Disk-based Storage Total capacity

[Gonz]

I am using Backup Exec 2012 with a Data Domain system that has in total (3.6 TB)

I am using the Data Domain for creating 2 CIFS shares.

From Backup Exec I create 2 "Advanced File Type Devices" pointing to each of those shares.

Each time I create and "Advanced File Type Device", the reported size is 3.6 TB (the total size available).

The Disk-based Storage reported by Backup Exec is 7.22 TB which is clearly incorrect as the total size of the Data Domain is 3.6 TB

Is not Backup Exec aware that both of those "Advanced File Type Devices" are pointing to the same device and the space is shared?

Can someone clarify how it works?

Thanks in advance.

[Gurvinder]

It seems to think of the disk storage configured on 2 different drive and is summing it up. Will have to test this out. I hope BE 2012 is updated with the latest patches ?

[Gonz]

Hello Gurvinder.

Yes, you summarized properly the problem.

Backup Exec 2012 is not able to identify that both disk are located in the same machine.

So it is summing up when clearly it should not.

Any help will be appreciate it.

Kind Regards

Gonzalo

[CraigV]

Guys, go read up on Data Domain. It's a different kettle of fish to a normal disk-based storage. Don't forget the compression involved with DD when using CIFS shares as deduplication is used like this.

I am sure you will then understand how, and why, BE 2012 shows what it does when you understand Data Domain.....

[Gonz]

Hello Craig

Your comment "I am sure you will then understand how, and why, BE 2012 shows what it does when you understand Data Domain....." does not apply here and, in my personal opinion, is not accurate at all...

I do have knowledge of Data Domain.

Data Domain Compression and inline deduplication is not involved in this problem at all.

The problem occurs just adding the Disk Based Storage without adding any content to it.

Deduplication is not involved. As simple as that 

In fact you can remove Data Domain from the equation and the problem will be still there.

Is very simple.

Just create 2 CIFS shares on a Windows machine and add those CIFS shares as Disk-Based Storage.

You will notice then that the total capacity shown by the Storage Status just is the sum of the size of the space available in the 2 CIFS, when it should not as they are pointing to the same device.

In other words: If you have a Windows machine with 2 TB of disk and create two shares and two disk based storages against those CIFS, the size reported by Backup Exec cannot be 4 TB but 2 TB.

I hope you fully understand the problem right now

Gurvinder understood it and he is in the right direction

[CraigV]

Thanks for explaining...I struggle to understand little information

You're an employee so should have more than adequate information on the backend, or Admin Guide, Known Issues etc to check up on too surely?

[Andrew_Madsen · Accepted solution]

The Data Domain is not like a regular NAS or even a Windows share with Quotas involved. EACH volume reports to the query as having the full amount of disk space. Until you add space to the volume then you will notice the capacity goes down X2. If you were to create two shares on a Windows machine with 2TB and not add quotas (Thus a hard limit to the size of the volume) and handed it up to your server both share do indeed have the same amount of data available to them. The CIFS machine does not know if one or the other volume will fill up or not so it reports that the two volumes have 2 TB available to it. BE does not know how much disk the machine has. It just knows what the potential volume size is for the two volumes thus 4TB.

Where it problem is the Data Domain device is not building set volumes sizes but allowing all the room in the file system for the share.

[CraigV]

Thanks very much for the good clarification! :)

[Gonz]

Brilliant

Thanks a lot.