Tag Archive for Linux Distro

Sorting out MySQL on Arch Linux

November 5, 2011 No comments

Seeing Arch Linux running so solidly in a VirtualBox virtual box has me contemplating whether I should have it installed on a real PC. Saying that, recent announcements regarding the implementation of GNOME 3 in Linux Mint have caught my interest even if the idea of using a rolling distribution as my main home operating system still has a lot of appeal for me. Having an upheaval come my way every six months when a new version of Linux Mint is released is the main cause of that.

While remaining undecided, I continue to evaluate the idea of Arch Linux acting as my main OS for day-to-day home computing. Towards that end, I have set up a working web server instance on there using the usual combination of Apache, Perl, PHP and MySQL. Of these, it was MySQL that went the least smoothly of all because the daemon wouldn’t start for me.

It was then that I started to turn to Google for inspiration and a range of actions resulted that combined to give the result that I wanted. One problem was a lack of disk space caused by months of software upgrades. Since tools like it in other Linux distros allow you to clear some disk space of obsolete installation files, I decided to see if it was possible to do the same with pacman, the Arch Linux command line package manager. The following command, executed as root, cleared about 2 GB of cruft for me:

pacman -Sc

The S in the switch tells pacman to perform package database synchronization while the c instructs it to clear its cache of obsolete packages. In fact, using the following command as root every time an update is performed both updates software and removes redundant or outmoded packages:

pacman -Syuc

So I don’t forget the needful housekeeping, this will be what I use in future with the y being the switch for a refresh and the u triggering a system upgrade. It’s nice to have everything happen together without too much effort.

To do the required debugging that led me to the above along with other things, I issued the following command:

mysqld_safe –datadir=/var/lib/mysql/ &

This starts up the MySQL daemon in safe mode if all is working properly and it wasn’t in my case. Nevertheless, it creates a useful log file called myhost.err in /var/lib/mysql/. This gave me the messages that allowed the debugging of what was happening. It led me to installing net-tools and inettools using pacman; it was the latter of these that put hostname on my system and got the MySQL server startup a little further along. Other actions included unlocking the ibdata1 data file and removing the ib_logfile0 and ib_logfile1 files so as to gain something of a clean sheet. The kill command was used to shut down any lingering mysqld sessions too. To ensure that the ibdata1 file was unlocked, I executed the following commands:

mv ibdata1 ibdata1.bad
cp -a ibdata1.bad ibdata1

These renamed the original and then crated a new duplicate of it with the -a switch on the cp command forcing copying with greater integrity than normal. Along with the various file operations, I also created a link to my.cnf, the MySQL configuration file on Linux systems, in /etc using the following command executed by root:

ln -s /etc/mysql/ my.cnf /etc/my.cnf

While I am unsure if this made a real difference, uncommenting the lines in the same file that pertained to InnoDB tables. What directed me to these were complaints from mysqld_safe in the myhost.err log file. All I did was to uncomment the lines beginning with “innodb” and these were 116-118, 121-122 and 124-127 in my configuration file but it may be different in yours.

After all the above, the MySQL daemon ran happily and, more importantly, started when I rebooted the virtual machine. Thinking about it now, I believe that was a lack of disk space, the locking of a data file and the lack of InnoDB support that was stopping the MySQL service from running.Running commands like mysqld start weren’t yielding useful messages so a lot of digging was needed to get the result that I needed. In fact, that’s one of the reasons why I am sharing my experiences here.

In the end, creating databases and loading them with data was all that was needed for me to start see functioning websites on my (virtual) Arch Linux system. It turned out to be another step on the way to making it workable as a potential replacement for the Linux distributions that I use most often (Linux Mint, Fedora and Ubuntu).

Databases, Linux, Software, Virtualisation, Web Technologies, Web Tools

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A look at Slackware 13.0

June 5, 2010 2 comments

Some curiosity has come upon me and I have been giving a few Linux distros a spin in fVirtualBox virtual machines. One was Slackware and I recall a fellow university student using it in the mid/late 1990′s. Since then, my exploration took me into Redhat, SuSE, Mandrake and eventually to Ubuntu, Debian and Fedora. All of that bypassed Slackware so it was to give the thing a look.

While the current version is 13.1, it was 13.0 that I had to hand so I had a go with that. In many ways, the installation was a flashback to the 1990′s and I can see it looking intimidating to many computer users with its now old-fashioned installation GUI. If you can see through that though, the reality is that it isn’t too hard to install.

