Windows 7 - DPM Replica Creation - Help

Asked By TheFair

17-Mar-10 06:37 AM

Hi, I know there is a Technet article detailing the steps required to
manually create a replica in DPM.  What I want to know is how you actually
restore the data from a backup created with BackupExec?  One of the
requirements is to preserve the timestamps, but wont the folder timestamps
have the creation date when restoring the data via BackupExec?  Also, do I
need to follow the steps in the Technet article to provide access to the
replica location to BackupExec?

How has everybody else created their replica?  I am open to suggestions and
will happily exclude backupExec from the solution if it is easier?

Thanks.

17-Mar-10 07:32 AM

Restoring file/folder timestamps is not necessary when manual
replica is created for DPM. You can restore/copy the files to the manual
replica location in anyway like even you can use a xcopy application to
transfer the files, but the manual replica files/folder location is
important you need to follow the instructions mentioned in DPM manual
replica creation method for this. Once manual replication is done, DPM runs
a Consistency check in which it brings the files in the same state as they
are in the protected server by doing a checksum based verification at block
level for each file and transfers only the contents that are different on
the replica side from production server. So you can use any application to
restore the files for creating manual replica creation. If they are restored
as close as they are in the protected server then DPM will transfers less
amount of data if they are different large amount of data, DPM ends
transfers the large difference. File/folder attributes, timestamps change
cause very less data to be transferred between DPM and Protected server.
Hope this helps you make your choice of creating manual replication.

Thanks,
Praveen D [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.

17-Mar-10 08:29 AM

Hi Praveen, thanks for the reply.  I am confused now, because this article
http://technet.microsoft.com/en-gb/library/bb808709.aspx clearly states "It
is crucial that when you restore the data to the DPM server to create the
replica, you retain the original directory structure and properties of the
data source, such as time stamps and security permissions."

So, if I want to avoid traffic accross a WAN, surely I need to preserve
timestamp data when creating the replica, otherwise the consistency check
will see every file as different and re-copy it accross my WAN?

17-Mar-10 09:28 AM

That???s a good point you are raising, If directory structure is
incorrect it will end-up transferring the entire file the reason is DPM
fails to find the file where it is expected. But when there is already a
file but time stamps or other file/folder attributes are different then it
will trigger the entire file verification including all file attributes(like
time stamps, security settings, file/folder attributes etc...) and its
contents. During this verification both places file data checksum are made
and compared(only checksum is transferred here), If the data is different
then it will transfer the file blocks that are different. In our case data
transfer will not take place over WAN since they contents are same though
they have the different time stamps. But the entire file contents will be
verified at block level using a checksum, which takes longer for
verification. This means it may take longer but it will not result in data
transfer over WAN. If time stamps are same then DPM do not trigger any
verification hence time is also saved here. If your worried about only
transfer over WAN then you may ignore the timestamp restoring. But if you
want to optimize on time to take also then you should restore timestamps,
security settings and other file/folder attribute etc... .  As documented
correctly pointed, the best thing is to restore everything as they are in
the protected computer to save time as well as data transfer. Hope now its
more clear

Thanks,
Praveen D [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.

17-Mar-10 10:48 AM

Thanks Praveen.  Is there a recommended way to copy the data?  Can I simply
use Robocopy with switches and copy it to the correct path, as per the
Technet document?  How does this work for say Exchange Information stores, as
I will need to copy those from remote offices to a central location?

18-Mar-10 06:37 AM

Yes you can use the robocopy with appropriate switches to copy the
files. But if you are using robocopy and want to copy over WAN then I would
rather recommend to let the DPM itself copy it over WAN. The reason even if
it fails DPM will do the needful bring the files in consistent state, only
caveat here is you might need to run the consistency check jobs multiple
times . On the other hand when you are copying files it might be possible
that files size and its content being changed by the time the copy finishes
it will anyhow end-up doing verification of entire file contents, this may
increase the total time to get the replica in consistent state. Here the
total time taken to get replica consistent state would include robocpy +
consistency check. The manual load is more useful when first time transfer
takes longer than the somebody shipping data over manually(for example, by
copying to tape and bringing tape to DPM location and restoring them back,
for large datasets/slow networks). I do not see a need for manual load if you
are copying over WAN where DPM itself can transfer the files in backup mode,
unless the network is very fragile to get the entire file transfer done in a
job where other manual tools can be run multiple times with retries in
network breaks to get a copy of the protected files. If you are worried
about WAN utilization going 100% by DPM itself, You can configure
appropriate network speed on the Agent management tab for protected servers.
Hope this helps you make your choice.

Thanks,
Praveen D [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights.

29-Jul-10 04:57 PM

I wish to use DPM 2010 to protect two small remote office and take the tape libraries out of the loop. Both these office are connected by a FRACT T1 so I have no other choice that to create manual replica's for all the data I want to protect.



The problem I run into is how to correctly create a manual replica of Exchange 2003. I have created the Protection group for our Exchange First Storage group but when I view the details to find the paths on the server protected (so I know what to copy over to the DPM server) just show the following:



Source (Protected server)



C:\ on hostname.of.server

E:\ on hostname.of.server

F:\ on hostname.of.server



I can see simply enough were on DPM to put the data, but I have no idea if DPM is trying to make a full replica of each disk?



Basically I am just not sure what directores/files DPM is pulling from to create the replica.