Nas to Nas Mirror

[ICTNUT]

Hi Guys,

Looking for ideas on how to best achieve a NAS to NAS mirror or replication.

I have 2 1TB NAS boxes (full blown Windows 2003 Storage servers) and would like to:

a) replicate the boxes
b) provide failover

What do you guys think would be the best way to do this??

The replication could be the hardest part as this will need to be near continuous so as to provide as near to idetical files soif one server drops of the mapthe other is already there.

Then the is the clustering (possibly), round robin (possibly), DFS (likely) to ensure that users have seamless access to files.

I am looking to replicate ALL users home shares and a couple of other shares also.

[mattx]

Not sure what NAS boxes you are using - [ I personally use FREEnas ] - I have two 1 TB boxes both replicating using the inbuilt Rsync.
Google Rsync and you will find plenty of options for both Linux & Windows boxes......

Just did a quick google myself and found this:

http://www.brentnorris.net/rsyncntdoc.html

[ICTNUT]

thanks mattx I will look into it, I did not even think about using rsync on windows, but there ya go !

[Geoff]

Rsync will work fine. If you want a windows alternative (even though rsync is ported) try robocopy.

[Osprey]

You mentioned DFS. Anyone else using it successfully for user areas?

[Geoff]

User areas change too frequently in my experience. Leading to DFS getting confused.

[ICTNUT]

I agree with Geoff, we already have it in place for things that change maybe a couple of time a week but when you have changes taking place every few seconds you're going to get issues.

[Ben_Stanton]

http://www.experts-exchange.com/Stor..._22616161.html

[plexer]

Would be interested to hear what you go for in the end.

I am thinking of putting an Openfiler box into the server room for the servers to back up to at night and then during the day mirror this over to the buffalo in the remote location.

At the moment I think it takes too long for all the servers to backup direct to the buffalo so this may speed things up.

Ben

[ICTNUT]

I am still looking into it and have not yet decided on what to go for, I may look at M$ Data Protection Manager as this will do realtime sync's by using one of the onbaord NICs as a lifeline similar to how clusters work.

I'll let you know what solution I go for once I have sussed it out.

[FN-GM]

Just out of curiosity what did you end up doing please?

[dhicks]

Looking for ideas on how to best achieve a NAS to NAS mirror or replication.

I'd run your Windows 2003 servers as Xen virtual machines replicated between machines with DRBD running on CentOS. Easy to set up, no cost (best if you have a separate network interface to directly connect the two machines, but that's not expensive these days), replicates in real-time, capable of fail-over with an estimated downtime of something like 300ms (according to the documentation...).

--
David Hicks

[ICTNUT]

Have not gone for a realtime nas to nas mirror as this would take time to setup and this is something I just don't have at the moment.

I have the following in place as part of the backup scheme:

NAS1 is primary (active) and holds all staff and student files
NAS2 is secondary (passive) and holds sync'd data

A robocopy script runs twice a day (08:00 & 13:00) on NAS1 running a sync over to NAS2 with full permissions copied over as well using a dedicated server to server link, 1Gb NICs

This will ensure that if NAS1 dies then it just a case of repointing to NAS2, yes depending on when NAS1 dies does mean that there maybe some files missing but at least uptime is maintained and the school could continue.

The same robocopy script then runs at 23:00 each day doing a full copy without permissions to a linux NAS box which than backsup to a tape drive for backup purposes, this removes a restricted backup window.

Used alongside VSS on NAS1 this means that files can be recovered directly on NAS1 if it is still up and running without having to access NAS2 unless I really have too .

[SOSAGES]

id also consider:

taking another synched nas home with you.
using amazon s3 (or something like it) to upload all the files to, nothing like having an online backup id check out jungletools and then run a robocopy job

[gshaw]

If you've got spare cash then DoubleTake will do what you want and can also provide failover i.e. NAS02 takes the full identity of NAS01.

Gotta be careful with it though as it can sense a failure when there isn't one e.g. Windows Update reboot then u end up with IP conflicts. Ours is set to manual failover and continuous replication over a fiber link (quick!)