on-going issues on overlayfs in Linux kernel

As of 2016-02-11, the following issues are critical known bugs about overlayfs in Linux kernel. (overlayfs) moving a file to a directory that exists only in `upper` and deleting it creates unnecessary whiteout file https://bugzilla.kernel.org/show_bug.cgi?id=109611 solution #1: “ovl: ignore lower entries when checking purity of non-directory entries” solution #2-1: “ovl: Do not leave whiteout during … [Read more…]

making firewall to allow multipath-tcp packets

If a multipath-tcp-capable guest VM cannot communicate to the Internet, try to check the firewall on the host, # iptables -L FORWARD target prot opt source destination REJECT all — anywhere anywhere reject-with icmp-host-prohibited You need to allow packets with multipath TCP (TCP option 30). # iptables -D FORWARD -p all -j REJECT –reject-with icmp-host-prohibited … [Read more…]

Running Linux on Dell XPS 15 9530

It has been multiple weeks since I started running Fedora Linux on a new laptop, Dell XPS 15 9530. General hardware specification of the laptop is introduced on http://www.dell.com/us/business/p/xps-15-9530/pd?oc=&model_id=xps-15-9530&l=en&s=bsd. I wanted to install Fedora 22, removing the pre-installed Windows 10. After installing the distro, several issues popped up. * Wireless interface didn’t work. Chipset is … [Read more…]

What Silicon Valley Can Learn From Seoul

(…) The app was quickly adopted by Korean users as a free alternative to text messaging. Part of its success is due to the fact that KakaoTalk functions like its own version of the Internet within a smartphone: Users don’t have to close the app, ever, to check the news, talk to friends, order dinner … [Read more…]