There is a home server with raid 6 sitovym configured using mdadm.
The problem is that sometimes some files become zero-length, and sometimes some files disappear. But, the thing is that I don't know that for sure, never been able to catch a RAID on what the file was and then isschezli, or that he was originally a size, and then disappeared. Perhaps the file was originally a zero-length, or absent.
How can I verify the integrity of the RAID to identify problems, to recover lost files, restore corrupted files?
Linux home-server 4.4.0-103-generic #126-Ubuntu SMP Mon Dec 4 16:23:28 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux