[General Questions and Answers] Yakchimi:
i'ved found 3 files with fstab: fstab.rk30board ; fstab.rk30board.bootmode.emmc ; fstab.rk30board.bootmode.unknown!

now, i don't know in what file, or if is in all files, and in what line i need to change.

next i will code lines in files:

in first file fstab.rk30board:

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/dev/block/mtd/by-name/system /system ext4 ro,noatime,nodiratime,noauto_da_alloc,discard wait,resize
/dev/block/mtd/by-name/cache /cache ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/mtd/by-name/metadata /metadata ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/mtd/by-name/userdata /data ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait,encryptable=/metadata/key_file

/dev/block/mtd/by-name/user /mnt/internal_sd vfat defaults voldmanaged=internal_sd:auto,noemulatedsd
/devices/platform/rk29_sdmmc.0/mmc_host/mmc /mnt/external_sd vfat defaults voldmanaged=external_sd:auto
/devices/platform/usb20 /mnt/usb_storage vfat defaults voldmanaged=usb_storage:auto

in second fstab.rk30board.bootmode.emmc:

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK
/dev/block/platform/emmc/by-name/system /system ext4 ro,noatime,nodiratime,noauto_da_alloc wait,resize
/dev/block/platform/emmc/by-name/cache /cache ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/platform/emmc/by-name/metadata /metadata ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/platform/emmc/by-name/userdata /data ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait,encryptable=/metadata/key_file

/dev/block/platform/emmc/by-name/user /mnt/internal_sd vfat defaults voldmanaged=internal_sd:auto,noemulatedsd
/devices/platform/rk29_sdmmc.0/mmc_host/mmc /mnt/external_sd vfat defaults voldmanaged=external_sd:auto
/devices/platform/usb20 /mnt/usb_storage vfat defaults voldmanaged=usb_storage:auto

in the last fstab.rk30board.bootmode.unknown:

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/dev/block/mtd/by-name/system /system ext4 ro,noatime,nodiratime,noauto_da_alloc,discard wait,resize
/dev/block/mtd/by-name/cache /cache ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/mtd/by-name/metadata /metadata ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait
/dev/block/mtd/by-name/userdata /data ext4 noatime,nodiratime,nosuid,nodev,noauto_da_alloc,discard wait,encryptable=/metadata/key_file

/dev/block/mtd/by-name/user /mnt/internal_sd vfat defaults voldmanaged=internal_sd:auto,noemulatedsd
/devices/platform/rk29_sdmmc.0/mmc_host/mmc /mnt/external_sd vfat defaults voldmanaged=external_sd:auto
/devices/platform/usb20 /mnt/usb_storage vfat defaults voldmanaged=usb_storage:auto

so if it can help someone to solve my problem, i would be gratefull, thanks to any help!

i will attach files!