Laurence’s Blog

This seems to be going around t’internet at the moment, so I’m jumping on the band-wagon like the sheep I am:

• Grab the nearest book.
• Open it to page 56.
• Find the fifth sentence.
• Post the text of the sentence in your journal along with these instructions.
• Don’t dig for your favorite book, the cool book, or the intellectual one: pick the CLOSEST.

My result:

The process’s scheduling priorty, which is a number indicating its importance relative to other processes. (Essential System Administration 3rd Ed, Æleen Frisch, O’Reilly, 2002)

Having written nothing on my blog since the 1st of September I feel it’s about time to flex my inability to spell (made worse by the fact that my sister has stolen“borrowed” the dictionary I keep by my computer) again and write something.

Since my last post:

• I have quit my job.
• I have started a new job (“IT Services Specialist”) at Loughborough University, part time.
• I have returned to my job at Startin Tractors for the other half of the week.
• my sister has been moved to a more secure secure ward – she’s now locked up with the likes of mentally ill prisoners.

Still it’s all good.

I only wish I had something interesting to put here, but I can not think of anything so instead I’m just going to provide a link to http://bash.org, to annoy anyone trying to work at this point.

I’ve not posted to my blog since the end of May, so after two-and-a-bit months it’s high time wrote something.

Whilst I’ve not been writing, I’ve also not been checking the comments. Due to the amount of spam, I require all comments to be approved by me before appearing on the site, so appologies to all the people who had comments stuck in moderation.

I’ve now been working in my new job for 2 months and it is generally okay. Windows, VisualStudio (2003) and Sourcesafe are all colluding to slowly drive me insane but for the time being I’m keeping the urge to take a Linux LiveCD into work at bay with healthy doses of Ruby and Debian in the evenings.

The one major cock-up I’ve made at work was a MS-SQL script to delete four rows from a table. Another, related, table had been corrupted and every row had been altered to point to the same (one) record in the first table. I had written a script to delete four faulty record and then fix the data in the associated table. Since I was deleting data I, as I make a point to always do, only used the primary key column of the table I was deleting from to ensure only the specific record which needed deleting was dropped. Unfortunately I was not aware of SQLServers ability to cascade delete record, nor was I aware that this feature was in use of the tabels in question. As a result the related table ended up with nothing in it. Whoops! We are waiting for the backup tape to be sent from Derby to Nottingham in order to restore the data to a point before the script was run. Fortunately all scripts which are run on live database servers have to be peer-reviewed, both for syntactic correctness and that they perform the task intended, before they are run so I have someone to share the blame with. I am, as the script writer, ultimately responsible for this mistake (through my own ignorance) however my colleague who reviewed the script should have been aware of the cascade delete and he did not spot the potential problem either. Nevermind.

For the past week I have also been shadowing another colleague who is left the company yesterday to learn about the systems where he was the only person with any knowledge. Last night hosting services, in their infinite wisdom, decided to move all of the servers involved in these systems from one location to an entirely different part of the country. The one thing that could possibly break everything should have now been performed the very night after the last day of the only person who knew these systems! Go go gadget forward planning.
I have a number of other things to write about, but I have to go to work early today in order to be there should the server move cause any problems. Maybe I’ll find time to write some more tonight (I wouldn’t hold your breath, though).

Last Monday (6th Nov 2006) my server suddenly refused to allow postfix to start. I spent the remainder of Monday, Tuesday, Wedsnesday and some of Thursday trying to fix it to no avail at which point I raised an emergency support ticket with Tektonic (who host the system, it’s one of their VPS plans). By Wednesday this week the problem was resolved and I spent Wednesday evening (pre-LUG) in the Computer Science department uploading the backup I have locally to the server, and then Thursday morning was spent putting the files back in the right place and fixing file permissions.

This morning I checked to see how it was doing. A lack of spam assassin processes using processor time indicated that all of the mail should have been processed, and mutt’s ~700 unread emails would seem to agree that I now have all of the mail from the last week delivered. A quick glance at top, however, showed that of the 35 processes normally running (apache, spamd, cron among others) only 11 were actually running at the moment (fortunately one of the was sshd). Grrr. I restarted the VPS and everything was back to normal, however withing 15minutes 35 processes had again be reduced to 11. The logs indicate that the processes are killed (that is they receive a kill signal, and exit) which is very perculiar as I am certainly not killing them. I restarted for the second time and again things seemed back to normal, however when I pointed a web-browser at my blog it said “wordpress is not installed”. A quick look at mysql showed that one of the tables, “wp_options” had been corrupted and was unreadable by mysql. I again restored this table from backup and my blog seems to be working (more or less) again.
I have never has this VPS working for more than 24hours without processes being killed, apparently randomly. Somethimes it’s just one or two processes, sometimes all of them. Tektonic provide an interface to show if you hit a resource limit (e.g. running out of RAM) but this shows no alerts at all for me. The only time it has ever shown anything is when I ran out of disk space (due to an accident involving dd and a factor of 10), so I can only conclude that it us either broken for memory on my VPS or I’m not hitting any limits and something else is going on. I would, happily, move away from Tectonic if it wern’t for that fact that they are so cheap.

