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October 22 through October 28, 2001

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Go read Brian and Tom's Linux Book NOW!

Email Brian Bilbrey.

Email Brian Bilbrey


Orb Grafitti is sometimes a conversation, sometimes a soapbox. I use Linux most often, and I write about that and related software frequently. I also have a day job working as a dogsbody for a small manufacturing firm here in the SF Bay Area. Tom Syroid and I have co-authored a Linux Book. We're posting it online, here and here. Have a looksee! I'm glad you've come to visit, and always happy to hear from you.

EMAIL - I publish email sometimes. If you send me an email and you want privacy or anonymity, please say so, I'll pay attention to your wishes.


MONDAY    Tues    Wed    Thu    Fri    Sat    Sun   
October 22, 2001 -    Updates at 0721

Good morning... Gosh, is it that time of the year, already? As far as months go, we're in, like, the Friday of the year already. Unfortunately, years don't come with year-ends sized equivalently - I could do with 6 weeks off, I just can't do without any pay at all. This is especially true as we head into the spending season - oh, I mean the holidays. Sorry. I feel like Norm Abrahms (from the New Yankee Workshop) - I can also tell it's finally Fall because yesterday I was the ONLY guy wearing shorts at Costco, and today I have even dug into the flannel side (thus the Norm reference) of my meagre shirt collection.

The good news from the weekend is that finally I was successful in rebuilding Marcia's machine, and getting most of her software setup in place properly. We still have some kinks to shake out, but it's getting there. Overall she's pleased with the performance of the new hardware.

Now, I am running late, so I'd best join the commute. Y'all have a lovely day, and I'll rejoin you later.

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Mon    TUESDAY    Wed    Thu    Fri    Sat    Sun   
October 23, 2001 -    Updates at 0701

Or not... Mmmmm. I got a number of things done last night, but returning to these pages just didn't happen somehow. I don't think I mentioned that I rebuilt Garcia (the main workstation around these parts) a couple of times over the weekend. I've been suspicious of the reliability of this machine with Debian Sid (unstable) layered over the top of Progeny Debian. Additionally, I really wanted to get to running ReiserFS. Finally, I read something that made a lot of sense to me, but I'll need to set this up for you.

In this month's Linux Journal, there's an article about building the Ultimate Linux Box, courtesy of Eric Raymond with Rick Moen. As they were configuring the system, my eye caught on this sentence (in a sidebar that the article attributes to Don Marti):

...and kernel hacker Andre Hedrick says that if you want maximum performance, don't partition any disk. the kernel's "elevator" algorithm for ordering reads and writes doesn't handle partitions well.

If you have one partition spanning cylinders 1-500 and one spanning 501 and up, and one process writes to cylinders 1, 2 and 3, while a second writes to 501, 502 and 503, the kernel will write them 1, 501, 2, 502, 3, 503 - in logical order instead of physical order, which is sub-optimal.

Now isn't that interesting? It's tidbits like this that keep me subscribed to Linux Journal - I'd recommend it if you work with or play with Linux. So I've scrapped my "you are now in a maze of tiny little partitions, all different" setup for a simple two partition setup. Well, four, really. On the two drives, each has one swap partition the size of physical RAM, and then on drive hdb lives the root partition, while home is on hda. Check this out:


bilbrey@garcia:~$ mount
/dev/hdb2 on / type reiserfs (rw,notail)
proc on /proc type proc (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/hda3 on /home type reiserfs (rw,notail)

bilbrey@garcia:~$ df
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hdb2             19438016   2584804  16853212  14% /
/dev/hda3             32731432   5580104  27151328  18% /home

In addition, I am back to using the 2.4.12 kernel, with the latest Alan Cox patches, and Robert Love's Preemptible Kernel patch as well. This is finely tuned. Now if I can just keep from screwing it up by mucking about with it too much. Not bloody likely but worth a shot. I've got just about everything configured right, all that's left is the printer to setup again. Then I'm back to exploring the intricacies of PHP and a CRM product called Relata. So TTFN...

