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CPS (more)

Steve_Samoransk
Level 4
When a file is changed and CPS "copys" the change to its backup destination. Is it copying the entire file or only bit level changes?

Thanks

Steve
18 REPLIES 18

Jared_S_
Level 6
Employee
Hi Steve -
 
In CPS when a file is changed CPS copies the entire file not at the bit level. On the Business Server, filter drivers record all the changes made to files that qualify for backup in the Outbound Journal. File changes recorded in the Outbound Journal on the Business Server are sent to the Inbound Journal in the Continuous Protection Server or CMS. On the CMS, filter drivers apply the file changes from its inbound Journal to disk and prevents users from writing to backup destinations when its associated backup job is running. This is in a nutshell of how CPS works.
 
- Jared
 

Steve_Samoransk
Level 4
Thank you for the response. (not that it was the right one Smiley Happy ) I would hope to think that this would change in future versions.  We are looking to do CPS across the WAN and that would be rough with the full file changes.
 
Thanks

Nick_Pearce
Level 3
Jared, I would hope that your answer is in-correct, when we were sold BE CPS I was assured that the changes were captured at the bit level & not at the file level... please confirm

Message Edited by Nick Pearce on 05-03-200709:50 AM

Jared_S_
Level 6
Employee
Hi Nick -
 
Steve - I apologize for the misinformation. Nick you are correct. In further investigation I noticed they changed this from 10d. In the 11d CPS admin guide it states:
 
Continuous backup jobs use a filter driver to capture changed bytes in the data files on the source and move the changed bytes to the backup destination whenever the information changes. CPS takes snapshots of the backup destination at scheduled intervals.
- page 66
 
Also
 
Filter drivers capture changed bytes in files and copy the changed bytes to the destination. Snapshots of the destination are taken at regular intervals. Each snapshot is saved for 24 hours unless you specify otherwise.
- page 87
 
Here is a link to the CPS 11d Admin guide with further information:
 
 
 
 
 

Steve_Samoransk
Level 4

Well that is good news. Jared, you kind of opened a can of worms though... So even in testing i still notice a lot of data transfer even when i make a 1 letter change to a 1 k txt file. It still copies about 5 MB across to the Protection Server. Any thoughts as to that? is there any overhead its doing?.

 

Next Question: For a DR scenario. Is there a better practice then what i am about to describe.

 

Server in Site A (protected server) Crashes

Share out Live CPS data on Site B (Protected Server)

Users make changes to data

Server is rebuilt offline.

Copy of Data from Site B is sent to Site A and put back on Protected Server (offline)

Stop user access for Site B

Take Snapshot of Site B

Turn on CPS Job between Site A and B

After Sync is done Do a restore from the previous taken snapshot from Site B to A (From Protection Server to Protected Server) the protected server should then have all changes made while server was offline.

 

This works but is there a better way?

 

Also I read that above Post saying build 7170 is crashing alot and the user recommending Microsoft DPM...
So a couple questions . 1 Where can i get build 7170 (live update isnt downloading it) and 2. Your thoughts about Microsoft DPM? why is CPS better?

 

Thanks sorry for the loaded post.

 

 

 

 

Steve_Samoransk
Level 4
Please note in the above post that Site B is the PROTECTION server (not protected) and Site A is a protected server.

thanks

Jared_S_
Level 6
Employee
Steve -
 
The supported configuration of CPS allows exactly what I am interpreting; that you are restoring non-manipulated data in the backup destination to the restored server, then copying any new data that was created between the last backup from your temporary server to your rebuilt server.
 
Here is a good tech note to reference to when restoring a File Server using CPS:
 
As for your other questions:
 
You can install 7170 from the following location: www.backupexec.com
Be sure to select Trialware beneath Backup Exec for Windows header
You may be prompted to enter some information but its not much - just follow the prompts until you get to the download portion for Backup Exec. Do not worry about your existing licenses for 6235 as 7170 will overwrite on top of it even though your downloading from a site that indicated "Trialware". 7170 will be licensed after installing because of this.
 
