[Filligree]

When you're transferring files and need to cope with corrupted/missing chunks, you should use a parity scheme. Others have mentioned that; it's common for, for example, Usenet.

If you can't control the underlying storage, then ditto. Keeping and maintaining explicit parity chunks is somewhat inconvenient, but it works.

But if you just want to avoid bitrot of your own files, sitting on your own HDD, I'd recommend using a reliable storage system instead. ZFS or, at higher and more complicated levels, Ceph/Rook and its kin. That still offers a posix interface (unlike parity files), while being just as safe.

[planteen]

If I am using a single HDD, can ZFS still add parity data? That's neat if it can. I assumed parity with ZFS was for something like RAID6 where there are multiple HDDs in a set.

Do any other file systems other than ZFS support adding parity in a single HDD config? Last I checked getting ZFS in Linux required lots of side band steps due to licensing issues.

[ryao]

ZFS can do multiple copies of a file on a single hard drive. It is not adding parity.

ZFSOnLinux is developed outside Linux’ tree for 2 reasons. One, it is easier that way and two, Linus does not want it in the main tree. Consequently, you need to install it in addition to the kernel as if it were entirely userspace software. That does not add anymore difficulty than say, installing Google Chrome. :/