Nevyn's Blog

BOOTP server

2009-05-10T09:16:00.012+01:00

Setting up a BOOTP / TFTP server sounds tricky, but in reality it is marvellously simple. I used it to install IRIX over the network,on my SGI's.

In this example I shared IRIX 5.3 from my Origin 200 running IRIX 6.5.xx to my Indigo R3000. If you are struggling with SCSI bus reset errors from that old cdrom drive, this is a much simpler route to take.

on the server:

/etc/hosts - not required initially, but lets you address the client by hostname from the server.
/etc/ethers - specify the mac address of the client(s)
```
08:00:69:c0:ff:ee       iris
```
/etc/bootptab - this specifies the hostname, IP, (mac?) and the directory to boot.
```
iris    1  08:00:69:c0:ff:ee  192.168.1.118  /cds/irix53/stand/sash.IP12
```
/etc/inetd.conf - here you enable the bootp and tftpd services. It is advised that you use the -s switch to specify which directory(ies) the user can see, otherwise they will have access to all world readable ones (not so bad on a closed network, still better to specify though).
```
bootp dgram   udp   wait  root    /usr/etc/bootp  bootp
tftp  dgram   udp   wait  guest   /usr/etc/tftpd  tftpd -s /cds/irix53
```

finish with this command: /etc/killall -HUP inetd

on the client

enter the command monitor by selecting option 5, and a quick hinv -v to double check all the hardware is recognised may avoid confusion later on.

setenv netaddr 192.168.1.118
setenv notape 1
boot -f bootp()192.168.1.9:/path/to/diskimage/stand/fx.IP12 --x

now repartition / format the drive as necessary (I had to do this a couple of times, it appeared to keep the old installation the first time, and the second time, the amount of freespace was well below the 2GB capacity, which left me with 2 failed installations, but was successful on the third attempt - hint: during the inst phase, I selected the admin commands and looked for the mkfs option. Even though the miniroot was copied to the drive, I wiped it clean - it recovered from the shock by offering to restart the interrupted distribution.

Right, now you've hopefully got a clean drive - restart and

setenv netaddr 192.168.1.118
setenv notape 1
boot -f bootp()192.168.111.9:/path/to/diskimage/stand/sash.IP12
install -n

for some reasoon, this didnt work too well for me, it kept looking for /dev/tape and I couldnt trick it by setenv tapedevice /path/to/diskimage =(

in this case, just select option 2, install the os.
are you using remote tape [y/n] : n
enter the hostname:directory - 192.168.1.119:/path/to/diskimage/dist

once you have the miniroot, and inst running, you should be able to select additional distributions by setting the 'from' to /path/to/disk2image/dist, as appropriate.

HINTS:
This assumes the server is IP 192.168.1.119, and the client is 192.168.1.118
It also assumes you have copied the IRIX 5.3 disc from /CDROM to /cds/irix53/ on the server.
BOOTP wont work across a router, but if you can NFS mount the files across the router, you could establish a nearby BOOTP server on the local segment.
In order to edit the files, especially on a text console, a quick 'man vi' should help
serial port settings are often 9600-8n1 no flow control, see 'man serial'

LINKS:

securing IRIX (more 6.5.xx specific, but still useful)
http://www.blacksheepnetworks.com/security/resources/IRIX_65.html
http://sgistuff.g-lenerz.de/tips/security.php
http://www.siliconbunny.com/irix-security/

Massive List of Rails Development Tips

2009-05-08T16:44:00.005+01:00

I tried out Ruby on Rails the other day, installing it onto Ubuntu, and the ideas it gave me for improving my coding skills / toolset or just generally improving the way I think about approaching programming projects are amazing. Im glad I found these Ruby on Rails development tips, they break down my learning curve into manageable steps:
Massive List of Rails Development Tips

Note that I got it working by also installing a clean AMP - Apache, MySQL and PHP server, and using Ruby Gems to add RoR support. It is possible to run Ruby without the Apache, the built in WEBrick server runs on port :3000 but you can use both simultaneously.

The cheat sheet graphic comes from https://kaul.inf.fh-brs.de

Installing Ruby on Rails in Ubuntu

Create a blog using Ruby on Rails in 15 steps (+5 more if you want AJAX)
this tutorial is pretty reasonable, but there are a few filename typos, and you will need to checkout the comments to fix the odd errata or two...

