On Mon, Dec 02, 2013 at 02:56:12PM -0200, Carlos Maiolino wrote: > Hi guys, > > Lukas told me that some guys here might be interested in a talk I did at LPC > 2013 about XFS using dm-thin module. > > For those interested, the slides can be downloaded here: > http://people.redhat.com/~cmaiolin/talks/XFS-dmthin.pdf Hi Carlos, Thanks for sending these slides. They are very interesting indeed. Lukas mentioned that you had run some tests using ext4 and it didn't do well at all using dm-thin? Given that we're not doing proper raid strip alignment in our allocation decisions, that's not too surprising, but it would be useful if there are other things that we should do in order to do a better job working with dm-thin drives. One other question --- in your conclusion you say: Bypassing block zeroing while provisioning blocks adds a significant boost to the dm-thin performance, but, it can induce a security breach, at the risk of exposing stale data This might be true if you are directly giving dm-thin volumes to mutually suspicious VM's with different trust boundaries. But if you trust the file system, and the dm-thin devices are mediated by the a file system running in the same context as the dm-thin volumes, there wouldn't be any security issue, correct? Cheers, - 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