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October 24, 2001 -    Updates at 0703

Good morning. Mmmm, only 32 emails since last night - what have I done wrong? Hehheh. Not too bad, some interesting bits here and there. The official contact between Agenda Computing and it's development community appears to have suffered from a severe dose of Mushroom Management - I have some thoughts on that, but want to let them gel, then probably post first the agenda-users list.

And now for something completely different... email:

Backup Strategies and Linux
From: Jonathan Hassell <hassell@hasselltech.net>
Date: Tue, 23 Oct 2001 15:13:50 -0400
 
Hi, Brian

I thought I'd pick your brain for a second, if you don't mind.

I've had a shell account on hydras for a long time. ?I've been using it 
primarily as a backup storage facility - I wrote a script that zips up my 
home directory using pkzip and puts it on my workstation's desktop every 
Monday morning. ?I then use SSH's SFTP and send it up.

I recently brought up an e-smith server (or SME Server, or whatever the 
hell it is now) and am looking for an automatic way to zip up crucial 
directories (tar or gzip) and send them to Hydras without involving me 
anytime. ?I assume with your wizardry you've probably already written a 
script to do this, or at least you've got the functions down to a fine 
science. ?Would you mind sharing your expertise?

Thanks, Brian.

Jon

---
Jonathan Hassell
hassell@hasselltech.net
http://www.hasselltech.net

The answer involves rysync, ssh and scripts. The tricky bit is
deciding how to do the ssh-tunnelled rsync. The good thing about
rsync is that it is very efficient at only moving up those parts of
a file that are changed. This even works with large gzipped files.
But there's the ssh key passphrase to worry about. You *could* just use
a low priviledge account and a key-pair without an associated
passphrase, but that's only as secure as your box - and a body's got
to assume hackage.

A quick google search later and I think I see the answer. Keychain.

So. Read these:

http://www-106.ibm.com/developerworks/linux/library/l-keyc.html

http://www-106.ibm.com/developerworks/linux/library/l-keyc2/

Then, using keychain, you can have an ssh-agent process running
that's got your private keys registered, so that cron jobs calling
for ssh key-based authentication *should* work unattended. Looks
like a good thing to try. Here's the keychain homepage:

http://www.gentoo.org/projects/keychain.html

Then, a bit of an oops - read the directions rather than the ibm
site for this bit - you want to source ~/.ssh-agent- - a
direct copy of the example fails, but in a way that lets you know
you're looking at the wrong file. ehheh

So, once keychain is up and running, any cron job that uses ssh or
scp just needs to have this line in it: appropriately modified, of
course:

source ~/.ssh-agent-hostname

That goes below the she-bang line, and above any ssh scp commands.
Just works - I've just now tested it. A brief audit of the script
doesn't show any funny business going on. 

To increase security, change the line in .bash_profile to read:

/usr/bin/keychain --clear --quiet ~/.ssh/id_dsa
source ~/.ssh-agent-garcia > /dev/null

for example. the --clear option wipes out the passphrases AT LOGIN,
so that you have to prove your identity with passphrases at each
login, but then those are preserved UNTIL THE NEXT LOGIN - so that
your cron jobs will happily run. the --quiet I'll add after I've
watched it run a few times.

Ah, right - using rysnc with ssh to back something up. Lets say I
wanted a cron job to copy a directory up to another server every
hour. The script would read like this:

#!/bin/bash
#

# Tap into the running ssh-agent process.
source ~/.ssh-agent-garcia > /dev/null

# Tar up the directory.
tar zcf /home/bilbrey/backups/current.tgz /home/bilbrey/gottasave

# Rsync the file up to the server.
rsync -avzr -e ssh /home/bilbrey/backups/current.tgz \
        mybackupplace.com:backups/.

# End of script.

and then a simple cron job entry like this:

0 * * * * /home/bilbrey/bin/backscript 2>&1 > /dev/null

The trailing bits let me pitch out the output from the script,
again, you can watch it a few times in your email to make sure that
all is well, then add the redirection after you're happy.

HTH.

.brian



On that longish note, I"ll depart for work. See you back here soon.