Total time to get it all working: 2h40 mins

BlueOnyx linux download torrent

2009-04-30T22:49:00.005+01:00

The official BlueOnyx CD's are now available to download over bit torrent! Each ISO has its' own .torrent file - unless you actually require a specific release, you should just stick to downloading the latest one. Each of the ISOs are about 600MB.

BlueOnyx ISO latest .torrent

hint: you may need to "Save As" the .torrent file to your machine (a 25KB size) and load it into your client manually from your local copy

BlueOnyx-5.3-20090405.iso.torrent
BlueOnyx-5.2-20090318.iso.torrent
BlueOnyx-5.2-20090212.iso.torrent
BlueOnyx-5.2-20090107.iso.torrent
BlueOnyx-5.2-20090102.iso.torrent
BlueOnyx-5.2-20081224.iso.torrent

The files are initially being seeded from the UK, and download speeds may be restrictive at first - hopefully before long, it is anticipated that more seeders will join in, and the response times will improve drastically!

PLEASE be responsible - if your bit torrent client is firewalled, meaning you can only leech and not reseed, please consider just downloading the ISO instead, direct from http://blueonyx.it or a mirror!

Switch to a Linux Terminal Server Project network environment

2009-04-27T12:07:00.010+01:00

Get your old computers working as UNIX terminals! Setup a Linux Terminal Server with LTSP on Ubuntu, and use it from a remote workstation!

Im sick of losing machines, and having to reinstall from scratch, so if all goes well on this project, I will be able to run my blade server without even thinkiing about how to set each one up, beyond configuring each blade to boot from the Lan instead of the local hard drive, and instead concentrate on maintaining just the one central server.

Before you cry Single Point Of Failure - and it is, my comeback is that instead of having to make each server resilient, I only have to harden the one, saving time effort, and computer resources. Backups are essential, so I will have a remote machine rsync essential data on a CRON schedule. I will also improve the resilience of the server itself. This can be accomplished by having a couple of spare ethernet interfaces, a bit of software RAID (mirroring the partitions) and optionally a redundant hot/warm spare or even offline server knocking about will do for my purposes =)

To get an LTSP server running on an existing system running Ubuntu, Kubuntu, Xubuntu (which has an LTSP install option) or even Edubuntu, which sets up LTSP by default, you will need to set up a static Ethernet interface where you will attach the thin clients, install two packages and run a single command.

On the server (it can be a desktop, but for this scenario lets call it the server) configure your static / spare interface for the thin clients to have
the IP 192.168.1.1, then follow the instructions below.

sudo apt-get install ltsp-server-standalone openssh-server

Create your Thin Client environment on the server with.

sudo ltsp-build-client

After that, you will be able to boot your first thin client. Note that
if you want to use another IP than the above, you need to edit the
/etc/ltsp/dhcpd.conf

file to match the IP values and restart the dhcp server. If the IP changes (shame on you for not using IP aliases with IP/MAC address takeover tut tut) after you have done the initial setup, run
sudo ltsp-update-sshkeys

to make the ssh server aware of the change.

nb The ltsp-utils package from universe (for dapper) is for a different ltsp version, installing them together will break, so I gather. Maybe worth avoiding that, unless you have a test machine you can experiment on.

Microsoft surface

2009-04-27T12:05:00.005+01:00

This Microsoft "Surface" video (around May 07) shows the coffee table desktop that they were pioneering, aimed primarily at hotels, catering and other hospitality segments.

Its more than simply a horizontal touch screen desktop, as it can recognise & communicate with the (mobile / data) devices placed on it. Words don't do it justice, so please watch the video.
http://www.popularmechanics.com/technology/industry/4217348.html

Yes, I know, a Microsoft oriented post here *gasp!*.

It only merits mention as an example of how interfaces are changing, that computers are evolving beyond the humble, uh... desktop.

With the motion sensors in the WiiMote, multi-touch and motion sensory devices from Apple, and new style desktops like KDE 4, im sure this is only the tip of a proverbial iceberg.

My prediction for the future is that if Asus ever launch the k-eee-yboard, that will be one gadget I can't resist.

UK NSP's - voip service providers

2009-04-27T11:58:00.004+01:00

If you are looking to implement VoIP on your network, you may want to consider contacting these guys, the Internet Telephony Service Providers Association.

Sure enough, this link is more applicable to a business or office IT & IS staff who are looking at alternatives to the PSTN / PBX, analog phone system, who maybe considering software solutions such as glorified instant messenger applications.

