JWC's Homepage
Hello
I'm JWC, an amateur programmer, web designer, hacker, MIT student, and general electronics enthusiast. This site is a repository for my hardware and software projects.
Latest Blog Post
Setting up Remote Nightly BackupsUnfortunately, my hosting provider had a hardware failure and I lost quite a bit of data (everything got rolled back to an 8/17 backup), so I decided to use dar to take nightly differential backups of my home directory (as well as regular backups of various other dirs and databases).
Here is a simple script to remotely take a differential backup of one target server from another.
http://jwcxz.com/other/backup/servernightly.sh
This script is then run from the target server and can be run as a cron job without any modifications. The only caveat is that since this script is only designed to take differential backups, you need to take a full backup first with:
ssh $butgt "dar -c - -z -m 150 -R $butgtdir -q -K :"`cat $bukey` > `date "+$budir/$bupfx-%y-%m-%d_%H-%M.1.dar"`
from the other server.
All of the action happens on the last two lines (they’re just modifications from the recommendations on dar’s notes page). The first of these lines sets up dar_slave, which handles retrieving data from the reference backup to determine which files have been changed. The second is kind of weird since it has an ssh connection within another, but it just tells the backup server to instruct the target server to start taking backups. The backup is named prefix-year-month-day_hour-minute.1.dar. Typically, the differential backups are only a few megs for my home directory.
News
I’ve switched to RAM Host. If you see this message, then DNS information has propagated. I will leave my existing hosting up for a few days before I replace it with a redirection message (for anyone who still tried to use my old domain to go to my website). The old hosting will go away [...]
For some reason, I’ve been using 1024-bit DSA keys to sign my mail. It generally suggested that keys of at least 2048-bits be used for good security, so I have revoked the three keys I have been using (one for each email address) in favor of a single 3072-bit DSA/ElGamal key, which I will use [...]
Throughout this past semester, I was continually impressed by the benefits of powernapping. However, unfortunately, I’m one of those people who shut off their alarms and go back to sleep all the time. So, my 20-minute powernaps became full nights’ rests. Normally, I wouldn’t mind that, but it made things very difficult when I had [...]
… but you may have already figured that out.
A Day in the Life of an MIT Student 2009
MIT’s yearbook club, Technique, sponsors a fun little event every year called ADITL — “A Day in the Life” (MIT does everything in acronyms and numbers, remember?). Basically, the group invites students to bring their cameras around from 12am Thursday, September 24 to following midnight. The goal: take pictures of the things you typically do [...]