Maybe a better question is: What is the closest competitor for DoubleTake? I am looking to replicate a windows production server in case it fails have a immediate backup. Any idead?
NOTE 1: I forget to add that this server is on the EC2 Amazon Cloud.
NOTE 2: The main situation we have is recreating the configuration settings like IIS, FTP Server, SQL Server, SVN Server.
NOTE 3:
So far I have been giving three options as answers for my original question:
- AppAssurance -- After talking to their sales team they do not support Amazon as cloud provider. Basically there is a technical need to be able to reboot from a disk or similar media. So ESX Virtual machine environment will work, but not the EC2.
- Acronis -- which works as a backup in ghost style. This will work for other type of scenarios.
- Use the Amazon EC2 API -- This option is ideal, but only works if you are developing a cloud application rather than hosting a regular application in a cloud scenario.
This means that I am still looking for the answer. Any other ideas.
I have used Acronis' products a lot and they can do what you want (take disk-based image of the whole disks or individual partitions). Product used to be called True Image Echo, but newest version 10 is now named Acronis Backup & Recovery.
One trick you could use to retain your all your FTP or IIS configuration state is to unset the "Ec2InitializeDrives" option in the Windows configuration service.
Once you completed configuring your server, unset the above option and then bundle your instance. The next time you launch an instance from the AMI that you just created, it should retain all your configuration state.
For IIS, you should ideally have your IIS application on an EBS source volume. Everytime you need to launch a new IIS instance, you'd start up a new instance, create and attach a new EBS volume to the instance and then copy the inetpub files from the EBS source volume. Run whatever scripts you need to config your apps and the start the website.
It'd be a similar approach for SQL. Once you've bundled the SQL Server w/o initialzing drives you would maintain configuration states. You should store all your SQL Server data on an EBS volume. You can use the Ec2Config service to attach the EBS volume to your instance on the same drive letter the SQL server is expecting to find the data files. Set your SQL server startup type to manual. Have a startup script that verifies the EBS volumes have been attached. Once the EBS volumes are attached, start the SQL server. When you then spin up a new SQL instance based your fully scripted AMI it should startup with SQL running.
This works for me on SQL and IIS on Windows 2003.
it's in the cloud and the cloud can't fail right? My understanding is that they provide you with a c# library to do management do the cloud but it's not a VPS, it just a bunch of windows services dedicated to you. You have to create an AMI image. See Amazon EC2 AMI Tools for the utility to create an AMI image. Docs for the utility are here
We are currently using a product called Replay from AppAssure, I can honestly say I have been extremely happy. While we are not using it to replicate cloud based machines we are using it to replicate to physical machines from one site to another. The software uses block level copy and can be set to snapshot as quickly as every 5 minutes or as slow as several hours. Because it uses an agent you should be able to run the agent in the cloud on another machine and keep the production and the DR both their and ready to go I would imagine.
I'm not sure how the amazon cloud stuff works. But my solution to this problem is to setup an IIS cluster, or preferably a VM cluster(R2 for live migration, but bleeding edge). Shared Storage would be required and I'm not sure how that fits into the amazon cloud config.
Leaving the cloud stuff aside, and getting back to DoubleTake, here's what my own research some time ago showed:
There were three major products that would provide server replication on the same level - DoubleTake, XOSoft WanSync-HA and NeverFail.
I have tried all three and ended up buying NeverFail, because the others were simply too expensive, while the feature set was pretty much the same.
The product didn't prove to be very good actually, when used over WAN, replicating MSTS, Exchange2003 and a few other servers between Russia and Israel. The split brain mechanism gave me some headache, because the servers tended to fail over as soon as the link would become slow. I'm sure that in a LAN environment things would have been better though. The licensing scheme that had to be renewed every year for a few thousand dollars didn't make me too happy either btw.
But when the main server died, it was NF that saved the day after all.
We use a product called Replistor. Works fine on the LAN but never seems to catch up across the WAN. I have been following AppAssure because I believe it does backup, replications and more but I keep getting told that Replistor is a more robust product. Not sure how they stackup against each other.