1st backup failed but I could still boot the phone
When backing up, it failed halfway, it failed backing up /data/.
I rebooted my phone and found that my keyboard doesn't remember my custom words anymore.
2nd backup failed and I can't start the phone anymore
I rebooted into the recovery and tried backing it up again the second time. It failed halfway, it failed backing up /system/. Then I tried the backup again (without rebooting) and it failed immediately saying no space on the SD card (I am not sure if it's true)
So I rebooted the phone and it is showing the boot animation forever (I waited over 30 mins).
I tried restoring /system/ from the first backup but it didn't help.
I don't even know where the problem is, how can a backup break your phone?? Any help will be appreciated.
boot-looptag, please check its tag-wiki for first aid. Btw: restoring
/systemwas pretty unnecessary here: as that's read-only, it wasn't changed in between. You should check your available free space on the SDCard (where your backups go to) and make sure you have about twice the space your other partitions consume ("twice" is kinda "safety margin"), as the Nandroid backup copies their images here.