# Problem with rootfs update with \*.mender **URL:** \ **Category:** General Discussions\ **Created:** [June 14, 2021, 7:40am UTC](https://hub.mender.io/t/problem-with-rootfs-update-with-mender/3742 "2021-06-14T07:40:26Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![buffo](https://yyz2.discourse-cdn.com/flex036/user_avatar/hub.mender.io/buffo/32/909_2.png) [@buffo](https://hub.mender.io/u/buffo)\ **Post date:** [June 23, 2021, 7:54am UTC](https://hub.mender.io/t/problem-with-rootfs-update-with-mender/3742/9 "2021-06-23T07:54:24Z")
Okay, I found out some more things. When flashing my NAND via u-boot I have two different possibilities: either I use the `nand write` or the `nand write.trimffs` function (which is also handled here: [clicky](https://hub.mender.io/t/ubifs-ecc-errors-after-adding-mender-to-toradex-imx6ull-image/1767/6), more infos: [clicky](https://microchipsupport.force.com/s/article/How-to-program-the-rootfs-into-nandflash-through-u-boot-for-SAM9x5-or-SAMA5D3x)). The first one will lead to a successful boot, but I cannot reboot then due to a `ubi_io_read error.` with lots of ECC errors. BUT: the checksum of the `ubi0_1` volume matches then the one from my host build. On the other side, the second command will lead to a perfectly fine reboot, but the checksum differs (as 0xff data at the end of pages will not be written to the NAND flash). As a result (and as far as I can see) I either have to fix my reboot issue with the normal `nand write` OR ensure that the kernel writes in a `nand write.trimffs` mode … --- _[View the full topic](https://hub.mender.io/t/problem-with-rootfs-update-with-mender/3742)._