ehcache large file sizes

At penn we have run out of space in prod on a disk, due to huge ehcache file sizes….

rw-rr-. 1 appadmin users 41189380 Jan 22 08:12 MembershipEntry.data
rw-rr-. 1 appadmin users 44819583 Jan 22 08:26 edu.internet2.middleware.grouper.internal.dao.hib3.Hib3GroupDAO.FindByUuid.data
rw-rr-. 1 appadmin users 41424661 Jan 22 08:27 edu.internet2.middleware.grouper.Group.data
rw-rr-. 1 appadmin users 311635283 Jan 22 08:28 edu.internet2.middleware.grouper.internal.dao.hib3.Hib3MemberDAO.FindBySubject.data
rw-rr-. 1 appadmin users 1433472972 Jan 22 15:14 edu.internet2.middleware.grouper.Member.data

And member is configured like this:

cache.name.Member.name = edu.internet2.middleware.grouper.Member
cache.name.Member.maxElementsInMemory = 1000
cache.name.Member.eternal = false
cache.name.Member.timeToIdleSeconds = 1
cache.name.Member.timeToLiveSeconds = 1
cache.name.Member.overflowToDisk = false
cache.name.Member.statistics = false

Why would this be 1.4gig????

Am I missing something? How do we address this?

Thanks,
Chris