Setting up MySQL on Sabayon Linux

For quite a while now, I have offline web servers for doing a spot of tweaking and tinkering away from the gaze of web users that visit what I have on there. Therefore, one of the tests that I apply to any prospective main Linux distro is the ability to set up a web server on there. This is more straightforward for some than for others. For Ubuntu and Linux Mint, it is a matter of installing the required software and doing a small bit of configuration. My experience with Sabayon is that it needs a little more effort than this and I am sharing it here for the installation of MySQL.

The first step is too install the software using the commands that you find below. The first pops the software onto the system while second completes the set up. The --basedir option is need with the latter because it won’t find things without it. It specifies the base location on the system and it’s /usr in my case.

sudo equo install dev-db/mysql
sudo /usr/bin/mysql_install_db --basedir=/usr

With the above complete, it’s time to start the database server and set the password for the root user. That’s what the two following commands achieve. Once your root password is set, you can go about creating databases and adding other users using the MySQL command line

sudo /etc/init.d/mysql start
mysqladmin -u root password ‘password’

The last step is to set the database server to start every time you start your Sabayon system. The first command adds an entry for MySQL to the default run level so that this happens. The purpose of the second command is check that this happened before restarting your computer to discover if it really happens. This procedure also is needed for having an Apache web server behave in the same way so the commands are worth having and even may have a use for other services on your system. ProFTP is another that comes to mind, for instance.

sudo rc-update add mysql default
sudo rc-update show | grep mysql

Sorting out MySQL on Arch Linux

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).

Moving from Ubuntu 10.10 to Linux Mint 10

With a long Easter weekend available to me and with thoughts of forthcoming changes in the world of Ubuntu, I got to wondering about the merits of moving my main home PC to Linux Mint instead. Though there is a rolling variant based on Debian, I went for the more usual one based on Ubuntu that uses GNOME. For the record, Linux Mint isn’t just about the GNOME desktop but you also can have it with Xfce, LXDE and KDE desktops as well. While I have been known to use Lubuntu and like its LXDE implementation, I stuck with the option of which I have most experience.

Once I selected the right disk for the boot loader, the main installation of Mint went smoothly. By default, Ubuntu seems to take care of this but Mint leaves it to you. When you have your operating system files on sdc, installation on the default of sda isn’t going to produce a booting system. Instead, I ended up with GRUB errors and, while I suppose that I could have resolved these, the lazier option of repeating the install with the right boot loader location was the one that I chose. It produced the result that I wanted: a working and loading operating system.

However, there was not something not right about the way that the windows were displayed on the desktop with title bars and window management not working as they should. Creating a new account showed that it was the settings that were carried over from Ubuntu in my home area that were the cause. Again, I opted for a less strenuous option and moved things from the old account to the new one. One outcome of that decisions was that there was a lot of use of the chown command in order to get file and folder permissions set for the new account. In order to make this all happen, the new account needed to be made into an Administrator just like its predecessor; by default, more restrictive desktop accounts are created using the Users and Groups application from the Administration submenu. Once I was happy that the migration was complete, I backed up any remaining files from the old user folder and removed it from the system. Some of the old configuration files were to find a new life with Linux Mint.

In the middle of the above, I also got to customising my desktop to get the feel that is amenable. For example, I do like a panel at the top and another at the bottom. By default, Linux Mint only comes with the latter. The main menu was moved to the top because I have become used to having there and switchers for windows and desktops were added at the bottom. They were only a few from what has turned out not to be a short list of things that I fancied having: clock, bin, clearance of desktop, application launchers, clock, broken application killer, user switcher, off button for PC, run command and notification area. It all was gentle tinkering but still is the sort of thing that you wouldn’t want to have to do over and over again. Let’s hope that is the case for Linux Mint upgrades in the future. That the configuration files for all of these are stored in home area hopefully should make life easier, especially when an in-situ upgrade like that for Ubuntu isn’t recommended by the Mint team.

With the desktop arranged to my liking, the longer job of adding to the collection of software on there while pruning a few unwanted items too was next. Having had Apache, PHP and MySQL on the system before I popped in that Linux Format magazine cover disk for the installation, I wanted to restore them. To get the off-line websites back, I had made copies of the old Apache settings that simply were copied over the defaults in /etc/apache (in fact, I simply overwrote the apache directory in /etc but the effect was the same). MySQL Administrator had been used to take a backup of the old database too. In the interests of spring cleaning, I only migrated a few of the old databases from the old system to the new one. In fact, there was an element of such tidying in my mind when I decided to change Linux distribution in the first place; Ubuntu hadn’t been installed from afresh onto the system for a while anyway and some undesirable messages were appearing at update time though they were far from being critical errors.

