DAOSTune estimation tool
DAOSTune is an application for estimating object size to help Domino administrators decide which minimum size to use for DAOS.
It scans a specified set of databases on a server and collects information about objects that potentially could be stored in DAOS. After scanning, it organizes these objects into “buckets” where objects of similar sizes are placed into the same bucket. Then, it displays information about these buckets as a table from which the you can see estimates about space savings and reasonable DAOS minimum object size suggestions.
It is important to understand that the actual number of DAOS objects that would be created or the amount of potential disk savings depend on the distribution of object sizes in your specific databases and the number of databases which share the same attachment.
Because there is no single "right answer," this tool analyzes the attachments for a specific set of databases and calculates the reduction in .nsf database storage, the amount of DAOS storage, and the overall disk space savings for a range of DAOS minimum object thresholds.
Our general rule of thumb is to try to find the threshold that provides 80% of the theoretical savings with 20% of the theoretical maximum number of DAOS files -- the 80/20 rule.
In the bucket table output, there is a column that denotes the minimum object size of that bucket. The more buckets specified, the more suggestions that are given (see the -buckets option in DAOSTune command line arguments). As the administrator, you can set the server’s DAOS minimum object size according to one of the suggested sizes based on which row’s estimates you like. The buckets listed on higher rows contain larger objects than those in lower rows. The first bucket contains the largest objects, and each bucket thereafter contains all the objects of the buckets before it, plus its own objects. The final and lowest bucket contains all the objects scanned.
Running DAOSTune does not change the state of the server’s databases, objects, or DAOS. The tool is safe to use in any way that you want, as it consumes only CPU resources and time.