Microsd Card Recording; Introduction - Mobotix D26 Dome Manual

D26 Camera Manual: Operating the Camera
Flash memory devices: more
robust than hard drives
92
3.5

MicroSD Card Recording

3.5.1 Introduction

Flash-based storage devices (MicroSD cards, USB sticks and solid-state
drives) do not contain any moving parts as compared to the com-
monly used hard drives. Flash-based storage devices are compact and
highly resistant to moisture and vibrations. They feature low energy
consumption and they do not lose any data in the event of a power
failure, meaning that they are ideal for use with MOBOTIX cameras.
Number of Write/Delete Cycles Per Flash Storage Cell
The number of write/delete cycles of every storage cell of a flash device
is limited. The controller of the flash device automatically detects indi-
vidual flash cells that are no longer functioning. The contents of the faulty cell will then be
rebuilt using a checksum and will be moved to a properly working spare cell. The faulty
storage cell will be marked as "bad" and will no longer be used. No data is lost in this process.
In addition, MOBOTIX cameras constantly monitor activated flash storage devices. MOBOTIX
has developed a technology to test the wear of the flash device by logging the number of
write/delete cycles (patent pending). The flash memory wear is automatically displayed
in the status bar in the live camera image but it can also be viewed at any time in the
Admin Menu > Camera Status dialog box.
Conservative Memory Usage Thanks to MOBOTIX MxFFS File System
MxFFS formatting of the MicroSD card means that MOBOTIX camera software will use the flash
device as evenly as possible, thus allowing for the maximum possible number of write/delete
cycles. This also means that all storage cells of the flash device will be written and deleted
with the same frequency, if possible. MOBOTIX technology increases the life of the flash
device considerably and also improves the security and the reliability of the storage process.
Storage Requirements and Life Expectancy of MicroSD Cards
The life expectancy of a MicroSD card increases proportionally to the storage capacity, since
the camera software will execute fewer write/delete cycles on each storage cell. The first
deletion will begin once the SD card has been filled to capacity (first full cycle).