Doesn't seem project-ish enough for this blog, so maybe one day I wil get a SIP compatible phone set and set up an Asterix VoIP server! Until then thats all I have for tonight!

Open source handheld

2009-04-27T11:53:00.004+01:00

Has anyone ever had one of these open source handhelds? They make me think of a PSP with Linux on.

Fujitsu SPARC servers

2009-04-27T11:47:00.005+01:00

If you a meaty Unix Server to run Solaris on have a look at Fujitsu SPARC Unix Servers - enterprise class!!

Of course, It probably wont be long until we are seeing Oracle branded servers...
(I, for one, welcome the new corporate overlords)

Solaris 10 developers edition

2009-04-27T11:46:00.002+01:00

If you want to try OpenSolaris out, download OpenSolaris and see this link about VMware tools for Solaris

old cpu's

2009-04-27T11:37:00.002+01:00

Im still in the middle of restoring an old UNIX computer - for reasons most people cannot comprehend. I mean, what good can an old UNIX terminal be? What could you do with a 33MHz cpu, 96MB of ram, 500MB of hard drive and a full 24bit 3D graphics subsystem (apart from spin polygons and play dogfight long before PCs even knew what 2D graphics were...?)

Well, just to remind ourselves, these are the pc processors which we all thought were really up to date at the time =)

The Red Hill CPU guide
http://redhill.net.au/c/c-4.html

Obtaining, Trying and Installing Linux

2009-04-27T11:29:00.010+01:00

You can purchase Linux CD's from the internet if you have a slow connection, have trouble downloading your fave distro or dont want to mess about burning install CD's yourself.

Buy Linux CD's

Note that buying a CD does not mean that you are supporting that particular distribution, as the proceeds will likely go to the vendor who creates the CDs for their materials and labour. If you want to support a distribution financially, visit their website and look to see if there is a donate / merchandise store link. =)

However, you might want to reconsider downloading the distribution as you will get a more upto date revision, and you may find that some flavours of linux e.g. Ubuntu, Slax and Gentoo for starters allow you to run or install linux from a USB memory stick.

Other flavours may even allow you to download linux via bittorrent, such as BlueOnyx. You may wish to try several flavours before you select a particular one, as for example BlueOnyx is a great Server appliance distribution, but people who want to use linux on a single machine may well find that a Desktop edition is more tailored to their needs, e.g. Ubuntu, Kubuntu, Suse

Geek pr0n

2009-04-27T10:58:00.008+01:00

Ever dismantled something to see what was inside? I used to do it to old stuff, once it had broken, and eventually this got round to being peecees. Given enough faulty peecees, you were sometimes able to cobble a working machine together, and even now, the satisfaction you can get from nurturing ailing systems back to life is great!

This became a hobby, and eventually a business, as more and more people came to me to restore machines cost effectively, identifying the problem and correcting it, whether it be replacing a hardware component, or simply helping them through a reinstall of the OS.

But I came across a horde of people online, who take things to the next level. They /void/ warranties on purpose! now I'm not on about unbox.it - the website where people photograph what comes in the box when you get something new, although it is a bit freaky, but in a way it would be nice if the *manufacturers* did this, so you had an idea when you went to buy something.

Oh no, we are talking about the pure, hardcore geek fetish, thats right, serious geek pr0n. These nutters =) actually spend the money to buy something new - then break it on purpose!!

They take photographs of gadgets like mobile phones, Apple Mac Minis and even the Nintendo Wii disassembled

Seriously guys, c'mon... I can't tell if seeing stuff like that in pieces makes me want to laugh or cry! All I do know is that I want to do my own 0-day disassembly post now! damn you!!
=D

Disk drive partitioning tools

2009-04-27T08:10:00.003+01:00

If you are looking for a modern replacement for PowerQuest's Partition Magic (which I once used religiously from version 3.0 upwards) then checkout gparted.

