Do I have to compress a SD card every time I deleted a file?

FAQ #101494

In the manual for the file system it is recommended to compress a flash file system after a file has been deleted. This FAQ explains the differences between SD flash systems such as the PCD3.R600 equipped with PCD7.R-SDxxx and the PCD7.R55x and PCD7.R561 modules.

 

Introduction
In the manual for the file system it is recommended to compress a flash file system after a file has been deleted. This is strongly recommended for the PCD7.R5xx modules, INTFLASH etc. because for these systems the compress is used in order to make "freed" memory available again.
The SD cards used in the PCD3.R600 or the PCD2.R6000 are equipped with an own controller which automatically makes "freed" memory available again. On the other hand, the free memory (where data has been deleted) will remain at its place. This leads to "holes" in the used memory structure which is not ideal (because of increased time used for the initialitation of the card on start up). The compress task will remove these "holes" in the memory.

Conclusion
A "compress" is not necessary for making memory space from deleted files available on SD cards. But the compress optimizes the memory usage and should be done from time to time.
As it is easyer to program the compress right after the deletion of a file, this is the easyer way to realize this recommendation. 

 

Categories

PCD7 / Rxxx

PCD3 / Rxxx

PCD2 / Rxxx

Last update: 01.06.2015 01:21

First release: 18.08.2010 13:36

Views: 8817

The requested software / document is no longer marketed by Saia-Burgess Controls AG and without technical support. It is an older software version which can be operated only on certain now no longer commercially available products.

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