On Thu, Jun 18, 2015 at 01:41:07PM +0800, Qu Wenruo wrote: > >>> Yes. It's an artefact of the way that mkfs works. If you run a > >>> balance on those chunks, they'll go away. (btrfs balance start > >>> -dusage=0 -musage=0 /mountpoint) > >> > >> Since I had to explain this very same thing to a new btrfs-using friend > >> just yesterday I wondered if it might not make sense for mkfs to issue > >> a general balance after creating the fs? It should be simple enough > >> (just issue the balance ioctl?) and not have any negative side effects. > >> > >> Just doing such a post-mkfs cleanup automatically would certainly > >> reduce the number of times we have to explain the this. :) > >> > >> Any reasons why we couldn't/shouldn't do this? > >> > > Following the same line of thinking, is there any reason we couldn't > > just rewrite mkfs to get rid of this legacy behavior?
The 'single' blockgroups on multidevice filesystem are considered a bug in mkfs, an annoying and long running one. > Compared to the more complex auto balance, rewrite mkfs is a much better > idea. Balance is a workaround besides that it requires mouting. > The original mkfs seems easy for developers, but bad for users. I'd argue that mkfs is primarily for users. -- 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