Screenies on there as well :o)

cisco router http server IOS configuration

2009-04-25T00:33:00.003+01:00

here are the commands that worked on a 3620 IOS, in order:

Would you like to enter the initial configuration dialog? [yes/no]: n
(RETURN)

// enable mode
Router>en

// configure the console to stop those annoying messages while you're typing
Router#conf t
Router(config)#line vty 0 4
Router(config-line)#logging synchronous
Router(config-line)#end
Router#

// configure an ethernet interface
Router#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#int fa0/0
Router(config-if)#ip address 192.168.1.118 255.255.255.0
Router(config-if)#no shut
Router(config-if)#end
Router#

// launch the http server
Router#conf t
Router(config)#ip http server
Router(config)#end
Router#

// and now a little sip of coffee, while we admire our handiwork:
// check our work
Router#sh ip http server all

// view connections as they occur
Router#debug ip http all

// view current config
Router#sh ip int br

// we should perhaps end with a copy running-config startup-config ?

NEED MORE?
In case this doesn't work for you, and you want to see what was happening in the IOS, I will paste the actual transcript - with all the system messages and responses included - in the comments, to avoid littering the post.

OpenSolaris 10 is the future!?

2009-04-20T15:51:00.002+01:00

Vindication was the theme at Sun Microsystems today as the company announced that database giant Oracle would select the Solaris 10 operating system (OS) as its preferred 64-bit development and deployment platform.

With the announcement, Sun and Oracle are expanding their joint customer base in the x64 and UltraSPARC markets.

According to Oracle, Solaris 10 will be used throughout its development organization. It will also release and ship 64-bit versions of all Oracle products on the Solaris OS prior to or simultaneous with the release of products on other operating systems.

The Oracle partnership is one of largest endorsements to date of Solaris 10, which had been open sourced under Sun's CDDL license in June.

more here

Oracle buys Sun

2009-04-20T15:31:00.003+01:00

Well, in a blinding u-turn, it would appear that there was someone willing to pay more for Sun Microsystems than IBM.. a $7.4bn deal from Oracle steals the show.

"Guess what's going to happen to MySQL now then..." =o

Read the story here: oracle buys sun/

UNIX command line tips (intermediate)

2009-04-19T16:35:00.003+01:00

It is often seen that when one is using a system he/she tends to fall into set usage patterns. This leads to development of habit of doing things in improper way. In order to overcome these problems the best way is to carefully pick up good habits that offset them.

The following are the 10 UNIX command-line habits worth picking up -- good habits that helps one break many common usage foibles and makes one more productive at the command line in the process:

One must try to inculcate these 10 good habits.

1. One should make directory trees in a simple filch: It is really quite simple and faster to use the -p option to mkdir and to make all parent directories along with their children in a single command. However the administrators often ignore this option that are even familiar with this. Thus one should keep this point in mind.
2. One should change the path but not the archive: One can use this option in order to make entire complex directory trees, which are great to use inside scripts; not just simple hierarchies.
3. One should combine his/her commands with control operators: One should define complex directory trees with single command only.
4. One should use escape sequences in order to manage inputs, which are long enough.
5. One should group his/her commands together in a list.
6. One should use xargs outside of find.
7. One should quote variables with great caution.
8. One should use backslash for long input.
9. One should match certain fields in output and not just lines.
10. One should know when grep should do the counting and when it should come aside.

Article source

Sun SPARC and Solaris

2009-04-19T12:09:00.003+01:00

Came across this article which describes the likely outcome if IBM buyout Sun, which is that AIX is underdevelped versus Solaris, and will likely lose out in the long run to Solaris, which has a whole plethora of enterprise features (of which ZFS is but one) - not to mention the fact Sun also own Java, OpenOffice, MySQL and so on.

I wonder if they would kill or keep the SPARC line of systems, since Solaris shares the codebase between its x86 and SPARC versions.

I really should fire up openSolaris one day - and give Solaris a more fair examination / appreciation. The temptation to go grab a Sun box off eBay, and slap a copy of Solaris 2.6, 7 or 8 on it was too easy, and I ended up with a whole range of machines from a Sun 3, a couple of Sun 4/330's, SPARCstation IPC/IPX'es right through to a very tidy little Ultra 5. All of which where really woefully underpowered for doing anything much, and the 2x SCSI cdrom install process was painful.

Still I persevered, and found that as a desktop environment, Solaris was really not that exciting, a drab corporate grey with a BBC Micro feel about the interface.. I just hope that the technological features do make Solaris really worth using, because those first few steps were uninspiring for me.

I was impressed by the way the Sun SPARCstations didnt have a reset button - a bold statement, and a prominent feature missing that I had come to depend upon, having been a mainly PC user for so long. (STOP-A takes you out of the OS to the hardware monitor, and unlike PC's, you could go and resume execution!)

