You can change the percent of disk space reserved for Snapshot copies by using the snap reserve command.
You must ensure that there is sufficient Snapshot copy reserve space allocated for the Snapshot copies. The space must not be so less so that it consumes active file system space and must not be so large that it wastes space that could be used by the active file system. Be default, for traditional volumes, the Snapshot copy reserve is set to 20 percent of the disk space and for FlexVol volumes, the Snapshot copy reserve is set to 5 percent of the disk space.
percent is the percent of disk space you want to reserve for Snapshot copies.