Although SAN Health is capable of concurrently auditing a very large number of switches, it has only been tested and is supported against a maximum of 100 switches running concurrently. This is not a factor of fabric size, only the number of switches. Because the safety of production fabrics is critical, SAN Health has been set not to allow concurrent audit sessions of more than 100 switches at once.
If you have more than 100 switches to analyze, you can run SAN Health against logical groups of switches. Select the switches on the basis of complete fabrics or groups of fabrics in each session. Each audit that you run will result in a separate SAN Health report and Visio diagram. If you have six fabrics of 20 switches each, it would make sense to audit these in whole fabric or SAN increments, resulting in a Visio diagram and report for your particular logical grouping.
Another limitation in auditing more switches is the resulting report file sizes. The spreadsheet can end up with hundreds of sheets in the workbook, each one potentially many hundreds of rows long. This can result in a file size that is many dozens of MB in size and becomes unweildy to open and manipulate, bogging down even fast workstations.