Robert White posted on Fri, 24 Oct 2014 19:41:32 -0700 as excerpted: > On 10/24/2014 04:49 AM, Marc MERLIN wrote: >> On Thu, Oct 23, 2014 at 06:04:43PM -0500, Larkin Lowrey wrote: >>> I have a 240GB VirtualBox vdi image that is showing heavy >>> fragmentation (filefrag). The file was created in a dir that was >>> chattr +C'd, the file was created via fallocate and the contents of >>> the orignal image were copied into the file via dd. I verified that >>> the image was +C. >> To be honest, I have the same problem, and it's vexing: > > If I understand correctly, when you take a snapshot the file goes into > what I call "1COW" mode.
Yes, but the OP said he hadn't snapshotted since creating the file, and MM's a regular that actually wrote much of the wiki documentation on raid56 modes, so he better know about the snapshotting problem too. So that can't be it. There's apparently a bug in some recent code, and it's not honoring the NOCOW even in normal operation, when it should be. (FWIW I'm not running any VMs or large DBs here, so don't have nocow set on anything and can and do use autodefrag on all my btrfs. So I can't say one way or the other, personally.) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
