https://devzone.nordicsemi.com/f/nordic-q-a/45135/save-data-to-application-data-area-and-share-with-bootloaderHi all, I using nrf52832 , sdk 15.1 - My app include : application + bootloader + application data area - application define appliation data area is 12K byte (FDS_VIRTUAL_PAGES 3 , FDS_VIRTUAL_PAGE_SIZE 1024) - bootloader define NRF_DFU_APP_DATA_AREA_SIZEen-USTelligent Community 13Mon, 25 Mar 2019 09:11:07 GMThttps://devzone.nordicsemi.com/thread/178022?ContentTypeID=1Mon, 25 Mar 2019 09:11:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4745d96e-7406-4c33-b594-46210d3113a4Sigurd<p>Hi,</p> [quote user=""]- In bootloader ,&nbsp;<span>nrf_dfu_flash already has a fstorage instance that conflicts&nbsp;if I add FDS library to bootloader.</span>[/quote] <p>&nbsp;What error code/message did you get? Did you create a new fstorage instance ?&nbsp;</p> [quote user=""]- When I save data to application data area, and restart to bootloader, Bootloader can override data to this area. I want to avoid this. So How to calculate a application data&nbsp;satisfy the conditions : application can save, remain when reset, not override by bootloader, bootloader can read, and when&nbsp; update firmware, It not be erase by this process.&nbsp;[/quote] <p>&nbsp;Where are you saving the application data? Note that the&nbsp;<span>Peer Manager uses FDS to store bond information at the already reserved pages(FDS_VIRTUAL_PAGES). If you want to store your your own data, you need to increase&nbsp;NRF_DFU_APP_DATA_AREA_SIZE.</span></p><div style="clear:both;"></div>