Hi I am trying to find a way to determine filesystems that cannot be used as a lowerdir for OverlayFS. Looking at https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt , it states "any supported filesystem" however this does not seem to be the case, (where I tried with vfat as an example). I get overlayfs: filesystem on '/lowerdir' not supported searching for the string in the source, then searching for the function, I get to https://github.com/torvalds/linux/blob/master/fs/overlayfs/util.c#L61 Where I am not 100% sure what it is checking for, but as far as I was able to find, it seems that it is checking with something to do with AutoFS (I think if its a mounted autofs filesystem?), as well as it is a case insensitive file system. I could be wrong however. (it also appears in the past, it didn't support filesystems that had revalidate support, but now it does... Let me know if this is the wrong place for this. Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html