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Mon    Tues    Wed    THURSDAY    Fri    Sat    Sun   
October 25, 2001 -    Updates at 0701

Good morning. Last night was gobbled up primarily with a bunch of RTFM for MySQL. For those of use less Linux-oriented, RTFM generally stands for Read The Fine Manual, although the word dropped into the 'F' slot can vary. As I am working on evaluating and adapting a PHP front end for a MySQL database that ETS can use for CRM, I figured that I'd best properly understand how to use, maintain and secure the beast. I've made a dent in it, primarily reviewing the chapters in the online manual on table creation, loading, deleting and querying. It's been a long time since I had to do any unmediated SQL (not that I ever did very much), so I am pretty cluefree. The good thing is that cluelessness means effectively no preconceptions to overcome. I knew that I could find something good in that ignorance.

During the first part of today I am going to put on my cape and become Tech Writer Man, then draft straight into the Marketing Communications arena. We have a group of products that are accompanied by some fairly technical datasheets and supporting matter from large customers like Cisco and IBM. What I need to do is condense that down to a lay introduction to the technology, complete with executive summary, glossary, and a primitive cost/benefit analysis. I'll let you know how that goes - I've pencilled in four hours for that.

Another recent Brian snapBilbrey, Texas Ranger, according to RBTDan Bowman was first out the gate in noticing via email the new pictures at the top of this page (also like the one at left). Bob Thompson wasn't far behind, finally noting that he liked the older snap that he termed "Bilbrey, Texas Ranger", as shown at right. The reason for new pictures is that while we were moving, in August, I finally just buzzed my hair down to 1/4 inch. It was too damn hot and I was carrying furniture and boxes like there was no tomorrow. If I didn't take action to cool down a bit, there definitely would have been no tomorrow. This is a comfortable cut, low maintenance, and best of all, no bed-head! I can go outside right after hopping out of bed without frightening small children nor causing Marcia any embarassment. Heh.

Mmmm. I am past time. Gotta roll. See you later.

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Mon    Tues    Wed    Thu    FRIDAY    Sat    Sun   
October 26, 2001 -    Updates at 08:35

Good morning. I had an entire raft of email in my main box this morning, and it was late enough by the time I'd waded through that that I might as well do the commute, then update from work. Among other things, I stumbled across a link to a Tardis site ('specially useful for you Doctor Who fans) at this location . Oddly enough, the most recent update to that site is from September of next year!. How appropriate, somehow...

I spent much of yesterday evening wrestling with Perl, Bottlerocket and the X10 Firecracker controller. Yes, once again I am trying to configure my systems to be self-resetting when connectivity goes all wonky. Well, not the systems - I just don't have any connectivity problems with the Linux boxen. However, the Linksys router and the Speedstream DSL modem both seem to head out to the South Forty for a mouthful of alfalfa every once in a while. A brief power-cycle always perks them right up. The drawback here is that I've managed to hose my Perl installations in the process of trying to get the modules I need loaded up. I mean, how tough is it to use CPAN. Bah! I'll figure it out though, then document it here.

Short post and all, I need to get to work here. Tomorrow is clean up day, and some touchup painting down at my grandmother's house. Sunday my friends Mark and Bonnie are visiting for a short bit. They're out here from Pueblo, Colorado for a week, but there is apparently so much family to see that we are only granted a couple of hours out of their busy schedule. Still, I haven't seen them in years, since their wedding out there. It'll be nice... Ooops. Now, really, back to work with me. See you later.

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October 27, 2001 -    Updates at 1030

Hullo. Odd timing, I know. I was first up, wide awake, at quarter to five this morning. That's an utterly alien time of day, designed by sadists for the purposes of torturing people who have 3 hour long commutes (which some people do, here in California, to be able to afford a house). So, as I was saying, up wide awake for a bit at that unreasonable hour, I heard an unusual water-running kind of noise. That's generally regarded as not a good thing, unless you live on a river, in which case the inverse is true. I poked my head around a bit - it really and truly sounded like the source of the sound was from under the house. That would be very bad, indeed. I was shuffling around trying to locate clothing and a flashlight, when one of those bitty half-watt bulbs lit just above my brow... Could it be? Mmmm. I shuffle over to the front door and look out front. Sprinker system. Yup. Sigh.

