Offsite Replication Support For HyperV Or ESXi

[Chiper]

Gday Everyone,
We are looking for a cost effective offsite replication strategy for our business.

We have 2 sites and would like to replicate the virtual machines (both esxi and hyper v) from our primary office to our secondary office across the WAN.

Is anyone currently doing this using 2 Synology devices and the backup replication which I believe uses RSYNC?

How have you found it?
Is it reliable?

Reading the forums it seems that speed can be an issue as RSYNC is CPU intensive and the CPU's are not very fast on the Synology devices? I dont think this will cause an issue for us as we will be limited by our ADSL2 connection speeds at each site.

Does rsync work with vmdk (ESX) or vhd (HyperV) files?

I.E. lets say you have a 100GB virtual machine and use something like Veeam to copy the (vmdk or vhd file) to the Synology device and then use the Synology backup to another Synology for replication across the wan is it smart enough to only transmit the block level changes instead of the entire 100GB file?

Any advice from users that have experience with setting this up in the past would be greatly appreciated.



Kind Regards,
Chiper

[doanjn]

I'm very interested in this as well. Anyone know if it's possible?

[sup3rior]

First off, you won't be able to use the backup feature in DSM with Hyper-V if you are using the NAS as the primary storage device for the VM's.
This is due to the fact that Windows (up until 2008 R2 that is) requires block-level access to the drive where the VM's are running off and this can only be done by mounting the drives from the NAS as iSCSI devices.
Thereby you effectively eliminate the option to use rsync as a backup method...
If you on the other hand have the VM's running on other storage and simply copy them to the NAS, things are more comparable to ESX as described below...

ESX on the other hand is capable of accessing the drives on the NAS as NFS volumes, whereby they access the drives as file-level access. This in turn grants the ability to use rsync and thereby sync the data to another rsync compatible device.
That was the good news... The bad news is that rsync does not do a block-by-block comparison of the files to be replicated. If a file is marked for backup, that entire file will be moved off to the backup destination.
So if you have X number of virtual machines each with changes to their VMDK or VHD files rsync will inevitabely copy the entire file in the backup proces.

Only case where this wouldn't be true is if the VM's are not running on the NAS but other storage and you have backup software that uses the NAS as its destination AND this software breaks its backups into smaller files...

Hopes this gives a better picture of what you are trying to accomplish...