While flashing the factory images of our Nexus devices, we get the Fastboot error: mke2fs failed, Cannot generate image for userdata. Or, in detail –
Couldn't parse erase-block-size '0x'. Couldn't parse logical-block-size '0x'. mke2fs 1.44.6 (5-Mar-2019) /tmp/TemporaryFile-HqqlrY: Unimplemented ext2 library function while setting up superblock /usr/lib/android-sdk/platform-tools/mke2fs failed with status 1 mke2fs failed: 1 error: Cannot generate image for userdata
Remove “-w” from the fastboot update command
In flash-all.sh script file, you must have noticed few line of code resembling –
fastboot oem unlock fastboot erase boot fastboot erase cache fastboot erase recovery fastboot erase system fastboot erase userdata fastboot flash bootloader bootloader-grouper-4.23.img fastboot reboot-bootloader sleep 10 fastboot -w update image-nakasi-ktu84p.zip
All you have to do is – remove “-w” option from the last line. Then save the script and execute it again.
fastboot update image-nakasi-ktu84p.zip
Fastboot is basically a command line utility which is used for flashing and booting Android devices. Here, “-w” option is used to erase both cache as well as user data. The utility option can format the partition type too. Since, the commands for erasing user data and cache (i.e. fastboot erase cache and fastboot erase userdata) are already present in our script file. So, apart from formatting the partition (of supported type) there is nothing more the “-w” option does. In that scenario, we can safely ignore the option.
For man page of fastboot –
Scroll down the man page of fastboot to get yourself acquainted with more options. Or, you could simple run the following in terminal –
In conclusion, Fastboot error: mke2fs failed, Cannot generate image for userdata could be resolved by removing the “-w” option from the fastboot update command line section provided with the script.