The web server reinstatement was only part of the software configuration that I was doing and there was a lot of use of apt-get while this was in progress. A rather diverse selection was added: Emacs, NEdit, ClamAV, Shotwell (just make sure that your permissions are sorted first before getting this to use older settings because anything inaccessible just gets cleared out; F-Spot was never there is the first place in my case but it may differ for you), UFRaw, Chrome, Evolution (never have been a user of Mozilla Thunderbird, the default email client on Mint), Dropbox, FileZilla, MySQL Administrator, MySQL Query Browser, NetBeans, POEdit, Banshee (Rhythmbox is what comes with Mint but I replaced it with this), VirtualBox and GParted. This is quite a list and while I maybe should have engaged the services of dpkg to help automate things, I didn’t on this occasion though Mint seems to have a front end for it that does the same sort of thing. Given that the community favour clean installations, it’s little that something like this is on offer in the suite of tools in the standard installation. This is the type of rigmarole that one would not draw on themselves too often.

With desktop tinkering and software installations complete, it was time to do a little more configuration. In order to get my HP laser printer going, I ran hp-setup to download the (proprietary, RMS will not be happy…) driver for it because it otherwise wouldn’t work for me. Fortune was removed from the terminal sessions because I like them to be without such things. To accomplish this, I edited /etc/bash.bashrc and commented out the /usr/games/fortune line before using apt-get to clear the software from my system. Being able to migrate my old Firefox and Evolution profiles, albeit manually, has become another boon. Without doubt, there are more adjustments that I could be making but I am happy to do these as and when I get to them. So far, I have a more than usable system, even if I engaged in more customisation than many users would go doing.

It probably is useful to finish this by sharing my impressions of Linux Mint. What goes without saying is that some things are done differently and that is to be expected. Distribution upgrades are just one example but there are tools available to make clean installations that little bit easier. To my eyes, the desktop looks very clean and fond display is carried over from Ubuntu, not at all a bad thing. That may sound a small matter but it does appear to me that Fedora and openSUSE could learn a thing or too about how to display fonts on screen on their systems. It is the sort of thing that adds the spot of polish that leaves a much better impression. So far, it hasn’t been any hardship to find my way around and I can make the system fit my wants and needs. That it looks set to stay that way is another bonus. We have a lot of change coming in the Linux world with GNOME 3 on the way and Ubuntu’s decision to use Unity as their main desktop environment. While watching both of these developments mature, it looks as if I’ll be happily using Mint. Change can refresh but a bit of stability is good too.

Turning off the admin bar in WordPress 3.1

Work on WordPress 3.1 is in full swing at the moment though I initially though that they were taking a little break after 3.0. From what I can see, many refinements are being made to the multi-blog functionality and behind-the-scenes work is ongoing on the administration screens too.

Another under-the-bonnet change has been to make WordPress less tied to MySQL since the possibility of dropping in support for an alternative such as PostgreSQL is now a reality even if it isn’t part of the default package. For now, it looks as if this is going to be plugin territory rather than default multi-database support though that may become a sensible development in the light of Oracle’s acquisition of MySQL and its sabre rattling with regard to Java patents. So far, the change to WordPress has affected my use of its database engine to power an offline version of my online photo gallery but a quick spot of code editing sorted that issue.

One more obvious alteration is going to be the addition of a WordPress.com style administration bar to the top of all content and administration screens for a user who is logged into the system. It is going to be turned on by default but there will be the option of turning it off for those among who prefer things that way. All that will be needed for this is to add the following line near the top of wp-config.php:

define( “WP_SHOW_ADMIN_BAR”, false);

The chance to see new additions like those above and be ready for is my main reason for following WordPress development. It’s best to be ready than surprised though it has to be said that the blogging or CMS platform is a very polished one these days.

Basic string searching in MySQL table columns

Last weekend, I ended up doing a spot of file structure reorganisation on the web server for www.johnhennessy.co.uk and needed to correct some file pointers in entries on my outdoors blog. Rather than grabbing a plugin from somewhere, I decided to edit the posts table directly. First, I needed to select the affected observations and this is where I needed to pick out the affected rows and edit them in MySQL Query Browser. To do that, I needed basic string searching so I opened up my MySQL eBook from Apress and constructed something like the following:

select * from posts_table where post_text like ‘%some_text%’;

The % wildcard characters are needed to pick out a search string in any part of a piece of text. There may be more sophisticated method but this did what I needed in a quick and dirty manner without further ado. Well, it was what I needed.