FILE device type inefficient space usage for directory data.

Answer

To configure a file storage pool to more efficiently use space when small objects like directories are being stored to it, define or update the file pool with the option dataformat=nonblock. This will cause the allocations into this pool to be based upon the object size and not the normal 256K blocksize.

Alternatively there are a few other options that can be considered in an effort to avoid this inefficient space usage situation:

• Do not place storage pools used solely for directory data in device type FILE storage pools.
• Do not use a dirmc or archmc option to send directories to a unique device type FILE storage pool.
• Ensure that directory data is backed up in such a way that it can be aggregated. Running a backup with the -dirsonly option and then with the -filesonly option may help accomplish this. Over time (depending upon the nature of the client environment and the way directory objects may change), running standard incremental backups will result in changed directories not being able to be aggregated together. Therefore this problem cannot be completely avoided when running normal incremental backups (of both files and directory data) to a FILE storage pool.