Tag Archive for Linux

TypeError: unable to create a wrapper for GLib.Variant

August 31, 2011 No comments

A little while ago, I wrote a piece on here telling of how I got GNOME 3 installed an working on Linux Mint. However, I have discovered since that there was an Achilles heel in the approach that I had taken: using the ricotz/testing PPA so that I could gain additional extensions for use with GNOME Shell. If this was just a repository of GNOME Shell extensions, that would be well and good but the maintainer(s) also has a more cutting edge of GNOME Shell in there too. Occasionally, updates from ricotz/testing have been the cause of introducing rough edges to my desktop environment that have resolved themselves within a few hours or days. However, updates came through in the last few days that broke GNOME Tweak Tool. When I tried running it from the command line, all I got was a load of output that included the message that heads this posting and no window popping up that I could use. That made me see sense so I stopped living dangerously by using that testing repository. Apparently, there is a staging variant too but a forum posting elsewhere on the web has warded me off from that too.

Until I encountered the latter posting, I had not heard of the ppa-purge tool and it came in handy for ridding my system of all packages from the ricotz repository and replacing with with alternatives from more stable ones such as that from the gnome3-team. This wasn’t installed on my computer so I added it in the usual fashion by issuing the following command:

sudo apt-get install ppa-purge

Once that was complete, I executes the following command with the ricotz/testing repository still active:

sudo ppa-purge testing ricotz

Once that was complete and everything was very nicely automated too, GNOME Tweak Tool was working again as intended and that’s the way that I intend keeping things. Another function of ppa-purge is that it has excised any mention of the ricotz/testing repos from my system too so nothing more can come from there.

While I was in the business of stabilising GNOME Shell on my system, I decided to add in UGR too. First, another repository needed to be added as follows:

sudo add-apt-repository ppa:ubuntugnometeam/ppa-gen
sudo apt-get update

The next steps were to install UGR once that was in place so these commands were issued to do the job:

sudo apt-get dist-upgrade
sudo apt-get install ugr-desktop-g3
sudo apt-get upgrade

While that had the less desirable effect of adding games that I didn’t need and have since removed, it otherwise worked well and I now have a new splash screen at starting up and shutting down times for my pains. Hopefully, it will main that any updates to GNOME Shell that come my way should be a little more polished too. All that’s needed now is for someone to set up a dedicated PPA for GNOME Shell Extensions so I could regain drop down menus in the top panel for things such as virtual desktops, places and other handy operations that perhaps should have been in GNOME Shell from the beginning. However, that’s another discussion so I’ll content myself with what I now have and see if my wish ever gets granted.

Linux, Software

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A waiting game

August 20, 2011 No comments

Having been away every weekend in July, I was looking forward to a quiet one at home to start August. However, there was a problem with one of my websites hosted by Fasthosts that was set to occupy me for the weekend and a few weekday evenings afterwards.

The issue appeared to be slow site response so I followed advice given to me by second line support when this website displayed the same type of behaviour: upgrade from Apache 1.3 to 2.2 using the control panel. Unfortunately for me, that didn’t work smoothly at all and there seemed to be serious file loss as a result. Raising a ticket with the support desk only got me the answer that I had to wait for completion and I now have come to the conclusion that the migration process may have got stuck somewhere along the way. Maybe another ticket is in order.

There were a number of causes of the waiting that gave rise to the title of this post. Firstly, support for low costing isn’t exactly timely and I do wonder if it’s any better for more prominent websites. Restoration of websites by FTP is another activity that takes up plenty of time as does rebuilding databases and populating them with data. Lastly, there’s changing the DNS details for a website. In hindsight, there may be ways of reducing the time demands of these. For instance, contacting a support team by telephone may be quicker unless there is a massive queue awaiting attention and there was a wait of several hours one night when a security changeover affected a multitude of Fasthosts users. Of course, it is not a panacea at the best of times as we have known since all those stories began to do the rounds in the middle of the 1990′s. Doing regular backups would help the second though the ones that I was using for the restoration weren’t too bad at all. Nevertheless, they weren’t complete so there was unfinished business that required resolution later. The last of these is helped along by more regular PC restarts so that unexpected discovery will remain a lesson for the future though I don’t plan on moving websites around for a while. After all, getting DNS details propagated more quickly really is a big help.

