On Sun, Jan 22, 2012 at 11:31:31AM +0800, Robin Dong wrote: > > At the end of the day, thinp target is a very powerful tool, but > > is does not fit all use cases. In particular, it fragments the > > on-disk layout of ext4 metadata and benchmark results for how this > > affect performance were never published. Amir, Well, to be fair, your approach to snapshotting also causes fragmentation. If a file or a directory in the base image gets modified while there is a read-only snapshot, the inode in the base image gets fragmented as a result. It is true that thin provisioning in general tends to defeat the block placement algorithms used by a file system, but it will be possible to create snapshots of non-thinp volumes, which will address this issue. Hopefully in the next 3-6 months, these things will be implemented enough so that we can benchmark them and see for certain how well or poorly this approach will work out. I'm sure there will be a certain number of tradeoffs for both approaches. Regards, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