I have researched Microsoft DPM a little but not enough to shed light on what it can or cannot do compared to CPS. Microsoft DPM still appears to be a beta release and has been only available since September 2006. I do know CPS offers several positives in continuously backing up and restoring your data. Some key features in CPS is Web Retrieval of Data which lowers the restore workload for the Admin, full system restores, and point-in-time snapshots are a few to note. CPS's smartlink option also gives you the ability to view CPS logs from the Backup Exec Interface. The CPS Admin guide is a good reference to what CPS can offer your backup environment.
 
I hope this information helps.
 
- Jared
 
 
 

Steve_Samoransk
Level 4
Jared, Thanks again for the response. Is there a technote on the differences between the 6325 and 7170 builds? also a good way to upgrade the MMS's  from the caso? (is it possible to do that?)
 
Thanks

 

Nick_Pearce
Level 3
Thanks for the update Jared, you had me worried for a moment there!!

Steve_Samoransk
Level 4

Jared, I am a little concerned. We have been vigorously testing the bit level changed and have noticed that it sends the full file every time. For instance

We have a 2MB Power Point Presentation

I change 1 letter on 1 slide and save and 6 MB gets transferred to the Protection Server.


We have verified this with our netflow device.


Suggestions?

Steve_Samoransk
Level 4
Just to add... It seems like no matter what file .. It copies double the actual file size from the protected server to the protection server.
 
This is not looking good.
 
Again Suggestions?

Jared_S_
Level 6
Employee
Steve -
 
Could there be any third party software accessing those files to reset the flag and in essence causing the whole file to be copied over?
 
This can sometimes be caused buy antivirus software.
 
- Jared

Jared_S_
Level 6
Employee
Steve -
 
Here is more information regarding your inquiry about 6235 and 7170 and the best way tp upgrade MOMS from the CASE. Here are some articles I think will help:
 
Here is a link to the new features in Backup Exec:
 
Here is a couple articles related to the CASO option in Backup Exec:
 
Procedural Guidelines for Upgrading CAS (Central Administration Servers) and MMS (Managed Media Servers)
 
 Backup Exec 11d Best Practices Guide: Central Administration Server Option (CASO)
 
I hope these articles address the answers you were after!
 
- Jared

Steve_Samoransk
Level 4
No 3rd party software. The fact that it is actually sending double the size of the file that is being modified is really weird. Is there a way i can see this "flag" and dig down into CPS to see excatly what is taking place? where is the flag to see if its being reset?

Thanks

Hywel_Mallett
Level 6
Certified
Steve, with respect to your DR scenario, I can't help but feel that CPS might not be the best option for what you want. I think you might be better off with a bit-level replication program.
For large budgets, Veritas Storage Foundation with the Volume Replicator option (possibly linked to a global cluster with Veritas Cluster Server).
For a more modest budget, I think that Replication Exec might be just what you want. It's similar to CPS, but you can easily convert your secondary into a primary, and vice versa.
Note that I haven't used CPS in a production environment myself.

Steve_Samoransk
Level 4
Hywel, Thanks for the input. When describing the DR situation It was just a request to see if there was a best pratice with CPS THe way i described it workes well. Also according to the CPS manual it is supposed to be BIT level changes being sent. I will definatly take a look at these other products .
 
Thanks again

Jared_S_
Level 6
Employee
Steve -
 
At this point I would suggest contacting support and having one of our technicians gather some debug logs to find why your CPS data is double the amount registered. The closest we could get to seeing what is going on without getting engineering involved, is through the various log producing tools Backup Exec already contains - SGMon, VxGather and such. A support technician will be able to assist you in producing these.
 
- Jared
 
 

Steve_Samoransk
Level 4
Yea i think your right. Ok I will open a ticket and then post the results when i get them...

Thanks again