While awaiting a response from Fasthosts, I began to ponder the idea of using an alternative provider. Perusal of the latest digital edition of .Net (I now subscribe to the non-paper edition so as to cut down on the clutter caused by having paper copies about the place) ensued before I decided to investigate the option of using Webfusion. Having decided to stick with shared hosting, I gave their Unlimited Linux option a go. For someone accustomed to monthly billing, it was unusual to see annual biannual and triannual payment schemes too. The first of these appears to be the default option so a little care and attention is needed if you want something else. In order to encourage you to stay with Webfusion longer, the per month is on sliding scale: the longer the period you buy, the lower the cost of a month’s hosting.

Once the account was set up, I added a database and set to the long process of uploading files from my local development site using FileZilla. Having got a MySQL backup from the Fasthosts site, I used the provided PHPMyAdmin interface to upload the data in pieces not exceeding the 8 MB file size limitation. It isn’t possible to connect remotely to the MySQL server using the likes of MySQL Administrator so I bear with this not so smooth process. SSH is another connection option that isn’t available but I never use it much on Fasthosts sites anyway. There were some questions to the support people along and the first of these got a timely answer though later ones took longer before I got an answer. Still, getting advice on the address of the test website was a big help while I was sorting out the DNS changeover.

Speaking of the latter, it took a little doing and not little poking around Webfusion’s FAQ’s before I made it happen. First, I tried using name servers that I found listed in one of the articles but this didn’t seem to achieve the end that I needed. Mind you, I would have seen the effects of this change a little earlier if I had rebooted my PC earlier than I did than I did but it didn’t occur to me at the time. In the end, I switched to using my domain provider’s name servers and added the required information to them to get things going. It was then that my website was back online in some fashion so I could any outstanding loose ends.

With the site essentially operating again, it was time to iron out the rough edges. The biggest of these was that MOD_REWRITE doesn’t seem to work the same on the Webfusion server like it does on the Fasthosts ones. This meant that I needed to use the SCRIPT_URI CGI variable instead of PATH_INFO in order to keep using clean URL’s for a PHP-powered photo gallery that I have. It took me a while to figure that out and I felt much better when I managed to get the results that I needed. However, I also took the chance to tidy up site addresses with redirections in my .htaccess file in an attempt to ensure that I lost no regular readers, something that I seem to have achieved with some success because one such visitor later commented on a new entry in the outdoors blog.

Once any remaining missing images were instated or references to them removed, it was then time to do a full backup for sake of safety. The first of these activities was yet another consumer while the second didn’t take so long and I need to do this more often in case anything happens. Hopefully though, the relocated site’s performance continues to be as solid as it is now.

The question as to what to do with the Fasthosts webspace remains outstanding. Currently, they are offering free upgrades to existing hosting packages so long as you commit for a year. After my recent experience, I cannot say that I’m so sure about doing that kind of thing. In fact, the observation leaves me wondering if instating that very extension was the cause of breaking my site. In fact, it appears that the migration from Apache 1.3 to 2.2 seems to have got stuck for whatever reason. Maybe another ticket should be raised but I am not decided on that yet. All in all, what happened to that Fasthosts website wasn’t the greatest of experiences but the service offered by Webfusion is rock solid thus far. While wondering if the service from Fasthosts wasn’t as good as it once was, I’ll keep an open mind and wait to see if my impressions changes over time.

