Mirroring Win2k shares over a WAN

[linmatt]

I want to be able to mirror some of the shares on 3 servers to shares on a NAS box over a WAN. It'll be about 10GB but has to run over night on a Saturday as that's the only time the network is quiet enough.

Is there any software that I can use to do it? I've looked at things like xcopy, but only want to do incremental copies - only files that have changed. Googling has produced nothing usefull. I'm happy to use VBS but have very limited knowledge and even less experience with it.

Thanks

Matt

 

[GenesisCraigM]

You could use XCOPY. I don't though because of the amount of data we're mirroring.

In our company, we presently have 5 active directory sites, one of which is our headquarters and NOC. We only have 256k connections via WAN from the NOC to those locations. Because offsite backup and share mirroring would have been VERY slow over this connection using File Replication Service, we decided to use RSYNC. Also, the fact that FRS keeps breaking and fixing itself between Windows hotfixes was another reason.

If you're familiar with UNIX, you shouldn't have any problem setting up rsync. (You would need to install Cygwin -- just do a google for cygwin). Please be aware that you should be very comfortable using a unix system and the commandline if you decide to use this. And get ready to spend a lot of time debugging the config, etc.

The way rsync works is that it copies binary changes of the files that have changed. Not only does it only ship the files that have changed, but it also only ships the PARTS of the file that have changed .. strictly binary level changes.

We can mirror all 4 branch offices (about 30GB of data each) to our HQ office over 256k connections in just an hour or so, depending on how much has changed that day.

--

Cygwin is a POSIX / UNIX subsystem for Windows. It includes many tools such as rsync, wget, squid proxy, etc.

If you do use rsync though, don't ever use any of it's settings to maintain permissions and ownerships .. they will break your security. That's not a problem though because your destination shares should have permissions set up properly and to act recursively on any files copied to it.



Craig J Matthews
System Administrator, Genesis Group
craigm@genesisgroup.com

 

[jeremymc]

Xcopy will work for incremental file change. Just do a xcopy \\remoteserver\remoteshare *.* /E /D /Y /C
from the directory you want to copy too. The above command is /E for everything including subdirectories if you need them. /D is for only newer files (your incremental) /Y is to overright without prompting, and /C is to continue incase there is some error (like a corrupt file). We use this extensivly and /C really helps when using it as a schedule task to make sure it doesn't have errors. You can even pipe the results out to a text file by putting the above in a batch file, then having another batch file call that batch file with a pipe commed to a results.txt. that way if you schedule it you have the results logged.

 

[wanabdba]

I'm very happy with this replication software.

http://spursuits.com/SureSync/SureSync.htm

I hope this helps.

 

[xmsre]

Doubletake is another replication solution. Out of the box there's the FRS, with sometimes questionable stability, or XCOPY/ROBOCOPY on a schedule with all it's associated drawbacks.

On level up and you can use a 3rd party replication utility like doubletake, or RSync, or SureSync as mentiond in this thread. These offer better control of the content that's replicated, reduction of replication overhead, and the choice of synchronous or asynchronous replication.

Going further, you could seek a hardware distance mirroring solution from vendors like Dell, EMC, HP, Hitachi, Xiotech, and a cast of many more. These systems require a typically larger outlay, but have the benefit that the whole process is invisible to the server.

No matter which route you go, it's going to have a negative impact on the performance of your file server. IO is IO, whether the OS sees it or not, and additional load on the storage subsytem due to replication may impact the normal operation and responsiveness of your server. Take this into account when you size your storage, and add enough drives to handle the extra load.