In addition to refining the source dataset through the included and excluded directories, file matching further refines the selected source dataset for replication, as displayed in the following figure.
A SyncIQ policy can have file-criteria statements that explicitly include or exclude files from the policy action. A file-criteria statement can include one or more elements, and each file-criteria element contains a file attribute, a comparison operator, and a comparison value. To combine multiple criteria elements into a criteria statement, use the Boolean ‘AND’ and ‘OR’ operators. Any number of ‘AND’ and ‘OR’ file-criteria definitions may be configured.
However, when configuring file matching criteria, it is important to recognize the impact they have is dependent on the SyncIQ ‘Action’ selected above. If “Copy” was selected, more settings are available than “Synchronize” policies.
In both Synchronize and Copy policies, the wildcard characters *, ?, and  or advanced POSIX regular expressions (regex) may be utilized. Regular expressions are sets of symbols and syntactic elements that match patterns of text. These expressions can be more powerful and flexible than simple wildcard characters. Isilon clusters support IEEE Std 1003.2 (POSIX.2) regular expressions. For more information about POSIX regular expressions, see the BSD manual pages. For example:
Note: With a policy of type Synchronize, modifying file attributes comparison options and values causes a re-sync and deletion of any non-matching files from the target the next time the job runs. This does not apply to Copy policies.
Copy policies also allow an administrator to select files based on file creation time, access time, and modification time.
Note: Specifying file criteria in a SyncIQ policy requires additional time to complete, degrading overall SyncIQ performance. Conversely, if the source directories are refined using the “Included” and “Excluded” directories option, as stated in Source cluster directory, performance is not impacted to the same degree as specifying the file criteria. However, depending on the configuration, “Includes” and “Excludes” could also impact performance significantly. If possible, the first preference is to create policies without includes, excludes, and file criteria. The second preference is to use includes and excludes and finally, the last preference is file criteria. As a best practice, test the impacts of file criteria, includes, and excludes in a lab environment to confirm performance, prior to a production cluster update.