After all, the DVD was bootable. However, it did leave you at a command prompt and I can see that throwing many. The next step is to use cfdisk to create partitions (at least two are needed, swap and normal). Once that is done, it is time to issue the command setup and things look more graphical again. I picked the item for setting the locale of the keyboard and everything followed from there but there is a help option too for those who need it. If you have installed Linux before, you’ll recognise a lot of what you see. It’ll finish off the set up of disk partitions for you and supports ext4 too; it’s best not to let antique impressions fool you. For most of the time, I stuck with defaults and left it to perform a full installation with KDE as the desktop environment. If there is any real criticism, it is the absence of an overall progress bar to see where it is with package installation.

Once the installation was complete, it was time to restart the virtual machine and I found myself left at the command prompt. Only the root user was set up during installation so I needed to add a normal user too. Issuing startx was enough to get me into KDE (along with included alternatives like XCFE, there is a community build using GNOME too) for that but I wanted to have that loading automatically. To fix that, you need to edit /etc/inittab to change the default run level from 3 to 4 (hint: look for a line with id:3:initdefault: in it near the top of the file and change that; the file is well commented so you can find your way around it easily without having to look for specific esoteric test strings).

After all this, I ended up with a usable Slackware 130.0 installation. Login screens have a pleasing dark theme by default while the desktop is very blue. There may be no OpenOffice but KOffice is there in its place and Seamonkey is an unusual inclusion along with Firefox. It looks as if it’ll take a little more time to get to know Slackware but it looks good so far; I may even go about getting 13.1 to see how things might have changed and report my impressions accordingly. Some will complain about the rough edges that I describe here but comments about using Slackware to learn about Linux persist. Maybe, Linux distributions are like camera film; some are right for you and some aren’t. Personally, I wouldn’t thrust Slackware upon a new Linux user if they have to install it themselves but it’s not at all bad for that.

Linux, Software, Virtualisation

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An early peek at Ubuntu 9.10

August 5, 2009 2 comments

Even if the twice a year release means that changes to Ubuntu are evolutionary rather than revolutionary, that isn’t to say that curiosity doesn’t get the better of me from time to time. The result is that an early alpha version (3 at the time of writing) of the Linux distro has found a home in a VirtualBox VM on my main system. The most noticeable change so far is the inclusion of GNOME 2.27.5 with its Fedora-esque log-in screen and the movement of the shutdown and log-off paraphernalia to the System menu, which is where you find it in Debian or Fedora. On the account settings menu, there lives a link to an equivalent of the Windows Control Panel called Control Centre; the menu item is named System Preferences. For the record, I have seen it in Fedora 11 too and it does look as if Ubuntu’s GNOME implementation is looking more like a brown equivalent of Fedora. Whether this stays is anyone’s guess but a new messaging arrangement is coming into being too.

GNOME Control Centre in Ubuntu 9.10

Otherwise, there appears to be no real drama on the surface with Firefox staying at 3.0.x for now and OpenOffice moving to 3.1. Personally speaking, I’d be very surprised to seeing Firefox 3.5.x being left out though I did run into a spot of bother with the Preferences dialogue crashing it on Windows XP. Under the bonnet, the kernel is at release 2.6.31 and things seem reasonably stable at this stage. Saying that, there is a crash report icon appear every session but that has no effect apart from the visual side of things. VirtualBox Guest Additions work as they should, better than they in Windows guests if my experience provides any sort of benchmark (the display does odd things unless you keep jogging the graphics memory up and down). All in all, things appear usable if undramatic at this stage and there are a few months to go before the final release anyway.

Linux, Software, Virtualisation

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On keyboards

April 17, 2009 No comments

There cannot be too many Linux users who go out and partner a Microsoft keyboard with their system but my recent cable-induced mishap has resulted in exactly that outcome. Keyboards are such standard items that it is not so possible to generate any excitement about them, apart from RSI-related concerns. While I wasn’t about to go for something cheap and nasty that would do me an injury, going for something too elaborate wasn’t part of the plan either, even if examples of that ilk from Microsoft and Logitech were sorely tempting.

Shopping in a bricks and mortar store like I was has its pluses and its minuses. The main plus points are that you see and feel what you are buying with the main drawback being that the selection on offer isn’t likely to be as extensive as you’d find on the web, even if I was in a superstore. Despite the latter, there was still a good deal available. There were PS/2 keyboards for anyone needing them but USB ones seemed to be the main offer with wireless examples showcased too. Strangely, the latter were only available as kits with mice included, further adding to the cost of an already none too cheap item. The result was that I wasn’t lured away from the wired option.