Aside from my email, I’ve also been without my svn repositories on this server which has been a right pain.

It’s been quite a while since I’ve written anything on my blog. To a great extent I’ve just been far too busy (this hasn’t changed, but being back at Uni there is noone watching me from behind to see if I’m not working) and during the holidays I do not get the oportunity to use a computer much outside of work due to a lack of time.

Three important things have happened since my last blog entry;

Firstly, I’ve had surgery on my mouth to remove two of my existing teeth and have implants placed into my jaw which will, when healed in 3 to 6months time will support four false teeth in their place. I am missing a significant number of teeth (which I’ve never had) and the problem seems to be genetic – my mother has a large number of teeth missing as did her father. The ongoing appointments for this are proving quite disruptive and I an ending up missing lectures quite regularly at the moment (co-incidentally the lectures always seem to be for the ‘Compiler Design’ course, dispite me missing them on different days and at different times.

Secondly, The deadline for handing in my third year project specification was last Thurday. While I managed to hand in the required work before the deadline, the work I handed in contained a number of errors which I should have spotted. The main reason for this was that I made a mistake and overwrote the latest version of the specification with an older version which ment I then had to waste a lot of time recovering the newer copy. Had this not happened I would probably have had an extra 3-4hours to spend on getting it right and would not have rushed and handed in an erroneous version.

Finally, Over the holiday I have reached the conclusion that CompSoc, as a group of people, suck. The ideas on which CompSoc is founded, as an academic society who provide support, guest lectures and tutorials for people who like computers are great and like a number of people in CompSoc I simply love computers, however CompSoc is increasingly being taken over by two types of people. One of these is the gaming types, whose sole interest is playing games at every opportunity and are of the opinion that anyone who doesn’t want to play games all the time is not worthy of being in the society. The other group are the type who simply moan all the time about everything. They seem to complain for the sake of complaining and are completely unwilling to do anything productive to fix the problems they moan about.

I for one am sick to the back teeth(well, sick to what back teeth I have) of people moaning and bitching at people needlessly. This is the reason I have left, and do not intend to return to, the #compsoc irc channel on their irc network which is where all of the active members tend to spend their time. Since leaving #compsoc I have noticed no unjustified moaning occuring in any of the other 13 channels I am in on CompSoc’s IRC network. The thing that really gets to me is people bitching non-stop about things which other members have put a significant amount of their time and effort into and get nothing in return. Members have no obligation to take part and do stuff for CompSoc, like the website, the IRC bot, helping manage the servers and setup LANs the least they could expect is not to be bitched at constantly for something they have given time and effort for, entirely volunterially.

There was a suggestion that the Warwick Linux User’s Group could part from CompSoc and form its own society. This idea was quickly shouted down as, among other things, it might spell the end for CompSoc. I’m not sure that this would have been a bad idea. If the LUG had left, at least CompSoc might have been forced to get its arse in gear and stop being the ‘gamers and bitchers’ society.

If it weren’t for my multiple obligations to the society and the fact that I know a grand total of about 0 people outside of CompSoc I would seriously consider having nothing more to do with them. Thankfully the LUG, which has not had any of these issues, is continuing to move in the direction it was 2 years ago with semi-regular tutorials planned and maintaining the social atmosphere of their meetings. Had the LUG left CompSoc, it would have been a much better society than that which CompSoc has become.

hmm, so I installed debian again on my laptop yesterday (instead of doing coursework). The compile-time got to me again. However it[gentoo] is one of the few distro’s which currently have the 2.6.16 kernel, which includes the drivers required for my desktop’s TV card (according to various websites – completely untested by me). Gentoo did well to last a week, most other distro’s aren’t so lucky.

On another note, microlog helpfully embeds smilies within other BBCode blocks, including code blocks (which SimplePHP Blog did too and is simply irritating) and url=$url – this breaks horribly when it replaces some text in $url with a smilie. Nested html tags DO NOT WORK and thus both the url and the text displayed is horribly broken. Oh well, off I go to find another piece of blog software.

