how to size BMR backups

[manatee]

NBU 7.5.0.5

how does one size a BMR backup?

i need to backup 22 Windows servers of diffrent configurations and want to find out how much space it'll need.

[RamNagalla]

so are you looking for space for Netbackup and BMR DB  or the space requirement to store the backup images?

start it from here Designing your backup system 

[manatee]

space required to store the BMR images.

given the RAM size, hd size, number of hd per server, how does one calculate the BMR image size for it?

[RamNagalla]

From 7.5 BMR admin guide.

"Depending on the operating system for which an SRT is created, the SRT requires
100 MB to 600 MB of disk space."

and for BRM backup images, it depends on the size of the data and frequency and the retection of the backup images.

use below technote to get that calucation

http://www.symantec.com/business/support/index?page=content&id=HOWTO99747#id-SF0S0114802

[manatee]

catch 22.

"..and for BRM backup images, it depends on the size of the data and.." precisely the size of the data is what i'm trying to find out.

if i'm going to backup sql databases it's easy to find the size of the data. but i'm going to backup a whole VM so how does one measure the size of the VM?

[jim_dalton]

The bmr component is minimal.

The db and associated are <1G total covering 14 servers, all windows in my env.

Tha backup itself generates a file describing the server whose name I cant remember. That too is tiny.

I would question the use of BMR and VMs but I'm sure its valid. We dont backup any VMs with NB client, we use snapshotting and SMVI.

BMR is targetted at physicals really.

Jim

[manatee]

snapshots and SMVI?

the purpose of BMR is to have a golden backup of a VM in case of disaster we can "easily" recover and restore the failed VM.

[jim_dalton]

Snapshots and smvi and snapmirror will also do that in case of disaster. 

I'm sure youve evaluated what else you'll need to recover if you have DR and you want to use Netbackup.

We have eliminated NB entirely from our P1 disaster recovery.

Jim

[Jaime_Vazquez · Accepted solution]

The amount of space that a client backup takes is not directly associated with the fact that BMR is enabled in the policy. Enabling the BMR option enables TIR with move detection.  That will increase the size of the backup image space for the TIR actions,. However, that is all an NBU activity, not a BMR activity.

When BMR is enabled, it will cause the client to generate a new client configuration file (called bundle.dat) ahead of the actual backup of the files.  This becomes the input to the BMRDB. Because BMR extracts device driver sets from the client during this process, the file BMR_DATA.db will grow faster than if only Unix/Linux clients are being backed up as it holds the actual driver file binaries.

The initial total size of the BMR databases is under 60 MB. As client updates are being added, the file sizes will begin to grow.  I have seen BMRDB files in the 1GB+ range, but those installations has hundreds of Windows clients. BMR only tries to keep the latest version of the configuration information and deletes previous versions.from the database.  However, as it does not reuse Configuration ID numbers (they keep growing numerically) and does not reuse database space, the files naturally grow. See the NBU command nbdb_unload for information on unloading and reloading the data content of a BMRDB. that helps compact the BMRDB files.

You can also reset the BMRDB to new by running "bmrsetupmaster -force -redo".  That will reinitalize the included data but the files are at their original start up sizes. Information on rebuilding the BMRDB can be found here:

Rebuilding the BMR database (BMRDB) 
http://www.symantec.com/docs/TECH212536

File space usage  for an SRT is OS dependent but it has no bearing on the backup image size. The file space used is on the Boot Server only.  There is no database component on a Boot Server.