I run SSHd on my Android phone. This means I can copy files via wireless SFTP, and back it up with BackupPC. It beats using USB or Dropbox. With Android 4.1 and up (Jelly Bean), the default umask for files has changed from “000” (users/programs can write to nearly any file) to “077” (users/programs can only write to files they own). This is better, but meanwhile many Android programs expect the old behaviour. QuickSSHd (a 99p Android dropbear SSH server) is one of them.
I recently added a few new files (.tar.gz archives) to the ownCloud folder on my desktop PC. The next morning I discovered that my laptop couldn’t sync them. The ownCloud client (Csync) displayed:
Csync processing step propagate failed
Starting the client with “owncloud --logwindow” produced this message:
Tags: owncloud
A few months ago, I moved to Linux Mint 14 “nadia”, which is based on Ubuntu 12.10 “quantal quetzal”. I sometimes see this error after running a commmand with sudo:
rm: cannot remove `/run/user/root/gvfs': Is a directory
This happens because the root user has started a gvfsd daemon, which mounts a virtual filesystem on that directory. The root user should never run GNOME, so it should never need gvfsd. But something in Ubuntu 12.10 starts one sometimes.
Cacti is a wonderful tool, but many of the default graphs are ugly. Worse, the “ucd/net Memory Usage” graph is totally useless. It displays memory which is free, or dedicated to cache or buffers. But it doesn’t display the actual used memory or total. And it uses the wrong base, assuming there are 1000 bytes in a kilobyte of memory. I can’t imagine why this graph template is even included with Cacti by default. So, I set out to make a better one.
Tags: cacti
My friend Soren recently gave me a Super Power Bank, a nifty portable Lithium battery pack with two USB ports for charging devices on the go. The Super Power Bank has a 6600 mAh battery with two USB ports for charging devices; one providing 1.0 A, the other 2.1 A. He asked me a question: do my devices charge faster on the 2.1 A port? Down the rabbit hole I flew.
Tags: android, electronics, science, usb
I recently upgraded to Linux Mint 14 “nadia”, which is based on Ubuntu 12.10. I use dnsmasq as a local DHCP server and DNS resolver for virtual machines. Installing dnsmasq on Linux Mint 14 broke host DNS resolution. The issue is easily reproducible: stop dnsmasq, DNS stops working. Start dnsmasq, and it works again.
Tags: dnsmasq, linuxmint, quantal, ubuntu, virtualbox
In another post, I talked about running Wireshark and other sniffing programs as an unprivileged user. You can do the same with Nmap, but it’s a little more tricky.
WARNING: This is dangerous. The Nmap Scripting Engine (NSE) allows scripts to sniff the network, change firewall roules and interface configuration, or exploit vulnerabilities including on localhost. It’s possible, especially with elevated capabilities, for a clever person to use Nmap and NSE to escalate to full root privileges. If you do not understand these risks, do not do this.
Tags: networking, nmap, security
The Wireshark team has long warned us not to run Wireshark as root. However, since Wireshark 1.4 (between Ubuntu 10.04 and 12.04), they’ve raised the stakes. Wireshark no longer loads all its plugins and protocol dissectors when run by root, and it displays warning messages on the CLI and the GUI:
root@laptop:~# tshark tshark: Lua: Error during loading: [string "/usr/share/wireshark/init.lua"]:45: dofile has been disabled Running as user "root" and group "root". This could be dangerous.
Tags: networking, security, wireshark
I spent part of the last two days solving a fun billing problem (if such a thing exists). We had a voice customer on the wrong rate plan, and had to correct the billing using his call data records (CDRs) in CSV format. I had the correct price list, also in CSV format. Enter Super Python Man!
Tags: python
It’s that time again … Merry Christmas, everyone! We have a special card just for you:
http://www.tolaris.com/xmas/xmas2012.php
(In case you miss it the first time, try reloading or clicking the button.)
Tags: xmas
Recent Comments