Scripting, Web, Web Development, Web Technologies, Web Tools

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Setting up GNOME 3 on Arch Linux

July 22, 2011 8 comments

It must have been my curiosity that drove me to exploring Arch Linux a few weeks ago. Its coming on a Linux Format DVD and a few kind words about its being a cutting edge distribution were enough to set me installing it into a VirtualBox virtual machine for a spot of investigation. In spite of warnings to the contrary, I took the path of least resistance with the installation even though I did look among the packages to see if I could select a desktop environment to be added as well. Not finding anything like GNOME in there, I left everything as defaulted and ended up with a command line interface as I suspected. The next job was to use the pacman command to add the extras that were needed to set in place a fully functioning desktop.

For this, the Arch Linux wiki is a copious source of information though it didn’t stop me doing things out of sequence. That I didn’t go about perusing it in a linear manner was part of the cause of this but you have to know which place to start first as well. As a result, I have decided to draw everything together here so that it’s all in one place and in a more sensible order even if it wasn’t the one that I followed.

The first thing to do is go adding X.org using the following command:

pacman -Syu xorg-server

The -Syu switch tells pacman to update the package list, upgrade any packages that require it and add the listed package if it isn’t in place already; that’s X.org in this case. For my testing, I added xor-xinit too. This puts that startx command in place. This is the command for adding it:

pacman -S xorg-xinit

With those in place, I’d go adding the VirtualBox Guest Additions next. GNOME Shell requires 3D capability so you need to have this done while the machine is off or when setting it up in the first place. This command will add the required VirtualBox extensions:

pacman -Syu virtualbox-guest-additions

Once that’s done, you need to edit /etc/rc.conf by adding “vboxguest vboxsf vboxvideo” within the brackets on the MODULES line and adding “rc.vboxadd” within the brackets on the DAEMONS line. On restarting everything should be available to you but the modprobe command is there for any troubleshooting.

With the above pre-work done, you can set to installing GNOME and I added the basic desktop from the gnome package and the other GNOME applications from the gnome-extra one. GDM is the login screen manager so that’s needed too and the GNOME Tweak Tool is a very handy thing to have for changing settings that you otherwise couldn’t. Here are the commands that I used to add all of these:

pacman -Syu gnome
pacman -Syu gnome-extra
pacman -Syu gdm
pacman -Syu gnome-tweak-tool

With those in place, some configuration files were edited so that a GUI was on show instead of a black screen with a command prompt, as useful as that can be. The first of these was /etc/rc.conf where “dbus” was added within the brackets on the DAEMONS line and “fuse” was added between those on the MODULES one.

Creating a file named .xinitrc in the root home area with the following line in there makes running a GNOME session from issuing a startx command:

exec ck-launch-session gnome-session

With all those in place, all that was needed to get a GNOME 3 login screen was a reboot. Arch is so pared back that I could login as root, not the safest of things to be doing so I added an account for more regular use. After that, it has been a matter of tweaking the GNOME desktop environment and adding missing applications. The bare bones installation that I allowed to happen meant that there were a surprising number of them but that isn’t hard to fix using pacman.

All of this emphasises that Arch Linux is for those who want to pick what they want from an operating system rather than having that decided for you by someone else, an approach that has something going for it with some of the decisions that make their presence felt in computing environments from time to time. There’s no doubt that this isn’t for everyone but documentation is complete enough for the minimalism not to be a problem for experienced Linux users and I certainly managed to make things work for me once I got them in the right order. Another thing in its favour is that Arch also is a rolling distribution so you don’t need have to go though the whole set up routine every six months unlike some others. So far, it does seem stable enough and even has set me to wondering if I could pop it on a real computer sometime.

Linux, Software

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Adding GNOME 3 to Linux Mint 11

June 3, 2011 27 comments

On the surface of it, this probably sounds a very strange thing to do: choose Linux Mint because they plan to stick with their current desktop interface for the foreseeable future and then stick a brand new one on there. However, that’s what last weekend’s dalliance with Fedora 15 caused. Not only did I find that I could find my way around GNOME Shell but I actually got to liking it so much that I missed it on returning to using my Linux Mint machine again.

