Error: leveldb: manife t corrupted (field ‘comparer’): missing [file=MANIFEST-344984]
First of all, running ipfs as root isn’t a good idea.
Setup a dedicated account for ipfs and run it with user rights.
Secondly, looks like your filesystem or your hardware maybe has an issue. Check your harddrive (smart data for example), look at the logs for IO errors and check the filesystem for integrity.
Also make sure you’re running ipfs on a filesystem with (at least) proper journaling - a copy on write filesystem with checksums like btrfs or zfs is probably preferable for the next installation.
I run all my IPFS installation on zfs just to make sure that the integrity is preserved even on a crash of the system.
I can’t really help with recovering a broken database, haven’t had the issue yet and therefore have no experience with it.
But this page might help you: