Eastern Vacation Journal, Sunday, July 15

Tuesday, July 17th, 2007

The route for day 2 took us into the Great Smoky Mountain National Park. I'd decided, like a typical male, that if we were going to see one thing, we should go to the highest point. This turned out to be a good call, as it's one of the most notable points in the park: Clingman's Dome..
There's a nice parking lot at the bottom of about a half mile paved path, leading to the most curious structure I've ever seen in a national park.

I'm still not exactly sure how I feel about it — it's as if the park service was taking design cues from Disney's Tomorrowland. You will not be shocked to find that this was, in fact, designed and built in the 1960's. Pretty much everywhere else I've traveled, an effort has been made to keep things natural, perhaps inspired by Native American Culture. This, however, is a pure work of abstract art in concrete. It does have a kind of sparse elegance, and it's really impossible to see until you're right on it, so does not form much of an eyesore.

Overall, the Smokies were a bit sad. The texture of the place is gorgeous — green, shady hollows, beautiful mossy rocks, and the day we were there it felt as if we had the place to ourselves. However, the sweeping views are no more (at least not very often) due to increased pollution. The hills used to be draped in a natural ethereal mist — now, as you look off the peaks, it just fades into blank whiteness after a few hundred yards. Views notwithstanding, it is a beautiful place “up close”.

One highlight for me was getting to walk a few steps on the Appalachian Trail. At least some of my route planning on this trip was inspired by Bill Bryson's A Walk in the Woods — a funny, touching, and informative tale that inspired me to strap back on my hiking boots after a 10 year hiatus. I'll never hike it — if I ever do a large-scale “through hike” it'll be the Pacific Crest Trail. It was nice to be able to see it, and get a sense for what it would be like to hike it.

Our next real stop was another section of the “AT” — Skyline Drive in Shenandoah National Park. However, before we could get there, we had to leave. The ever-helpful GPS (seriously, a fantastic device, I'll probably write a whole article on it) directed us out of the park and through the complete mind-trip that is Pigeon Forge, TN.

Imagine the Las Vegas Strip — that many cars, that much traffic, that kind of vibe going on up and down each side of the street. Now take the hotels and turn them way, way down — Days Inn style. Now take every carnival you've ever seen, blow it up 10 times bigger, and sprinkle it down the street. It's insanity — Mini Golf course after Mini Golf course, 35 lasertags, several of these 5-story-high go cart courses that look straight out of Mario Kart, store after store selling worthless low-priced crap, and let's not forget (I am not making this up) Dollywood.
Some moments worth capturing from the car:


45 types? Really?


Kids today with their “internet”. I'm a sucker for “useless” “use” of “quotes”.


You may feel bad for having seen this, but at least I didn't shoot video. The jiggle factor really made this moment special.

I realize that I sound like some kind of insufferable LA snob in writing all of this, but it's very hard not to. I've determined that I'm not a racist in the slightest, but I am pretty clearly a “culturist” in some form. I can find things to respect and appreciate from pretty much any culture, but man do I struggle with whatever this one is. (Redneck, perhaps?)

Anyway, enough with the semi-negativity. Once we made it out of the Pigeon Forge Traffic Jam, we whisked ourselves North and West to Shenandoah. Skyline Drive is a pretty amazing experience. It's over 100 miles long, and runs basically along the top of a mountain ridge, so there are great views to both the left and the right. We got out of our cars a few times to stretch our legs and enjoy the view, and did a few miles of hiking as well. The wildlife sightings were fantastic!


We saw this lovely deer ahead of us on the trail. It was certainly concerned about us, but it didn't make a break and run for it. It did the “deer tiptoe” around us through the brush. We saw (and managed to photograph) several more deer as we were driving.

The most exciting moment I'll have to simulate, as we weren't able to get a good shot. (According to flickr, this was taken within 3 miles of our sighting anyway:)

It's been a long time since I'd seen a bear in person and up close. We were driving through a little valley-shaped section, and he came barreling down the hill behind us, crossed the road, and up the hill on the other side. Awesome.

We finished the day (having driven about 80% of Skyline Drive) by heading down to Luray, VA. We had a great dinner at a local place called “Uncle Buck's” — we forgot to ask if it was named after the John Candy film or not. I have to remember that in Rural America 9PM is a weird time to be looking for food, we had to try 4 places before we found this one to be open. Amber and I shared a half chicken with sides for a whopping $7.99. NICE.

Thus closed another day on the road. Next up, the Caverns of Luray and the fascinating city of Baltimore.

Eastern Vacation Journal, Saturday, July 14

Monday, July 16th, 2007

We head to the airport. Note to self — you get what you pay for. We found cheap tickets through AirTran and, apparently, so did everyone else. Airtran Logo They had 2 gate agents, one of whom was busy with one annoying girl the entire time we were there — and a line stretching pretty much the entire length of the terminal. We made it aboard, but were not comforted when, waiting to actually get on the plane, a young lady got off, escorted by a flight attendant, as “my seat and my whole row just fell apart.” In any case, the flight was otherwise uneventful. Arriving in Atlanta we could see why it was popular — LA must be an incidental destination for them. They pretty much owned the whole concourse over there.

The rental car was an interesting situation — turns out, at some airports, National only has “compact” cars, even though they advertise “economy” and “compact.” Since we're driving so much, and there's only the 2 of us, I was saying “tinier is better” and signed up for the economy. I was expecting a dinky Chevy Aveo — and got this lovely beast instead. (In other words, you get a compact for the economy price, since they don't technically “have” any economy cars.) While yellow is not my first choice in car color, it's fun to drive, has XM, a line-in input for the ipod, a sunroof, and gets 32MPG. I was very pleasantly surprised when my first fillup was $30.

Ah yes, as you can see, our first meal was at the Waffle House, apparently an institution around here — you see the signs at pretty much every off ramp. I'd seen them when I was in Georgia for my brother's wedding, and we didn't get a chance to sample. We're all about absorbing the local culture on this trip, so we gave it a shot. It was tasty food, no doubt! They do make a very good hash brown.

First stop: Maggie Valley, NC

Our first real destination was the Great Smoky Mountains National Part , so Maggie Valley was a good nearby spot to get a hotel. It seemed to be a kind of family vacation kind of place — the smokies seem to be entirely filled with hotels, mini golf, and more hotels. Chillin on the porch with the rockers Notably, Best Westerns appear to have really top quality wireless internet for free. I found this amusing since the 2 of the last 3 hotels I've stayed in (a) cost 3 times as much as this and (b) charged $10 for mediocre wifi.

As it happens, Amber and I are both fans of the mini golf, so we walked down the street and took in a game. (Had we felt like it, we could have visited 3 more such facilities in less than a mile.)

The surroundings are incredible in that part of the country for a native Californian. From the minute we got in our car, even driving close to downtown Atlanta, the whole world was GREEN in a way that's pretty foreign to us. Even in our national parks, things tend to be green in kind of a scrubby, piney kind of way. Here there are large, broad-leaved, lush looking trees growing on top of other broad-leaved, lush looking trees and the whole thing appears to be covered in some kind of ivy, just in case there weren't enough broad green leaves to go around.

So, travel-weary, we brought our first day to a close, readying ourselves for the driving and scenery that tomorrow would bring.

Migrating live filesystems to LVM

Tuesday, April 4th, 2006

These days, we build all of our new (linux) hosts with LVM. This is great since it allows us to quickly bring in new storage in a given file system, be it local or network attached. It also allows a nice graceful way to 'hop' a given volume from one storage device to another — you simply add the new device, then use 'pvmove' to move the blocks (while the file system is 'live') from one device to the other, then you remove the old device, and you're done. All with nary a blip as far as the noble users of the system are concerned.

The tricky thing is when you need to do the same thing — and the host you're working on is a regular old block device formatted with ext3. What to do? It's important not to have downtime. This is a big filesystem with lots and lots of data, and even more nastily, lots and lots of hard links. It takes something like rsync 3 hours just to start up, let alone start copying data.

The trick came as a flash of insight to one of my esteemed colleagues. Linux has a wonderful software raid facility. In mirror ('raid 1') mode, it synchronizes 2 block devices. It doesn't care what filesystem (if any) they are running. It doesn't care if they're real devices or other 'synthetic' block devices like LVM. And when they're in sync, you have 2 block devices that are both identical and 'normal'. If you reboot and mount either of the members of the raid, they have full, 'normal' filesystems on them.

So the technique becomes so simple it's almost self-evident.
0) BACKUP BACKUP BACKUP
1) Create your new (LVM'd, if that's what you wanted) storage
2) Create, with mdadm, a raid 1 where the primary disk is your existing filesystem.
3) Remount your mount point using your new md device
4) Watch /proc/mdstat as your drives magically synchronize, staying accessible and live all the while.
5) Unmount the /dev/md* device, remount your shiny new filesystem, and go away, happy as a clam.

It really illustrates the power of abstracted block devices. We went to a talk given by an engineer from Google who was talking about the future of commodity storage at Google — they're looking at building clustered storage which, at the back end, consists of block devices bolted together with
ddraid and some similar but seemingly yet unpublished tools. It's a cool time to be getting to play with computers for a living.