The result was that I started to look on the web to see if there was anyone else like me who had got the same brainwave. In fact, it was Mint’s being based on Ubuntu that allowed me to get GNOME 3 on there. The task could be summarised as involving three main stages: getting GNOME 3 installed, adding extensions and adding the Cantarell font that is used by default. After these steps, I gained a well-running GNOME 3 desktop running on Linux Mint and it looks set to stay that way unless something untoward has yet to emerge.

Installing GNOME 3

The first step is to add the PPA repository for GNOME 3 using the following command:

sudo add-apt-repository ppa:gnome3-team/gnome3

The, it was a case of issuing my usual update/upgrade command:

sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade

When that had done its thing and downloaded and installed quite a few upgrades along the way, it was time to add GNOME Shell using this command:

sudo apt-get install gnome-shell

When that was done, I rebooted my system to be greeted by a login screen very reminiscent of what I had seen in Fedora.While compiling this piece, I have seen that GNOME Session could need to be added before GNOME Shell but I do not recall doing so myself. Maybe dependency resolution kept any problems at bay but there weren’t any issues that I could remember beyond things not being configured as fully as I would have liked without further work. For sake of safety, it might be a good idea to run the following before adding GNOME Shell to your PC.

sudo apt-get install gnome-session && sudo apt-get dist-upgrade

Configuration and Customisation

Once I had logged in, the desktop that I saw wasn’t at all unlike the Fedora one and everything seemed stable too. However, there was still work to do before I was truly at home with it. One thing that was needed was the ever useful GNOME Tweak Tool. This came in very handy for changing the theme that was on display to the standard Adwaita one that caught my eye while I was using Fedora 15. Adding buttons to application title bars for minimising and maximising their windows was another job that the tool allowed me to do. The command to get this goodness added in the first place is this:

sudo apt-get install gnome-tweak-tool

The next thing that I wanted to do was go adding some extensions so I added a repository from which to do this using the command below. Downloading them via Git and compiling them just wasn’t working for me so I needed another approach.

sudo add-apt-repository ppa:ricotz/testing

With that is place, I issued the below commands to gain the Dock, the Alternative Status Menu and the Windows Navigator. The second of these would have added a shutdown option in the me-menu but it seems to have got deactivated after a system update. Holding down the ALT key to change the Suspend entry to Power off… will have to do me for now. Having the dock is the most important and that thankfully is staying the course and works exactly as it does for Fedora.

sudo apt-get install gnome-shell-extensions-dock
sudo apt-get install gnome-shell-extensions-alternative-status-menu
sudo apt-get install gnome-shell-extensions-windows-navigator

Adding Cantarell

The default font used by GNOME 3 in various parts of its interface is Cantarell and it was defaulting to that standard sans-serif font on my system because this wasn’t in place. That font didn’t look too well so I set to tracking the freely available Cantarell down on the web.  When that search brought me to Font Squirrel, I downloaded the zip file containing the required TTF files. The next step was to install them and, towards that end, I added Fontmatrix using this command:

sudo apt-get install fontmatrix

That gave me a tool with a nice user interface but I made a mistake when using it. This was because I (wrongly) thought that it would copy files from the folder that I told the import function to use. Extracting the TTF files to /tmp meant that would have had to happen but Fontmatrix just registered them instead. A reboot confirmed that they hadn’t been copied or moved at all and I had rendered the user interface next to unusable through my own folly; the default action in Ubuntu and Linux Mint is that files are deleted from /tmp on shutdown. The font selection capabilities of the GNOME Tweak Tool came in very handy for helping me converting useless boxes into letters that I could read. Another step was to change the font line near the top of the GNOME Shell stylesheet (never thought that CSS usage would end up in places like this…) so that Cantarell wasn’t being sought and text in sans-serif font replaced grey and white boxes. The stylesheet needs to be edited as superuser so the following command is what’s needed for this and, while I used sudo, gksu is just as useful here if it isn’t what I should have been using.

