пн, 11 янв. 2021 г. в 18:49, Tamara Schmitz <[email protected]>:
> On 06/01/2021 16:56, Matwey V. Kornilov wrote: > > Another consideration. Does anybody know any research on what FS is > > the most friendly to SD cards? > > I believe that would be FAT32 which is what the firmware is optimised > for but of course not very useful for a root fs. F2FS is a flash > optimised FS. > > One thing that I found out is that a lot of SD card vendors explicitly > have an expected start sector on SD cards. Internally SD card flash is > segmented into 4MiB blocks or something like that. Hence most SD cards > formatted so that the standard FAT32 partition starts at block 8192. The > Official Raspian Images respect this too by placing the boot partition > at sector 8192 (you can validate this with `fdisk -l /dev/mmcblk0`). > This could make a difference in performance. > This also may be important because some bootloader images are located before the first partition. For instance, u-boot.img is placed at 768 at beagle bone black. And currently only 655360 bytes are available for this image. It has already raised some booting bugs when u-boot.img didn't fit into this place and overwrote the first partition. > > I tried to test this by building an image locally but failed due to some > weird dependency issues. You should be achieve the alignment by changing > the <type> tag in the .kiwi like `<type image="oem" > disk_start_sector="8192">` > > I would like to benchmark and compare multiple FS as well as the > difference the alignment could do if I can get it to build. > > -- > Tamara Schmitz > SCC Team > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5 > 90409 Nürnberg > Germany > > HRB 36809, AG Nürnberg > Geschäftsführer: Felix Imendörffer > > -- With best regards, Matwey V. Kornilov
