cancel
Showing results for 
Search instead for 
Did you mean: 

Reduce DBALL I/O

Creator
Creator

Hi there,

 

I searched everything, I think I tried a lot of things, but I can't seem to reduce the DBALL I/O in Nastran 9.1.

Is that even possible or is there nothing I can do?

 

Kind regards,

Jevin

2 REPLIES

Re: Reduce DBALL I/O

Community Manager Community Manager
Community Manager

Jevin20 wrote:

Hi there,

 

I searched everything, I think I tried a lot of things, but I can't seem to reduce the DBALL I/O in Nastran 9.1.

Is that even possible or is there nothing I can do?

 

Kind regards,

Jevin


I'm not sure if this is the answer you are looking for but below is what Help says (you can also this info directly here:

 

4.7 Understanding the .DBALL and .MASTER Files

 

The .DBALL and .MASTER files are database files (DBsets) that NX Nastran generates automatically

during a solve. The files are generated in the scratch directory. These files are necessary if you

want to later perform a restart analysis.

 

  • The .MASTER file is a directory of the database. It contains the names of all DBsets, DBset

members and their physical file names, and a directory of projects, versions, data blocks,

parameters, DMAP source and object files. It also contains the Nastran Data Definition Language

(NDDL) scheme used to describe the database. The default maximum size for .MASTER

is 5,000 blocks.

 

  • The .DBALL file contains all the DMAP data blocks you can save for reuse in a subsequent run.

In the solution sequences that don't allow restarts, such as SOL 101, this file is empty. The

default size is for .DBALL is 250,000 blocks.

 

Specifying Whether to Save .DBALL and .MASTER Files

 

The “scratch” option on the nastran command line allows you to specify whether you want the

software to save the files .DBALL and .MASTER files. By default, NX Nastran deletes the files

at the end of the run.

  • If you specify “scratch=yes,” the software deletes the files.
  • If you specify “scratch=no,” the software keeps the files.
  • If you specify “scratch=mini,” the software retains a reduced size database that you can use

to perform data recovery restarts.

 

See also

  • “scratch” in the NX Nastran Quick Reference Guide
  • “Mini-Database Restarts” in the NX Nastran User's Guide
  • “Understanding DBsets” in the NX Nastran User's Guide

 

Manually Deleting .DBALL and .MASTER Files

 

In some cases, you may need to manually delete the .DBALL and .MASTER files. For example:

  • If your solve doesn't complete successfully, NX Nastran may not automatically delete the .DBALL

and .MASTER files, even though you specified “scratch=yes.” In those cases, you must delete

the files manually before resubmitting your job.

  • If you specified “scratch=no,” but you decide that you want to submit a .dat file a second time as a

cold start (you don't use any restart commands), you must first delete the corresponding .DBALL

and .MASTER files before you resubmit the job.


Regards,
Ganesh

Simcenter 3D Community Manager
Simulation and Test Solutions

Re: Reduce DBALL I/O

Siemens Phenom Siemens Phenom
Siemens Phenom

The size of and the IO to the MASTER and DBALL cannot be altered. These are both typically small relative to the size of the SCRATCH files and don't have much of an affect on the total solution.