sudo gedit /usr/share/gnome-shell/theme/gnome-shell.css

Once I had extricated my system from that mess, a more conventional approach was taken and the command sequence below was what I followed, with extensive use of sudo to get done what I wanted. A new directory was created and the TTF files copied in there.

cd /usr/share/fonts/truetype
sudo mkdir ttf-cantarell
cd ttf-cantarell
sudo mv /tmp/*.ttf .

To refresh the font cache, I resorted to the command described in a tutorial in the Ubuntu Wiki:

sudo fc-cache -f -v

Once that was done, it was then time to restore the reference to Canterell in the GNOME Shell stylesheet and reinstate its usage in application windows using the GNOME Tweak Tool. Since then, I have suffered no mishap or system issue with GNOME 3. Everything seems to be working quietly and I am happy to see that replacement of Unity with the GNOME Shell will become an easier task in Ubuntu 11.10, the first alpha release of which is out at the time of my writing these words. Could it lure me back from my modified instance of Linux Mint yet? While I cannot say that I am sure of those but it certainly cannot be ruled out at this stage.

Linux, Software

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Pondering storage options

June 1, 2011 One comment

The combination of curiosity and a little spare time had me browsing online computing technology stores recently. A spot of CD and DVD burning brought on by a flurry of Linux distribution testing reminded me of the possibility. Because I have built up a sizeable library of digital photos, ensuring that I have backups of them is something that needs doing. A 2 GB Samsung external hard drive is brought to life every now and again for that purpose but the prospect of using Blu-Ray discs has appealed to me. After all capacities of 25 GB for single layer discs and 50 GB for dual layer ones sound not inappropriate for my purposes. However, they aren’t a cheap option at the time of writing with each disc costing in the region of £3-4 at one place where I was looking. The cost of BD writers themselves seems not to be so bad though with a few in the £60-100 bracket; any lower than this and you could end up with a combo drive that reads Blu-Ray discs and writes to DVD’s and CD’s so a modicum of concentration is needed. As attractive as the idea might be, the cost of BD media means that I’ll wait a little while before deciding to take the plunge. The price premium at the moment is a reminder of the way that things used to be when CD and DVD writers first came on the market. It is very telling when discs come packaged in jewel cases, something that you won’t see too often with CD’s or DVD’s.

Another piece of storage excitement that hasn’t escaped me is the advent of SSD hard drives. With no moving parts like in conventional hard drives, they bring a speed boost. Concerns about their lifetimes and the numbers of read/write events per drive would stall me when it comes to storing personal data on them but using them for the likes of operating system files sounds attractive, especially with my partiality to Linux perhaps not hammering drives so much. As with any new technology, there is a price premium though a drive big enough for hosting an operating system can be acquired for less than £100. As with many of my hardware purchase brainwaves, there’s no rush but this is an option that I’ll keep at the back of my mind.

Another appealing notion is the idea of getting a NAS so that files can be shared between a few computers. While I have seen prices starting at just above £70 for single disk enclosures, these generally are a more expensive option than external drives and that’s before you consider the cost of any hard drives. Nevertheless, the advantages of a unit containing more than a single hard drive while operating as a print server for any compatible printer too. When you get to 4 or 5 hard drive trays, then the cost has mounted but that could be when they pay their way too. What reminded me of these was a bookazine on home networking that I recently found at a branch of WHSmith’s and their attractions are subject to the networking side of things being made to work without a drama. Once that’s out of the way, then their usefulness really does appeal.

Mulling over all these brainwaves is one thing but it doesn’t mean that the purse strings will become too loose in this age of economic constraint. In fact, pondering them may serve to staunch any impulse purchases. Sometimes, a spot of virtual shopping serves to control things rather than losing the run of oneself.

