A new server affords me two things:
- Latest and greatest version of Windows and SQL server.
- Minimal storage on the hypervisor disk itself. I provisioned only about 80 GB for the main virtual disk. This worked fine, except that I ran into a storage compatibility issue that needed a small workaround.
SMB 3.0, but only certain ones
My original intent was to create a virtual disk on a network share on the Synology, and mount that disk to the new SQL Server VM. That way, to the SQL Server, the storage is local, but the SQL data would be on the Synology.
Hyper-V did not like this. I was able to create a
vhdx file on a share just fine, but when I tried to add it to a VM using
Add-VMHardDiskDrive, I got the following error:
Remote SMB share does not support resiliency.
A quick Google search turned up this Spiceworks question, where the only answer suggests that the Synology SMB 3.0 implementation is Linux-based, where Hyper-V is looking to use the Windows-based implementation, and that there are things missing in Linux.
While I am usually not one to take one answer and call it fact, I also didn’t want to spend too much time getting into the nitty gritty. I knew it was a possibility that this wasn’t going to work, and, in the interest of time, I went back to my old pal iSCSI. I provisioned a small iSCSI LUN (300 GB) and mounted directly in the virtual machine. So now my SQL Server has a data drive that uses the Synology for storage.
And we’re back!
Moves like this provide an opportunity for consolidation, updates, and improvements, and I seized some of those opportunities:
- I provisioned new Active Directory Domain controllers on updated operating systems, switched over, and deleted the old one.
- I moved Minio to my Synology, and moved Hashicorp Vault to my Kubernetes cluster (using Minio as a storage backend). This removed 2 virtual machines from the hypervisor.
- I provisioned a new SQL Server and migrated my production databases to it.
- Compared to the rats nest of network configuration I had, the networking on the hypervisor is much simpler:
- 1 standard NIC with a static IP so that I can get in and out of the hypervisor itself.
- 1 teamed NIC with a static IP attached to the Hyper-V Virtual Switch.
- For the moment, I did not bring back my “non-production” cluster. It was only running test/stage environments of some of my home projects. For the time being, I will most likely move these workloads to my internal cluster.
I was able to shut down the temporary server, meaning, at least in my mind, I am back to where I was. However, now that I have things on the hypervisor itself, my next step is to ensure I am appropriately backing things up. I will finish this series with a post on my backup configuration.