Try following:
" eMMC on its own does not track write cycles like standard drives and does not have mechanism like smart. You can use mmc extcsd read /dev/mmcblk0 from package mmc-utils to take a peak in to amount of used reserved blocks. That is field EXT_CSD_DEVICE_LIFE_TIME_EST. Value is in range of percents so 0x01 is from 0%-10% blocks used, 0x02 is from 10%-20% and so on. When amount of reserved block used is close to 100% then NAND is pretty much EOL."
For example from my omnia:
root@turris:~# mmc extcsd read /dev/mmcblk0 | grep EXT_CSD_DEVICE_LIFE_TIME_EST_TYP
eMMC Life Time Estimation A [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]: 0x01
eMMC Life Time Estimation B [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_B]: 0x01
root@turris:~#
I use a USB harddisk and configured persistent logfiles. I do run pakon, but IIUC in my configuration it uses the external disk…
In retrospect the Omnia should IMHO have opted for a replaceable SD card over eMMC, but I admit that at the time eMMC looked pretty attractive (and who knew back then how much life was actually in the omnia’s design).
P.S.: Things like EXT_CSD_DEVICE_LIFE_TIME_EST tend to not degrade nicely linearly, but initially very slowly, but once it starts things can avalanche into full failure rather rapidly.