The Ultra 5 was a favourite of many users, including me now, so I expanded its capabilities with a Sun PCI CoProII co-processor card, featuring a 733MHz Celeron, 128MB of RAM, USB, audio, VGA, serial and parallel ports! (regularly on eBay) - and bought another so I could expand it to 256MB RAM, filling 2/2 slots.

This drove me potty as the 8 bit colour-map switching sent everything psychadelic when in the sunpci window, so I added a 32bit Raptor gfx card.

I've even seen an Ultra 30 running Ubuntu ports.ubuntu.com/dists/,

I failed woefully at getting BSD onto my SPARCs. Perhaps one day I will have the time to try again, with BSD and OpenSolaris.

http://ezinearticles.com/?IBM-Buying-Out-Sun-What-Will-it-Mean?&id=2118836&opt=print

BeOS 5

2009-04-17T22:21:00.007+01:00

I finally got round to installing BeOS again, the original BeOS 5 Professional Edition. It always made me wonder why the OS Install disk said 'free and shareware' on it, when that was on cd 2. ah well, skipping the floppy and booting straight off the cd, I created 4 primary partions on the hdd in my laptop (having just accidentally erased it all with my BlueOnyx CD (big oops) - ah well thats why I build RAIDs and backup servers...

Back to the point, I created 4 ~ 10GB or so partitions, a partition map scheme which completely failed because Windows XP didnt recognise the FAT partition I made, and I had to erase it and start over - and also Ubuntu took several install attempts, why I wrangled with LVM and encryption. Of course, I realised that I would need some unencrypted space (say ~1GB to be generous) for an ext2|3 /boot partition. But now I had used 4 primaries, and had no space for a swap! Numerous false starts later, I finally got encryption and LVM settled down, a space for / and swap contained within, hurrah!

But then the Ubuntu Server edition rebooted after copying all the files on, and came up with an error about PAE missing from the celeron processor in my HP Pavilion ZE21055EA notebook. Damn! With a sprinkling of Blast!, as the Grub bootloader doesnt recognise anything as being installed on my BeFS partion, i.e. BeOS. So I have a triple boot laptop which only runs Windows XP =(

I might be able to recover when Ubuntu 9:04 comes out - doubt it will recognise BeOS still, but I can always see how the Be boot manager copes afterwards. It was always the best chooser.

BeOS then - now, I would like to carry on following the trends, such as Haiku and yellowdog, but since I have the original, I wanted to revive it, perhaps make a VMware VA image of it one day... I carefully selected to install everything, including the developer tools (yes, it seems to have a c++ compiler, whoopee!) which took it up from 200MB to a staggering 255MB or so. I guess I overcooked the partition size ;-)

Ass usual, it didnt have a graphics driver for my particular chipset, so I had a greyscale desktop instead of colour, but - you know what? I prefer it, its easier on the eyes, less strain. Great if you plan on spending long hours coding or some such. If I can ever boot back into it someday, it might become an environment I spend some quality time in,

Firing up the ol' PoorMan webserver, and creating the obligatory "Hello, world!" index.html page for it felt good. Perhaps I can even make it talk php and mysql one day. If not, I can always use SerialConnect and talk to the SGI Origin 2000 MMSC or a Cisco console port or two. All accompanied by the best ever CPU graph to ever grace a desktop.

What I will finish on is a quick note that I successfully managed to get BeOS to run inside the Bochs x86 emulator, v2.2.6 on an SGI Indigo2 10000 running IRIX 6.5. back in 2006. (Screenshots coming when I retrieve them off the appropriate disk).

BeOS lives! =D

SGI Indido R3000 Elan

2009-04-17T21:44:00.006+01:00

Upgrading an SGI Indigo R3000 - an 18 year old machine - is not without risks: the Magick Smoke already escaped once, forcing me to replace the z-buffer board. However, I have sourced an alternative, and coupled with an extra 3 GE's, should be able to take my XS24-Z up to an Elan. Well that's the plan.

