Specify the number of seconds used as a default for the sync daemon interval; this indicates how long the mount operation will wait before hardening meta data. When the sync daemon is active, the meta data for a file system is hardened. Specifying the value 0 indicates that the file system should harden meta data synchronously with syscall requests. (Note that a value of 0 causes the system to perform more slowly.) The maximum value that can be specified for t is 65535. The default is 60 seconds.
Sync interval values are rounded up to the next 30-second value. For example, specifying 31 seconds results in a sync interval of 60 seconds.