Hi folks, I have been working on an incremental backup tools of thin volumes created by dm-thin for a couple of months. This tool relies on the data mappings dumped by thin_dump from the thin-provisioing-tools. As I update thin_dump from version 0.1.5 to 0.2.7, it cannot work correctly as the earlier 0.1.5 version. The following things have been observed: 1. thin_dump-0.2.7 cannot take user-specified "metadata_snap" as v0.1.5. It will always return "bad checksum in superblock". 2. If "metadata_snap" is not given by users, thin_dump-0.2.7 only dumps the out-dated data mappings which can be recognized by observing the wrong "transaction id". Since it looked like thin_dump failed to get the most up-to-date metadata blocks in version 0.2.7, I dig a little deeper into the source code and find something that might cause the problem. The open flag used on metadata device has been changed from "O_DIRECT | O_SYNC" to "0" in commit 4deb1751a650010ce9c15910a064be1348dec8ba . After I changed this back to "O_DIRECT | O_SYNC" in version 0.2.7, it works as expected once again. So here is my question. Can I change this flag back to "O_DIRECT | O_SYNC" in any newer version? I am worry about that I might accidentally mess something up by changing this flag. Also, what's the purpose to get rid of the "O_DIRECT" and "O_SYNC" flags when we migrate to version 0.2.x? Any help would be highly appreciated. Best Regards, Dennis -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
