[Samsung Galaxy Watch] adfree:
To dump "whole" eMMC...

Limitation we have only maximum 1,8 GB... so we have tiny problem to put whole 4 GB... ;)

To check free space...

Example taken from my SM-R760...

sh-3.2# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 1.3G 1.1G 200M 84% /
devtmpfs 340M 0 340M 0% /dev
/dev/mmcblk0p14 1.3G 1.1G 200M 84% /
/dev/mmcblk0p12 139M 85M 51M 63% /opt
/dev/mmcblk0p10 14M 253K 13M 2% /usr/lib/modules
tmpfs 352M 24K 352M 1% /dev/shm
tmpfs 352M 2.6M 349M 1% /run
tmpfs 352M 0 352M 0% /sys/fs/cgroup
tmpfs 352M 60K 352M 1% /tmp
/dev/loop0 384K 384K 0 100% /opt/share/zoneinfo
/dev/loop1 34M 34M 0 100% /usr/share/locale
/dev/mmcblk0p11 183M 101M 80M 56% /opt/system/csc
/dev/mmcblk0p2 6.8M 1.2M 5.0M 20% /csa
/dev/mmcblk0p13 1.9G 120M 1.8G 7% /opt/usr
tmpfs 71M 80K 71M 1% /run/user/5001
tmpfs 71M 0 71M 0% /run/user_ext/5001
/dev/mmcblk0p13 1.9G 120M 1.8G 7% /opt/usr/media
/dev/mmcblk0p13 1.9G 120M 1.8G 7% /opt/usr/apps
/dev/mmcblk0p13 1.9G 120M 1.8G 7% /opt/usr/home/owner/media
/dev/mmcblk0p13 1.9G 120M 1.8G 7% /opt/usr/media
sh-3.2# df -a
Filesystem 1K-blocks Used Available Use% Mounted on
rootfs 1298824 1064480 204612 84% /
devtmpfs 347224 0 347224 0% /dev
none 0 0 0 - /proc
sysfs 0 0 0 - /sys
/dev/mmcblk0p14 1298824 1064480 204612 84% /
/dev/mmcblk0p12 141376 86868 51276 63% /opt
/dev/mmcblk0p10 13847 253 13287 2% /usr/lib/modules
securityfs 0 0 0 - /sys/kernel/security
smackfs 0 0 0 - /sys/fs/smackfs
tmpfs 359712 24 359688 1% /dev/shm
devpts 0 0 0 - /dev/pts
tmpfs 359712 2628 357084 1% /run
tmpfs 359712 0 359712 0% /sys/fs/cgroup
cgroup 0 0 0 - /sys/fs/cgroup/systemd
pstore 0 0 0 - /sys/fs/pstore
cgroup 0 0 0 - /sys/fs/cgroup/net_cls
cgroup 0 0 0 - /sys/fs/cgroup/cpu,cpuacct
cgroup 0 0 0 - /sys/fs/cgroup/freezer
cgroup 0 0 0 - /sys/fs/cgroup/memory
debugfs 0 0 0 - /sys/kernel/debug
tmpfs 359712 60 359652 1% /tmp
configfs 0 0 0 - /sys/kernel/config
/dev/loop0 384 384 0 100% /opt/share/zoneinfo
/dev/loop1 34176 34176 0 100% /usr/share/locale
/dev/mmcblk0p11 187373 102462 81020 56% /opt/system/csc
/dev/mmcblk0p2 6907 1218 5117 20% /csa
/dev/mmcblk0p13 1936976 122612 1797980 7% /opt/usr
tmpfs 71940 80 71860 1% /run/user/5001
tmpfs 71940 0 71940 0% /run/user_ext/5001
/dev/mmcblk0p13 1936976 122612 1797980 7% /opt/usr/media
/dev/mmcblk0p13 1936976 122612 1797980 7% /opt/usr/apps
vip_cgroup 0 0 0 - /sys/fs/cgroup/vip
/dev/mmcblk0p13 1936976 122612 1797980 7% /opt/usr/home/owner/media
/dev/mmcblk0p13 1936976 122612 1797980 7% /opt/usr/media

Taken from here:

https://opensource.com/article/18/7/how-check-free-disk-space-linux

First attempt:

dd if=/dev/mmcblk0 of=/opt/usr/media/full4GB_eMMC.bin

dd stopps if usr partition is full...

Could lead to sideeffect...

But could be enough to pull result...

sh-3.2# dd if=/dev/mmcblk0 of=/opt/usr/media/full4GB_eMMC.bin
dd: writing to `/opt/usr/media/full4GB_eMMC.bin': [COLOR="Red"][B]No space left on device[/B][/COLOR]
3596569+0 records in
3596568+0 records out
1841442816 bytes (1.8 GB) copied, 151.265 s, 12.2 MB/s

sh-3.2# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 1.3G 1.1G 200M 84% /
devtmpfs 340M 0 340M 0% /dev
/dev/mmcblk0p14 1.3G 1.1G 200M 84% /
/dev/mmcblk0p12 139M 83M 53M 61% /opt
/dev/mmcblk0p10 14M 253K 13M 2% /usr/lib/modules
tmpfs 352M 24K 352M 1% /dev/shm
tmpfs 352M 2.5M 349M 1% /run
tmpfs 352M 0 352M 0% /sys/fs/cgroup
tmpfs 352M 60K 352M 1% /tmp
/dev/loop0 384K 384K 0 100% /opt/share/zoneinfo
/dev/loop1 34M 34M 0 100% /usr/share/locale
/dev/mmcblk0p11 183M 101M 80M 56% /opt/system/csc
/dev/mmcblk0p2 6.8M 1.2M 5.0M 20% /csa
[COLOR="Red"][B]/dev/mmcblk0p13 1.9G 1.9G 0 100% /opt/usr[/B][/COLOR]
tmpfs 71M 80K 71M 1% /run/user/5001
tmpfs 71M 0 71M 0% /run/user_ext/5001
[COLOR="Red"][B]/dev/mmcblk0p13 1.9G 1.9G 0 100% /opt/usr/media
/dev/mmcblk0p13 1.9G 1.9G 0 100% /opt/usr/apps
/dev/mmcblk0p13 1.9G 1.9G 0 100% /opt/usr/home/owner/media
/dev/mmcblk0p13 1.9G 1.9G 0 100% /opt/usr/media[/B][/COLOR]

sdb pull /opt/usr/media/full4GB_eMMC.bin
pulled full4GB_eMMC.bin 100% 1756MB
1 file(s) pulled. 0 file(s) skipped.
/opt/usr/media/full4GB_eMMC.bin 552 KB/s (1841442816 bytes in 3255.896s)

Pull seems 1 hour...

Best Regards