File Layout

FMDS stores data using multiple archive files. These files are stored in the following directory: <rootdrive>:ttdatfilesfmdssafe



A database that stores all of the data collected by FMDS. When FMDS is running, this is a read-only file.


A file that stores accumulated FMDS data. FMDS flushes accumulated data to this file every five minutes or every 250000 records, whichever comes first.

Like the SafeStore.dat, the Warm.h5 file is a read-only file. It will only be writable by the automatic flushing process


A backup file FMDS creates prior to flushing the accumulated data to the Warn.h5 file to ensure data is not lost.


An archived file FMDS creates once the Warm.h5 exceeds 150MB (by default). A typical archive file name is: archive_2009-05-04-0002.h5, which is the second archive created on May 4, 2009.

Archive files are never opened writable except when deleting stores using FMDSFileMonkey.