Big thanks to Ian Mapleson, for his help sourcing the parts: http://www.sgidepot.co.uk/sgidepot/

I also have plans on trying to get a newer version of PERL on IRIX 5.3, so I can possibly run Webmin. The guys at work think im crazy. You know, they could have a point. =)

Thank you, Jamie Cameron http://www.webmin.com

watch this space!!

update: 24/04/09 - the parts have been despatched via special delivery! should arrive soon. Who put the idea in my head of getting Mozilla FireFox to run on Irix 5.3, eh, Ian - Who indeed? Damn you, there goes my social life this year. Oh well, no great loss =)

update: 04/05/09 - Finally succeeded in booting the machine, but not able to restore the IRIX 5.3 OS yet, due to SCSI CDROM trouble (SCSI bus reset). I've swapped drives, and cables, to no avail. Was hoping to avoid this grief, but since my last update, I've lost 5 servers. (Its been a tough week). The 13 year old SGI O2 which I was hoping to become the network CD share / mount point decided to blow the PSU with a tremendous explosion, the resulting electrical power surge causing a fair amount of collateral on that circuit.

However, I'm back up and running now, limping along on a spare PC server, and an Octane with a dodgy graphics card - at least one of those should help me get the CDROMs online. I might even get around to installing the upgraded hardware, soon!!

Oh, well... looks like Im going to end up installing a BOOTP server again - so look out for the post on that!

BlueOnyx

2009-02-26T21:19:00.000Z

I have decided to follow the (*) BlueOnyx distribution, as it picks up where BlueQuartz was trailing off. It is no 5106R as opposed to 5100R, and retains the sausalito / cce configuration tools.

Customary to practice, I never try a new system out on a production server, so in this case I opted to install it on a spare HDD in an older laptop while I performed some testing.

Since the machine may become disconnected from the network after the install, making it impossible to reach the familiar '/login' url from another client, I have occaissionally opted to install a basic X environment on BlueQuartz, not good for production performance, but great for doing all in one testing, and development on a stand-alone server, lets say =)

There are some new features in BlueOnyx, so I couldn't wait to tryout my fresh install. The install was great, and you now have the following options for install:

- 20GB LVM partition layout
self - manual partition config
small - 10GB LVM installation layout

It is also possible to run 'linux rescue' ... as I found out:

in order to install X + GNOME on BlueQuartz, I did (as root)

yum update
yum grouplist
yum groupinstall "X Window System" "GNOME Desktop Environment"

this failed in BlueOnyx, something about 'dependancy libxxxx.0.so' so I tried X + KDE instead, which appeared to install successfully. To my horror though, I got the dreaded Kernel Panic on reboot.

The solution for me was to 'boot linux' to enter the rescue mode, and

# cd /mnt/sysimage/etc/selinux
# vi config
edit the line "SELINUX=enforcing" into "SELINUX=permissive", save and
# exit
to reboot into the system. (I suggest you simply edit /etc/selinux/config after installing X, but before rebooting, to spare yourself from having to use the rescue system)

This way, instead of

...
unmounting old /dev
unmounting old /proc
unmounting old /sys
audit(1235663670.224:2): enforcing=1 old_enforcing=0 auid=4294967295 ses=4294967295
Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.
Kernel panic - not syncing: Attempted to kill init!

you get
...
unmounting old /sys
INIT: version 2.86 booting
...

=D

To tweak, or not to tweak? (mysql)

2009-01-29T13:03:00.004Z

Assuming you have a cluster of mysql servers serving your application, and you have configured them to share the load, yada yada, your next step is probably going to be asking 'how can I improve the design of database schema?'

Here are some links which cover that field (may I remind you to backup your database before starting, follow them at your own risk, and you cannot hold me responsible for any resulting issues!)

This one illustrates tweeking a Joomla CMS application on a VPS (shared hosting server):
http://www.joomlaperformance.com/articles/server_related/tweaking_mysql_server_23_16.html

This one discusses the differences between innodb and myisam db engines:
http://worthposting.wordpress.com/2008/06/22/innodb-or-myisam/

This appears to be the command to convert a myisam (the default) table to an innodb one, if you wanted to persue that, but beware the monolithic file may need more proactive maintenance and monitoring (for corruption etc, but not fragmentation issues). Again BACKUP!!

