damaged files (mp3,txt , etc) on flash-drive

[Мистер Андерсон]

fdisk /dev/da0s1
******* Working on device /dev/da0s1 *******
parameters extracted from in-core disklabel are:
cylinders=233 heads=64 sectors/track=32 (2048 blks/cyl)

parameters to be used for BIOS calculations are:
cylinders=233 heads=64 sectors/track=32 (2048 blks/cyl)

filesystem : FAT32

mount_msdosfs /dev/da0s1 /usr/home/user/flash

usbdevs -v | grep "USB"
port 6 addr 2: full speed, power 500 mA, config 1, <USB PRODUCT>(0x8000), <USB MF>(0x066f), rev 10.01






for example :

(root)
# md5 Invasion_s01e06_DVDRip_RUS.avi
MD5 (Invasion_s01e06_DVDRip_RUS.avi) = 8e1240afd0601f082f8a718e461f1531

# cp Invasion_s01e06_DVDRip_RUS.avi /usr/home/fdkit/flash/

# md5 /usr/home/fdkit/flash/Invasion_s01e06_DVDRip_RUS.avi
MD5 (/usr/home/fdkit/flash/Invasion_s01e06_DVDRip_RUS.avi) = 533b5700c120b652a63079c5ff9ec386


I wish to notice that if to copy files in the size up to ~1mb that damages is not present.