Hardware, Imaging

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On Upgrading to Linux Mint 11

May 31, 2011 One comment

For a Linux distribution that focuses on user friendliness, it does surprise me that Linux Mint offers no seamless upgrade path. In fact, the underlying philosophy is that upgrading an operating system is a risky business. However, I have been doing in-situ upgrades for both Ubuntu and Fedora for a few years without any real calamities. A mishap with a hard drive that resulted in lost data in the days when I mainly was a Windows user places this into sharp relief. These days, I am far more careful but thought nothing of sticking a Fedora DVD into a drive to move my Fedora machine from 14 to 15 recently. Apart from a few rough edges and the need to get used to GNOME 3 together with making a better fit for me, there was no problem to report. The same sort of outcome used to apply to those online Ubuntu upgrades that I was accustomed to doing.

The recommended approach for Linux Mint is to backup your package lists and your data before the upgrade. Doing the former is a boon because it automates adding the extras that a standard CD or DVD installation doesn’t do. While I did do a little backing up of data, it wasn’t total because I know how to identify my drives and take my time over things. Apache settings and the contents of MySQL databases were my main concern because of where these are stored.

When I was ready to do so, I popped a DVD in the drive and carried out a fresh installation into the partition where my operating system files are kept. Being a Live DVD, I was able to set up any drive and partition mappings with reference to Mint’s Disk Utility. What didn’t go so well was the GRUB installation and it was due to the choice that I made in one of the installation screens. Despite doing an installation of version 10 just over a month ago, I had overlooked an intricacy of the task and placed GRUB on the operating system files partition rather than at the top level for the disk where it is located. Instead of trying to address this manually, I took the easier and more time-consuming step of repeating the installation like I did the last time. If there was a graphical tool for addressing GRUB problems, I might have gone for that instead but am left wondering at why there isn’t one included at all. Maybe it’s something that the people behind GRUB should consider creating unless there is one out there already about which I know nothing.

With the booting problem sorted, I tried logging in only to find a problem with my desktop that made the system next to unusable. It was back to the DVD and I moved many of the configuration files and folders (the ones with names beginning with a “.”) from my home directory in the belief that there might have been an incompatibility. That action gained me a fully usable desktop environment but I now think that the cause of my problem may have been different to what I initially suspected. Later I discovered that ownership of files in my home area elsewhere wasn’t associated with my user ID though there was no change to it during the installation. As it happened, few minutes with the chown command were enough to sort out the permissions issue.

The restoration of the extra software that I had added beyond what standardly gets installed was took its share of time but the use of a previously prepared list made things so much easier. That it didn’t work smoothly because some packages couldn’t be found the first time around so another one was needed. Nevertheless, that is nothing compared to the effort needed to do the same thing by issuing an installation command at a time. Once the usual distribution software updates were in place, all that was left was to update VirtualBox to the latest version, install a Citrix client and add a PHP plugin to NetBeans. Then, next to everything was in place for me.

Next, Apache settings were restored as were the databases that I used for offline web development. That nearly was all that was needed to get offline websites working but for the need to add an alias for localhost.localdomain. That required installation of the Network Settings tool so that I could add the alias in its Hosts tab. With that out of the way, the system had been settled in and was ready for real work.

In light of some of the glitches that I saw, I can understand the level of caution regarding a more automated upgrade process on the part of the Linux Mint team. Even so, I still am wondering if the more manual alternative that they have pursued brings its own problems in the form of those that I met. The fact that the whole process took a few hours in comparison to the hour taken by the in-situ upgrades that I mentioned earlier is another consideration that makes you wonder if it is all worth it every six months or so. Saying that, there is something to letting a user decide when to upgrade rather than luring one along to a new version, a point that is more than pertinent in light of the recent changes made to Ubuntu and Fedora. Whichever approach you care to choose, there are arguments in favour as well as counterarguments too.

Linux, Software

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