Hyper-V Replica

[fiza]

There has been some talk on here about HyperV Replica available in 2012 but is anyone using it?

I have 2 servers (not identical) both with 32Gb RAM and with the spec to run as HyperV hosts. I want to set one up as a HyperV host and then use HyperV Replica to replicate the VMs to the other Server so that if the first was to go down for any reason then we could fire up our VMs on the second server. We dont have a SAN and all the VMs would be local.

 

Is anyone using it like this?

[glennda]

Not sure if it is nativly possible within Hyper-V but it does sound like that Veeam is for.

[fiza]

I was reading failover - Adding redundancy to Hyper-V without a SAN - Server Fault

 

and the point that grabbed me was :

 

"It will allow you to run virtual machines on each of your hosts and it will replicate the contents of the virtual hard disk to the other host, asynchronously. If a host crashes, you can restart the VM on the other host, having lost some amount of data that hadn't yet been replicated."

 

That is exactly what I want to do. So wondered if anyone already using 2012 was doing this?

[tmcd35]

I am literally installing 2012 on my second virtual host as I type (it's doing Windows Updates ). I'm upgrading our host servers and storage server to 2012 for this very reason (and SMB v3 is supposed to faster than v2). Once this server is online failover clustering is the next thing I'm looking at. All our VM config files and VHD are stored in a SMB share on the storage server. It was that way under 2008R2 (not officially supported), but 2008R2 didn't support migration without a SAN.

 

One thing I'm debating is whether to leave the set up as is, with VHD's in a SMB share, or shrink the storage volume on the storage server to make space for an iSCSI volume or two for the VHD's since 2012 (finally) supports iSCSI hosting!

Edited February 6, 2013 by tmcd35

[fiza]

Just watched an interesting video on Hyper-V Replica

 

Windows Server 2012 Virtualization - Hyper-V Replica - Welcome to the US SMB&D TS2 Team Blog - Site Home - TechNet Blogs

[lmgtfy]

There has been some talk on here about HyperV Replica available in 2012 but is anyone using it?

I have 2 servers (not identical) both with 32Gb RAM and with the spec to run as HyperV hosts. I want to set one up as a HyperV host and then use HyperV Replica to replicate the VMs to the other Server so that if the first was to go down for any reason then we could fire up our VMs on the second server. We dont have a SAN and all the VMs would be local.

 

Is anyone using it like this?

 

Yes I can confirm we have this setup and it works nicely. It will sync every 5 mins all the changes (I don't think you can change this) so as long as there are not huge files changes I.E a media server it should only be small file transfers between the two servers. If you need to fail over you just logon to the replicate server and choose fail over and it will then startup as normal. You can then fail back when the other server is backup and it will copy all the files back to original server so there is no need for big down time. For a built in free feature it is very good.

[Chuckster]

So, let me get this right, you can have all this without having a SAN?

 

If so, this hugely sways me in favour of ditching VMware for Hyper-V 2012, as you can get Hyper-V 2012 for free as a complete standalone installation than purchasing the Standard or Enterprise Edition.

[lmgtfy]

Yes, I think a lot of people have realised they could say a lot of money with this moving away from VMware for this feature alone. Look at this blog Windows Server 2012 Hyper-V Replica … In Detail he does lots of blogs on Hyper-v.

[glennda]

Yes, I think a lot of people have realised they could say a lot of money with this moving away from VMware for this feature alone. Look at this blog Windows Server 2012 Hyper-V Replica … In Detail he does lots of blogs on Hyper-v.

 

Only in education, private vmware is still king as hyper-v still isn't all that cheap.

[glennda]

So, let me get this right, you can have all this without having a SAN?

 

If so, this hugely sways me in favour of ditching VMware for Hyper-V 2012, as you can get Hyper-V 2012 for free as a complete standalone installation than purchasing the Standard or Enterprise Edition.

 

Also take a look at VMware Storeage VMotion - slightly different ways around doing it but the same. Live migration without a SAN.

 

Hyper-V is still a much inferior product than VMware, but if you don't require the extra features that VMware has then Hyper-V is a very good alternative product.

[tmcd35]

Looks like I was getting Hyper-V Replica confused with the arguably more useful Hyper-V over SMB 3:

 

Deploy Hyper-V over SMB

 

Depending on your environment this could well be a better solution than replicating snapshots between servers every 5 minutes. The VM's are always live and up to date, as they would be in a SAN environment, and you don't need the hard drives space on all hosts in the cluster to store the replicated data - just one centrallised location that all hosts can see and access.

[fiza]

Yes I can confirm we have this setup and it works nicely. It will sync every 5 mins all the changes (I don't think you can change this) so as long as there are not huge files changes I.E a media server it should only be small file transfers between the two servers. If you need to fail over you just logon to the replicate server and choose fail over and it will then startup as normal. You can then fail back when the other server is backup and it will copy all the files back to original server so there is no need for big down time. For a built in free feature it is very good.

 

What VMs do you have replicating?

[lmgtfy]

I have it replicating everything but the media server and the backup servers and it works well.

 

Only in education, private vmware is still king as hyper-v still isn't all that cheap.

To be fair this is edugeek Arguably though lots of people are saying that Hyper-V has now overtaken VMware but I don't want to start a Apple vs Android type discussion

[fiza]

I have it replicating everything but the media server and the backup servers and it works well.

 

Including SIMS?

[lmgtfy]

To be fair thats one of the last physical servers we have left to virtualise and yes maybe heavy SQL servers wouldn't be a good idea to replicate. All I can say is give it some testing we will be either half term or at Easter. Hyper-V manager provides some very good stats on network activity, file size etc for the replica so if you find its hogging resources you could always turn it off on that server.

[glennda]

I have it replicating everything but the media server and the backup servers and it works well.

 

To be fair this is edugeek Arguably though lots of people are saying that Hyper-V has now overtaken VMware but I don't want to start a Apple vs Android type discussion

 

That is true, but there is lots of people here who work in industry. If I am honest i would rather use open source virtulisation than Hyper-v something like cloud stack etc

[midweek]

Looks like I was getting Hyper-V Replica confused with the arguably more useful Hyper-V over SMB 3:

 

Deploy Hyper-V over SMB

 

Depending on your environment this could well be a better solution than replicating snapshots between servers every 5 minutes. The VM's are always live and up to date, as they would be in a SAN environment, and you don't need the hard drives space on all hosts in the cluster to store the replicated data - just one centrallised location that all hosts can see and access.

 

Just set this up on a properly cobbled together test environment (Dell SC440, Dell Optiplex 745 and and old Gigabyte motherboard with various bits plugged in!). Had two hypervisors in a cluster using the third "server" as shared storage using Server 2012 Storage Spaces and SMB shares.

Seems to work pretty well. I can live migrate the VMs across no trouble and physically pulling the plug on one hypervisor causes the VMs to migrate automatically.

 

So technically I've got high availability without a SAN! Can't really comment on the speed of it all (although it does only take seconds to perform a migration) or how well it would scale up into a production environment with proper DR and all the rest but it's an interesting start.