Daily Archives: March 11, 2010

All things Unix, Webcraft

Backups Matter

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Having been a Unix systems administrator for about 20 years and “in the IT business” for more than twice that time, I have always been aware that that tedious task of backing up your data can pay off in the end.  As we say, there are two types of computer users:  those who have lost valuable data and those who will lose valuable data.  But, backups can help.

The other day, while between crises at Chaos Central, our home/office/workshop, I was browsing through the web statistics for our public sites and actually paid attention to the list of ‘404’ (File Not Found) errors.  Now, a lot of these are the usual and customary web site attacks that go on all the time, “bad guys” probing for security holes that a) don’t exist because we are not using Microsoft Internet Information Server, or b) have long since been plugged in Apache, so I more or less ignore those, along with the blind probes for informational pages to gather email data to feed SPAMmer’s address lists.  But, since I have been using Google’s Webmaster Tools to aid in Search Engine Optimization (SEO) for my clients,  I’ve paid a bit more attention to little things, like having a ‘robots.txt’ file even if I don’t have any pages I want to hide from the search spiders.  Another one is the ‘favicon.ico’ file:  you don’t need one, but browsers always ask, so it is nice to have one.  Besides, it adds a distinctive icon to the address bar, tab, or ‘favorites’ list, so I have been creating those tiny graphics and adding them to sites as well.

But, this time, I also noticed missing pages where there shouldn’t have been any.  Oh-oh.  Until sometime last year, we had a number of links from our public server pages to our ‘extranet’ server located in our home office and port-mapped to our external router.   Some issues with our Internet service at home and our impending move made it imperative to move these pages onto our public servers, which I more or less did, in bulk, to a virtual server, and changed all the links to point to the new location.  I had thought I had tested all of the links, but here we were, many months after the transition, with a broken link.  An entire page and all of its images, gone.

Meanwhile, the old extranet computer had not survived the household move.  After sitting in a cold, damp basement for a month or so last fall, it refused to start.  But, we still have the last set of backups!  So, I extracted the files from the backup archive and uploaded them to the web site.

For the record, we are, of course, a Unix shop, running mostly Solaris and Linux, so we use Amanda, the open-source backup system from the University of Maryland, and backup to virtual tape on cheap USB drives.  The drives are large enough to keep several weeks’ worth of backups, and we archive the last backup set from “retired” machines.  For machines like my Linux laptop, that aren’t necessarily on or even in the network 100% of the time, I use rsync, freezing a checkpoint now and then, since we do upgrade Ubuntu versions, and we keep a pre-upgrade backup as well as current ones.  Because the Amanda backup runs daily, but we do a lot of work during the day, we also keep a snapshot backup (using rsync) every couple of hours during the workday on our main server/workstation.  For our one seldom-used physical Windows machine, we simply copy our working directories onto a file share on one of the Unix systems.

So, there are many ways to do backups, but it is important to do at least one of them, whether or not it seems to be a pain–it will pay off.  Oh, yes, I am in the group of users who have lost data–in my case,  I archived data, then failed to make a second copy before the orginal archive failed.  And, just because I’ve lost data once, doesn’t mean I won’t again, backups or no backups.  But, keeping good and current backups does reduce the chances that it will be soon or extensive.

Bicycling, Travel

Parking Meters are Evil

Yesterday, my tandem bike stoker (and life partner of the past 25 years) and I headed to the Big City by automobile to  run a few errands and check out the bike-path/walking trails around Capitol Lake.

Since the day had started cold and threatened to turn wet, we parked at metered parking on the downtown side of the lake, rather than out on the parkway on the far side of the lake.  Standing in the cold breeze from the lake and looking at the rain-laden clouds sweeping in from the Coast, and, with the closed-for-repairs causeway less than 500 meters down the shore, I thumbed enough of our dwindling supply of nickels into the meter for what seemed to be a generous 40 minutes of brisk walking.

As we  moved into the lee side of the hill on which Washington’s Capitol campus sits, the wind didn’t seem so cold, and we noted a switchback trail leading to the Capitol, so we diverted.  In the 30 years since I first came to Washington State,  I had never been to the Capitol itself, so it seemed like a good idea at the time to check it out.  After reaching the top and strolling past the domed seat of government, we noted that we only had eight minutes to get back to the car before the meter expired.

It wasn’t far as the raven flies, but ravens don’t walk down switchbacks, and the eight minutes expired by the time we reached the lake shore, where we noted, in the distance, the flashing red light of the  Parking Enforcement vehicle as it moved down the street–away from our car.  One more nickel would have saved us:  the time stamp on the $15.00 parking infraction was three minutes after the meter expired.  Officer Lisa must have sat in front of the car waiting for the LCD to flash all zips.  The car next to us also had a ticket, so it was obviously a good place to just hang out and watch the meters tick.

Needless to say, the afternoon gloom intensified inside the car as well as out on the drive home.   Parking meters are evil: you can’t add more time unless you are physically there, and they don’t record how long the meter has been expired, or know if the same car has been in the spot for more than the 3-hour limit.  In some municipalities, the parking enforcement folks make more than one pass to check for deliberate violators.  Obviously, there is no “grace period” in Olympia, especially during the legislative session when parking space is at a premium.

So, the moral of this story is:  be generous with your supply of nickels at the meter–if you return on time, pass your good fortune on to the next car, or consider it a tip to the city for having a convenient spot for you to have parked in.  Or, bring your bike and park the car in a free lot outside the city core.  Next time, we will.