Although Simple PHP Blog does it’s job, it has a few irritating quirks. So much so, that one of my suggestions for a third year Computer Science project was to write a database-less Blog script which worked the way I wanted.

While searching for an alternative, using the phrase ‘blog no database’ (since, due to an error on the TechTeam’s part I have no database when I should have a MySQL database) I found Jean-Claude Wipple’s blog. On it he is complaining about programs which do not use databases, which I found quite hipocritical since he’s (coincidentally) using a database-less blog script written in bash, of all things!

This looks very interesting, especially as I’m a fan of bash. Maybe I’ll have a poke and look into replacing this blog with it…

I’ve just finished replacing my old blog software (Simple PHP Blog) with a new one. The new one, Marko’s µBlog, is a lot nicer and more easily customisable so hopefully I can hack it into behaving as I expect.

I’m going to leave the old blog up for another hour or so, so I can have a go at hacking the new one’s CSS and also give the people who subscribed to my blog’s RSS feed( if there are any) a chance to be told of the impending change.

Here’s some random URLs I thought might be interesting:

Browse Happy
A website explaining why Internet Explorer is unsafe for use on the web. Unlike most other websites of its kind it is not favoring any particular ‘alternative’(read: broadly safe) browser, but instead provides a list of alternatives and a possitive description of each.

sorttable: Make all your tables sortable
This site has a nifty looking piece of Java script which instantly allows any table on the web-page to be sorted by any column by defining it to be of the class ’sortable’. Since this is Java-script the sorting is done client-side so no need to resubmit the page for re-ordering nor will it whore over the server its running on with lots of needless(at least as far as serving web-pages is concerned) sorts.

apt-get.org: Unofficial APT repositories
A place to share usefull (Unofficial) repositories for Debian.

Simple PHP Blog
The software my original Blog was using – no SQL needed, it’s all stored as text files. Easy to configure and update – just decompress and go. Fantastic! My only gripe is that most of the themes are fixed-width, and the only non fixed-width theme is not configurable wrt colours. Creating themes doesn’t appear to be very straight forward either, unfortunately. Maybe I’ll have to write my own blog software which only uses CSS for theming, so creating a new theme simply means modifying a CSS file… hmm, yet another project I’ll probably never finish.

I recently (re-)discovered I’d actually installed a blog script, and never written anything down! Oh well, no time like the present to start – I wonder how long I will be able to keep writing entries before I:

1. get bored with the whole ‘blog’ idea
2. simply forget about or neglect the blog to the point that it disappears from my mind (again!)
3. I get distracted by some project or other.

I recently managed to set up a Debian-based mail server. I originally searched google and came up with a number of guides to doing this which looked quite good, albeit long but it’s a project I’ve been planning for a while so I decided to bite the bullet and have a go. After installing Debian and playing around with various different approaches for a bit, I discovered an entry on another blog at The Tech Terminal explaining how the author had setup a Debian Mail Server. This simply said that all I had to do was enter this:

# apt-get install courier-imap
# apt-get install postfix
# postconf -e 'home_mailbox = Maildir/'
# postconf -e 'mailbox_command ='
# /etc/init.d/postfix restart

at the command line. This was certainly a lot easier that the 8-page guide I had be following previously, and it worked .

Using other guides to install spamassassin and squirrelmail and it was all working very nicely. Fetchmail and gotmail were easy to install and configure using the man pages so I didn’t need to enlist google’s help with them. I now have a single server with 2×40GB HDDs (configured for RAID 1 using a PCI PATA RAID card) which goes and fetches emails from my 2 POP accounts and my hotmail account and delivers them to my local user on the machine (for my purposes I decided LDAP was overkill and that dropping the mail to a local user’s Maildir made more sense). This means I can now access my mail using an IMAP client on either my desktop or laptop, or I can use a web-browser from any other location.

One small snag did run into is that Maildir creates a directory for each directory on the server (as you’d expect) but doesn’t nest them. I was expecting them to nest and it took a while (and some head-banging) for me to discover that Maildir actually uses a ‘.’ to represent sub-directories.
e.g. this structure:

Inbox
:-New
:-Badgers
: :-Mushroom
: :-Snake
:-Llama

becomes this Maildir structure:

/Inbox
/Inbox.New
/Inbox.Badgers
/Inbox.Badgers.Mushroom
/Inbox.Badgers.Snake
/Inbox.Llama