The "System of Files Flash with support to Deals" (or JFFS) is a system of files based on a structure of records NOR uses on memoirs Flash on the part of the company Axis Communication AB. At present, it has been replaced for JFFS2.
Adding an abstraction level more, JFFS treats to the memoirs flash as a file of circular record. All the changes in files and directories are written in the head of the record in nodes. In every node, a head that contains the metainformation the information themselves is written first and later. The nodes are encandenados for a top displacement in the head. All the nodes begin as valid to turn in obsolete when their new version is created.
Between the head and the tail of the record stays the remaining free space of the system of files, when little of this one stays, a garbage recollector copies the valid nodes of the head to the tail, jumping the obsolete ones, therefore obtaining space.