Writing to mmcblk0p1 concerns


Not really sure where to put this. After reading concerns about wearing out the built in flash, I decided to add the Disks monitor to see how often mmcblk0p1 is written to. I set up the block_dump debugging outlined here and left it on for a little over 10 hours.

I found that a few processes write to the disk.

Kresd writes to it once every 1:20:21 (one hour, 20 minutes and 21 seconds)
btrfs-transaction writes to it much more often, every 30-45 seconds, 2-13 writes each time with 256 sectors
kworker/u4:4 writes to it randomly every 0-30-ish seconds with 8 sectors, 150-270 writes each time.

Does this seem like normal activity?

It does seem like a lot of writes, but I don’t really know. In my past experience with OpenWRT, this sort of thing was dealt with using overlay filesystems on USB drives. Otherwise, I don’t think the flash space was written much at all.


this situation is probably caused by the older kernel in TOS 3.11.x. In TOS 4.x/5.x this is fixed by commit which is part of 4.14 Kernel

So this should be fixed by upgrading to TOS 4, but just to be sure, I created an issue for this topic.

eMMC - live span, health monitoring

Until now I’ve only read about TOS 4.x - so what is 5.x about? Do you have a roadmap somewhere publicly accessible?


4.x is based on OpenWrt 18.06, 5.x will be based on OpenWrt 19.0X. I’m not aware of any publicly available roadmap right now.


Would be nice to have some sort of ETA - you used to have this in the beginning of this project…