[Huawei Nova/Nova Plus ROMs, Kernels, Recoveries, &] MysteryMan105:
[MENTION=4471434]#Henkate[/MENTION] I have installed the TWRP recovery and then went into it but when I wanted to backup my files before I root my device it says again that it is unable to mount /cache or storage... It is already a lot better than before though, as when I reboot my device it works normally without its saying that anything is corrupted or seriously damaged. I searched it up and apparently to fix the problem with being unable to mount /cache or storage, you just need to wipe your device in TWRP and then once its done "Format Data". I tried to do this but I had exactly the same problem I had when trying to backup my files, unable to mount /cache or storage. I just want to ask you if you by chance know a fix for this or if I should do something differently.

I am currently following a guide that was sent to me on Reddit:

"First we need to download the Android platform tools. These contain tools such as fastboot and ADB (Android Debug Bridge). You can download the latest version (as of 5/7/2017) for Windows here. Extract the "platform-tools-latest-windows.zip" file and there should be a "platform-tools" folder. Treat this as your working directory and download all other files to this folder. Now we need to download Team Win Recovery Project, or TWRP as most people call it. TWRP is a custom recovery. A recovery is a mini-OS that is stored on another partition of the device that can do basic functions like flashing and wiping. TWRP is one of the more full featured recoveries as it has stuff like backup and restore built in. Devices do have stock recoveries but these are programmed to only flash files signed by the vendor, people don't often notice this but stock recovery is what the device uses when you run an OTA (Over The Air) update or a factory reset. You can get the latest version (as of 5/7/2017) of TWRP for your device here. Please keep in mind this is an unofficial TWRP version. Now to download the part that actually roots your device. Normally I would recommend SuperSU however since you're on Marshmallow/Nougat I recommend Magisk instead. Using Magisk will allow you to hide root from apps that detect it and it would allow things like Android Pay to still work. It, along with a bunch of other things come in a flashable zip format that gets flashed using a custom recovery. You can get the latest version (as of 5/7/2017) here.

Now to prepare the device to be flashed with TWRP. Go into settings and look for "Developer Options" or something along those lines. If it isn't there, go into "About phone" and tap "Build number" 7 times. Then go back up into settings. They should be there now. Enable "Developer Options" (if it has a toggle) then enable "USB Debugging". This allows us to use ADB on the stock ROM but it usually isn't needed (we enable it just in case). Also enable "OEM Unlock" if it's there, this would allow us to perform the function that will allow us flash unsigned images to the device however not all builds have this setting so you may not need to enable it. Once you have these options set, shutdown the device.

Now to put the device into bootloader mode (also known as fastboot mode). Hold the Volume Down and Power buttons, once you're in bootloader mode release both buttons. Now plug the device in. Open command prompt to the "platform-tools" folder. Now type fastboot devices and it should return <SERIAL NUMBER> fastboot. If it doesn't then tell me because that means you probably have a driver issue. Now to unlock the bootloader. This will allow us to flash and run software not signed by Huawei. Huawei requires you to go through a process on their website to do this. Go here and follow the given instructions (ignore anything about the Android SDK as you already have the required parts for it, just run the given commands), note you will need to make a Huawei account. Once the bootloader is unlocked. Run the command fastboot flash recovery twrp_huawei_hwcan_20170218.img. Once that finishes shutdown the device with the power button. Now hold Volume Up and Power, release them when you see the Team Win Recovery Project (TWRP) splash screen."

(Note: I made it up until this point)

"It's going to ask you if you want to modify the system, you can just allow it to do this by swiping the slider. It may also ask you anytime during the process if you want to root or install the TWRP app, don't let it do this. Now click Backup and select "system", "data", and "boot". Now swipe the slider. Once it is done backing up run adb pull /sdcard/TWRP TWRP in command prompt to pull the backup to your computer. Now click "Advanced" and click "ADB Sideload". Swipe the slider, you don't need to wait for it to start as it will start once it gets the command from your computer. Now run adb devices in the command prompt. You should see something like <SERIAL NUMBER> sideload. If you don't then tell me because that means there is probably a driver issue. There is multiple methods to flash zips with TWRP but this is my favorite as it doesn't leave the files on the device. Now just run adb sideload Magisk-v12.0.zip to flash it. The percentage is inaccurate so don't worry if it goes over 100%. TWRP will say once it finishes. Then you could click "Reboot System" and it should boot normally."