-- "ALTER TABLE foo ENGINE=InnoDB"

This one discusses locking, and mysql transactions - no transactions on myisam though! (hence you might need innodb for that)
http://forums.whirlpool.net.au/forum-replies-archive.cfm/498624.html

There's also the problem of race conditions: two select queries (two mysql sessions, webrowsers etc) return the same row, which the application wants to update. The first to 'accepted, the second to 'rejected' - row or table locking will prevent them from writing the new value at the same time, but what happens if both processes complete in lockstep, first 'accept' ing, then 'reject'ing the same row - if only one possible outcome was acceptable? (in other words, a row cannot be accepted after it has been rejected, and vice versa.) We could prevent accidental overwrites by increasing the criteria of the where clause:

UPDATE `orders`
SET `status`='accepted'
-- the first where clause identifies the row
WHERE `order_id`='".$this->DB->quotestring($order_id)."
-- and the second helps prevent 'logical' data collisions!
AND `status` != 'rejected'';

Lastly, this one illustrates a number of different ways one could design a schema
"including discussions on schema architecture, common data access patterns, and replication/scale-out guidelines" using web 'tagging' as an example.

http://forge.mysql.com/wiki/TagSchema

tmobile usb3g on ubuntu / eee

2009-01-20T08:54:00.006Z

Updated May 2009!
I have been informed that after upgrading the eee to Ubuntu 9.04 the usb 3g stick no longer works. Even after recompiling the drivers against the kernel, and a few other attempts to solve it, it would appear that the USB-serial driver which the stick depended on is no longer in the kernel (can anyone verify?).

Current workaround for me is to stay on Ubuntu 8.10 a little while longer, and hope the manufacturer gets the updated drivers out soon =(

---

Having just recently aquired both an Asus EEE 901 and a t-mobile 530 usb 3g broadband stick, work began on figuring out how to install.

On a stock Ubuntu (8.10) distribution, download and extract the 2 tar.gz files. These contain the v1.6 driver (as opposed to the v1.2 in Ubuntu). The README and other documentation aren't very clear, but this is basically how I did it. They might not work for you, so don't blame me if you end up summonning Cthulhu all over your hard drive, or anything else nasty happens.

I've only put them here so I can download them to my own EEE after I replace Xandros by ethernet (The eee WiFi works, but the Xandros WPA is broken) and obviously, I cant use the usb3g yet.... ;-)

# this disables the old option ZeroCD driver
echo "blacklist option" >> /etc/modprobe.d/blacklist
tar xzfmv hso-1.6.tar.gz
tar xzfmv udev.tar.gz
# now cd into each directory and
make install
reboot

I found that the system can crash if the stick is removed.
These are the files from the CD rom that came with the stick, I shall post the md5sums but they matched those available to download elsewhere, so you might as well use the CD if you have it.

Linux drivers:
hso-1.6.tar.gz: 30.05 KB
udev.tar.gz: 27.19 KB

EEE drivers (for Xandros?) - not required for Ubuntu
hso_connect.sh: 7.14 KB
hso-modules-2.6.21.4-eeepc_1.4-4+5_i386.deb: 30.13 KB
hso-udev_1.4-4_i386.deb: 21.03 KB

Edit: Sorry folks, looks like I'd messed up the urls, I've patched them now! =)

Using the DCMD distributed shell to manage your cluster

2009-01-15T12:42:00.004Z

'dcmd' from sourceforge.net provides a suite of commands that can be used, such as dssh. once you have given it a list of user@hostnames, it will send the same command to each one of your desired servers, and echo the response from each one.

for example, `dssh uptime` would be able to respond with all the uptimes of the linux / unix servers in your network or server farm. You could extend this to monitor for failed services, and attempt to restart them, for example...

This article explains everything:
http://www.samag.com/documents/s=8892/sam0310e/sam0310e.htm

Create a new Samba user profile

2009-01-14T21:27:00.003Z

Just a quick one tonight - how to quickly add a new user profile in (Ubuntu) linux and export their home profile directory as a Samba share. (You need to add them twice, once for linux and once for Samba.)

# useradd -d /home/foo -m foo
# passwd foo
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
# smbpasswd -a foo
New SMB password:
Retype new SMB password:
Added user foo.

a couple of things to note - you could use 'adduser' instead of useradd, but that will prompt you for the users info, which you may find you prefer (if in a non-scripted evironment)

also 'smbpasswd foo' might be required if, after running the command to add a new Samba user, it creates that user with a locked account - this should allow you to set the password and unlock them.

now connect to \\servername\username

Quick troubleshooting steps:
check all spellings in the /etc/samba/smb.conf
check spellings on windows client
read the comments in the smb.conf file! (especially the testparm hint!!)

Of course, I'm assuming you already know how to sudo apt-get install samba, configure your '[homes] directory exports in the smb.conf file, and restart samba '/etc/init.d/samba restart'. If not I got all I needed from:
google books (Hacking Ubuntu
By Neal Krawetz)