I didn’t emerge with what would have been my first choice because that was out of stock but that’s not to say that what I have doesn’t do the job for me. Key action is soft and cushioned rather than clicky like that to which I am accustomed; some keyboards feel like they belong on a laptop but not this one. There are other bells and whistles too with a surprising number of them working. The calculator and email buttons number among these along with the play/pause, back and forward ones for a media player; I am not so convinced about the volume controls though an on-screen indicator does pop up. You’d expect a Microsoft item to be more Windows specific than others but mine works as well as anything else in the Ubuntu world and I have no reason to suspect that other Linux distros would spurn it either. Keyboards are one of those “buy-it-and-forget-it” items and the new arrival should be no different.

Hardware

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Ubuntu upgrades: do a clean installation or use Update Manager?

April 9, 2009 2 comments

Part of some recent “fooling” brought on by the investigation of what turned out to be a duff DVD writer was a fresh installation of Ubuntu 8.10 on my main home PC. It might have brought on a certain amount of upheaval but it was nowhere near as severe as that following the same sort of thing with a Windows system. A few hours was all that was needed but the question as to whether it is better to do an upgrade every time a new Ubuntu release is unleashed on the world or to go for a complete virgin installation instead. With Ubuntu 9.04 in the offing, that question takes on a more immediate significance than it otherwise might do.

Various tricks make the whole reinstallation idea more palatable. For instance, many years of Windows usage have taught me the benefits of separating system and user files. The result is that my home directory lives on a different disk to my operating system files. Add to that the experience of being able to reuse that home drive across different Linux distros and even swapping from one distro to another becomes feasible. From various changes to my secondary machine, I can vouch that this works for Ubuntu, Fedora and Debian; the latter is what currently powers the said PC. You might have to user superuser powers to attend to ownership and access issues but the portability is certainly there and it applies anything kept on other disks too.

Naturally, there’s always the possibility of losing programs that you have had installed but losing the clutter can be liberating too. However, assembling a script made up up of one of more apt-get install commands can allow you to get many things back at a stroke. For example, I have a test web server (Apache/MySQL/PHP/Perl) set up so this would be how I’d get everything back in place before beginning further configuration. It might be no bad idea to back up your collection of software sources either; I have yet to add all of the ones that I have been using back into Synaptic. Then there are closed source packages such as VirtualBox (yes, I know that there is an open source edition) and Adobe Reader. After reinstating the former, all my virtual machines were available for me to use again without further ado. Restoring the latter allowed me to grab version 9.1 (probably more secure anyway) and it inveigles itself into Firefox now too so the number of times that I need to go through the download shuffle before seeing the contents of a PDF are much reduced, though not completely eliminated by the Windows-like ability to see a PDF loaded in a browser tab. Moving from software to hardware for a moment, it looks like any bespoke actions such as my activating an Epson Perfection 4490 Photo scanner need to be repeated but that was all that I needed to do. Getting things back into order is not so bad but you need to allow a modicum of time for this.

What I have discussed so far are what might be categorised as the common or garden aspects of a clean installation but I have seen some behaviours that make me wonder if the usual Ubuntu upgrade path is sufficiently complete in its refresh of your system. The counterpoint to all of this is that I may not have been looking for some of these things before now. That may apply to my noticing that DSLR support seems to be better with my Canon and Pentax cameras both being picked up and mounted for me as soon as they are connected to a PC, the caveat being that they are themselves powered on for this to happen. Another surprise that may be new is that the BBC iPlayer’s Listen Again works without further work from the user, a very useful development. It very clearly wasn’t that way before I carried out the invasive means. My previous tweaking might have prevented the in situ upgrade from doing its thing but I do see the point of not upsetting people’s systems with an overly aggressive update process, even if it means that some advances do not make themselves known.

So what’s my answer regarding which way to go once Ubuntu Jaunty Jackalope appears? For sake of avoiding initial disruption, I’d be inclined to go down the Update Manager route first while reserving the right to do a fresh installation later on. All in all, I am left with the gut feeling is that the jury is still out on this one.

Linux, Software, Virtualisation

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  • As is commonly the case with places like these, all the views that you find expressed on here in postings and articles are mine alone and not those of any organisation with which I have any association, through work or otherwise. With regards to any comments left on the site, I reserve the right to reject any that are inappropriate. Otherwise, whatever is said is the sole responsibility of whoever is leaving the comment.