Trac uses an internal database to store its data, meaning some extra care needs to be taken when backing up a trac project. This means that we can’t just copy/tar/gz/etc the folder and we need to make sure the database is properly closed and no one is writing to it at that particular time. Of course this is useful for big installation, while for a small trac usage install, you can probably just tar gz the trac folder and be just fine. But even in that case, I would choose the safe method and do it right because it is so easy: the trac-admin command provides the hotcopy switch just for this.

Basically all you have to do is:
trac-admin <trac_project_path> hotcopy <backup_path>
and of course if you are familiar with svn you will notice that it is similar to the way you use svnadmin hotcopy
Read the rest of this entry »

This is rather silly, but I lost some time with it, so I thought to put it in a blog post as it might be useful to others. Ok, a few days ago I took over an existing cacti installation; I was working to improve it and bring in some other stuff I always do in a cacti installation (note to self, I should really put some blog posts about cacti templates I use, as that will definitely save me some time in the future). One problem I noticed was that there was a traffic interface graph that was wrong when it was going over 114Mbps. I knew what the problem was and it should have been a quick fix.

All I had to do was to change from regular 32-bit counters to 64-bit counters and increase the maximum value to 1M. I have done that, but to my surprise the graph stopped working completely for the respective interface. So I had to dig into it, and debug the problem. I was able to see that the cacti poller snmp query was failing and returning:
Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: IF-MIB::ifHCInOctets.10124

Read the rest of this entry »

Alexander Wirt announced that the lenny-backports suite is ready for uploads:
“I’m proud to announce the start of the lenny-backports distribution. All  contributors are now asked to provide new backports also for lenny-backports. But that does not mean etch-backports is dead, we will continue support for etch-backports as long as there is security support for oldstable (aka etch).”

etch-backports will still be supported for as long as there is security support for debian etch (now oldstable). People using etch-backports should probably upgrade to lenny anyway, and stop using the backports as this can now bring their system into an unstable state and break a clean upgrade path to lenny, if using potential newer packages than then one in lenny at this time.

Read the rest of this entry »

Citrix announced today that they will offer free licenses for their full XenServer virtualization solution. While Xen, the hypervisor itself was always open source, XenServer will not be released as open source, as it contains proprietary code, but will be free for anyone to download and use. I am sure that current XenServer5 clients that have paid more than $900 per server will be very ‘happy’ to hear this news . They will probably receive some special deals for Citrix Essentials, but still…

For full details: http://www.citrix.com/English/NE/news/news.asp?newsID=1687130

This post will show how to deal with the issue I had on a newly installed debian lenny xen virtual machine. I used xen-tools to create the vm using the deboostrap method, and all was fine. I installed the bash-completion package, as probably most of you, I can’t live without bash completion, but quickly found out that it was broken. Any attempt to perform a filelist completion was failing with this error:
vm11:~# tail -f /va<TAB>-bash: /dev/fd/62: No such file or directory
-bash: /dev/fd/60: No such file or directory
and this basically makes the bash completion useless. On a quick look I could easily see that the /dev/fd link was not there and that was the main cause of the problem. Still on one older lenny vm I had for a couple of months this was not happening (from what I can tell because it had an older version of the /etc/bash_completion file). There are several ways to fix this starting with the obvious one to downgrade /etc/bash_completion but I didn’t like that, so I looked for some other ways. Read the rest of this entry »

Yesterday, 14 February 2009, the Debian Project announced the official release of Debian GNU/Linux version 5.0 (codenamed “Lenny“). This comes after almost 2 years (22 months) from the previous stable release, “Etch” that was launched on 8 April 2007.

“This release includes numerous updated software packages, such as the K Desktop Environment 3.5.10 (KDE), an updated version of the GNOME desktop environment 2.22.2, the Xfce 4.4.2 desktop environment, LXDE 0.3.2.1, the GNUstep desktop 7.3, X.Org 7.3, OpenOffice.org 2.4.1, GIMP 2.4.7, Iceweasel 3.0.6 (an unbranded version of Mozilla Firefox), Icedove 2.0.0.19 (an unbranded version of Mozilla Thunderbird), PostgreSQL 8.3.6, MySQL 5.0.51a, GNU Compiler Collection 4.3.2, Linux kernel version 2.6.26, Apache 2.2.9, Samba 3.2.5, Python 2.5.2 and 2.4.6, Perl 5.10.0, PHP 5.2.6, Asterisk 1.4.21.2, Emacs 22, Inkscape 0.46, Nagios 3.06, Xen Hypervisor 3.2.1 (dom0 as well as domU support), OpenJDK 6b11, and more than 23,000 other ready-to-use software packages (built from over 12,000 source packages).”

Read the rest of this entry »

The Bcfg2 version available in debian etch is quite old (v0.8.6), while the one in lenny is newer v0.9.5.7, it still isn’t the latest stable version 0.9.6 that was released in November last year. Since this version fixes many bugs it is the version that is recommended to use in production at this time (unfortunately it breaks the reporting system, that will not be fixed until the release 1.0 planed for the next months). This post will show how we can rebuild a debian package for the latest stable bcfg2 release so we can easily deploy it on several machines.

Bcfg2 is a debian friendly project, meaning they provide inside the source package all what is needed to build a debian package very easy. We will use for this a debian etch system, but this should work on any debian based system. Read the rest of this entry »

Awstats will consider as a page hit any entry from the log it processes. By default some file extensions (for regular image types and css/js) are excluded from what awstats will consider as a page:
NotPageList="css js class gif jpg jpeg png bmp ico"(this is the default). All other file types will be counted as pages. Now, if we want to completely ignore some files, or even all the content of one folder from the awstats processing we can use the SkipFiles parameter. We might want to do this to ignore some frames, hidden pages, ajax calls, etc.

Read the rest of this entry »

If you, or your company would be interested in sponsoring the debian project here is your chance:

“The Debian project is looking for sponsors for two new official services: snapshot and data archives. Both services utilize large amounts of data and therefore require a capable machine with a large disk array that provides 10 TB of disk space to start, with the ability to be easily extended. We’d like interested sponsors to contact hardware-donations@debian.org.”

For full details: http://www.debian.org/News/2009/20090208

Description: This will show how to hide the lighttpd version to remote requests.

Useful: there is really no need to disclose this information to everyone. As shown in “Discover the web server software and version of a remote server” anyone can find valuable information from our web server banner. Hiding it  will not protect in any way from real vulnerabilities if they exist, but it will at least make their life harder. This will also not stop more complex fingerprinting programs to detect some information on the web server, but at least we should not make their life easier .

Read the rest of this entry »