The sprinklers in front are configured in three zones. When we moved in here, they were set to fire off at 0400, and 1500, every day, for 1/2 hour in each zone. That's three hours of running water each day, to water a few plants and a rapidly rising quantity of weeds poking up through some badly laid redwood bark. Three hours!!! Um, no, sorry. I quickly reset the timer to run 20 minutes each zone, once every other day, cuting that part of our water bill down by 83%. However, having done so, I forget it's ever running, pretty much, especially at Oh-Dark-Thirty of a Saturday morning. Ah well, at least I don't have to run about in the dark and mud, looking for the main shutoff (though I suppose I'd best find that, and the gas shutoff too, while I am at it. In case of earthquake, that's handy information to have available.

Last night, I laid off the computers for a while. I barbequed some steaks that we wolfed down with some nice baked potatoes. Then we were going to watch a movie. The question: Which one? We have a lot of movies on the shelves, and I didn't want to watch a single one of them... well, maybe the original Grinch Who Stole Christmas, but it's really too early in the year for that, advertising aside. So instead we played a couple of games. Sigh.

Marcia kicked my ass, first in Trivial Pursuit, then in Rummy. BAH! I think it's time we broke out the backgammon board. Why? Well, when we first got together, we played backgammon a few times, before Marcia knew that I played at tournament level in that particular game. Zero wins later, Marcia decided that we weren't going to be playing backgammon anymore.


Apparently Agenda Computing, makers of the Linux-based PDA that I use day in and day out, is going through a spot of trouble. According to one developer who should know, it's a flesh wound, as opposed to something more deadly, but that it wouldn't be a bad idea to have a few mirrors of the servers about just in case there's problems in transition. So I'm using wget to suck down the entire ftp.agendacomputing.com tree, as a just-in-case. Then I can setup a simple cron job to pull any new content down on a regular basis. This way if they go the way of the dodo, there's (hopefully) a variety of fallback sources for the data we've all used to run our mini-boxen.


Shortly, we're off to do some maintenance work at my grandmother's house. She fell last weekend, and cracked a couple of ribs. Mmmm, thanks, she's fine, although in pain and not happy at all about that part. She pressed her emergency button, and the paramedics came to the rescue... through the locked front door. My dad did most of the repair work last Sunday, but now it's time for a bit of painting and such. So Marcia and I are off on that mission shortly - Marcia to keep company for a while, and I to do the drudge work, happily. See you later!

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Mon    Tues    Wed    Thu    Fri    Sat    SUNDAY   
October 28, 2001 -    Updates at 1040

Good morning. Hey - surely you remembered Daylight Savings Time ended (for many in the US, anyway) last night. Marcia is noting that I haven't yet gone around changing all the clocks... Well, all the clocks I care about changed themselves, the computers, that is. Hmmmmm. Anyway, an hour back, as I am sure you know. We've been awake for hours - I've been up since about 0615, puttering about, putting the finishing touches on a few items here and there, upgrading the root disk on my Agenda PDA, re-installing StarOffice Beta6, and so on.

Also, Marcia and I have finished up the cleaning, both because it was time, and because we've got guests coming in today - my friends from Colorado that I mentioned on Friday. Yesterday's work at my grandmother's went fine. But this place continues have plumbing problems - there's roots in the line, and it clogs easily. There's usually a bit of pre-warning, as the toilet starts making a burbling noise, which it's doing now. Sigh.

I guess I'd best get busy contacting the estate agent, and who knows what all else. I'd best find out if the equipment rental place is open, so that I can go get a snake and clear this myself, if need be. Take care, see you later.

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Visit the rest of the DAYNOTES GANG, a collection of bright minds and sharp wits. Really, I don't know why they tolerate me <grin>. My personal inspiration for these pages is Dr. Jerry Pournelle. I am also indebted to Bob Thompson and Tom Syroid for their patience, guidance and feedback. Of course, I am sustained by and beholden to my lovely wife, Marcia. You can find her online too, at http://www.dutchgirl.net/. Thanks for dropping by.

All Content Copyright © 1999-2001 Brian P. Bilbrey.