I've been testing this patch (as well as the accompanying patch to btrfs-progs).
It seems to save a decent amount of space (maybe 10-20% according to df in my testing, YMMV), but I was also noticing a performance penalty of maybe 5-15%, depending on the application (in my case, I was timing the untar-ing of data to a btrfs partition). I also developed the perception that I was encountering some minor latency issues when heavily using a drive formated for mixed data and metadata (more keyboard and mouse hesitations than normal, difficult stuff to quantify). The main problem I encountered was a btrfs crash when booting with an un-patched kernel, and letting the boot process attempt to mount the drive with mixed data+metadata. I wasn't entirely surprised by this result, but it was unclear from the patch description whether a volume formatted with mixed data+metadata would be incompatible with an un-patched, older kernel. Other than that, it seemed to perform well. I did not encounter any stability issues as long as I was using a patched kernel. -- 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
