Hello, I'm developing a wrapper block device driver called 'WalB' that provides wrapper block devices to get consistent diff blocks without full-scans of devices using Write-Ahead Logging technology, in order to achieve incremental backup and asynchronous replication. Its source code and documents are available in GitHub: https://github.com/starpos/walb https://github.com/starpos/walb/blob/develop/doc/index.creole You can try it from now. It supports kernel 3.2 to 3.9 and x86_64 architecture currently. WalB achieves small overhead of IO response with: - No persistent indexes. - No undo-logs, just redo-logs. - No block-level fragmentation. I've talked about WalB at LinuxCon Japan 2013. The slides in pdf are here: http://www.slideshare.net/starpos/wal-b-linuxconjapan2013 At the conference, I asked Mr. Ric Wheeler what to do for the module to be merged to the mainline kernel, and he suggested submitting an e-mail ASAP. WalB is provided as a single module currently. It seems not so difficult to create 'drivers/block/walb' directory like DRBD. Is that nice idea? or do you have any comments? Regards, Takashi Hoshino -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html