There are three timeout processing attributes that specify when z/OS NFS will release a data set following certain NFS operations. The readtimeout and writetimeout processing attributes specify how long z/OS NFS will wait after respective read and write operations before releasing a data set. The attrtimeout processing attribute specifies how long a data set will remain allocated after an NFS Get Attribute or Lookup operation. When accessing data sets that are not DFSMS-managed with the nofastfilesize processing attribute, it may be advantageous to increase the attrtimeout value so that z/OS NFS caches data set attributes for a longer period of time. However, all three processing timeout attributes must be within the range of the maxtimeout and mintimeout site attributes.