Rob Garth| Mildly Useful Stuff

I really should read man pages. I had no idea that rpm could do rollbacks with just a couple of config changes, and that it was supported in yum.

This would have come in really handy last week. I upgraded an out of date file server and the latest samba broke Directory authentication, which was not cool and file shares cold not be authenticated until the problem was solved. CentOS do not keep old packages in their repos. I had to compile a FC6 version of samba to rollback to a working state until I investigated and found a patch.

The bug is dated May, the patch has been out for months, and the fix is still not in official repos.

Anyway back to rollbacks, 2 steps:

1. In /etc/yum.conf add the line: 
   tsflags=repackage
2. In /etc/rpm/macos (create it if it does not exist), add the line:
   %_repackage_all_erasures 1

Now if the update or install clobbers something, you can roll back packages to their former state just with a simple rpm command.

Examples:

rpm -Uhv –rollback ‘9:00 am’,
rpm -Uhv –rollback ‘4 hours ago’,
rpm -Uhv –rollback ‘december 25′.

Fedora 10 is out. This won’t be a review, dozens have already popped up across the interweb.

Seriously it is an awesome release, I have been running it since the beta release. Fedora has often been seen by many as a not a lot more than a preview release for redhat and a test bed for bleeding edge. But F10 is a solid and polished OS and a worthy install on any machine.

One bug I have encountered so far was on a VM install, the fonts were massive, fonts set to 6 seemed a little big. Turns out the display detection can’t correctly work out the DPI of my screen. If you have this problem simply create an ~/.Xdefaults, or edit the file if you already have one, and add this line:

Xft.dpi: 100

Restart X and the problem should go away, you may need to restart the font server as well. Then you can turn your fonts up to 11!

Wow déjà vu. So gnome-vfs is still brain dead. Of course NFS4 is going to be used at some point for home directories and need trash support. Why is the list of supported filesystems still hard-coded in a c file?

Follow the instructions from the previous post, modify them to say nfs4 instead of fuse.

Update: 13/11/2008

Patch file you can apply to the SRPM of gnome-vfs: gnome-vfs-2162-nfs4-trash.patch

My latest lab build is using nfs4 to mount home directories.

Kerberos authentication requires the time to synced before it will work. Redhat (CentOS) tries mounting Network filesystems before syncing the time on startup. Can anyone else see the problem?

If any of our lab machines have their time out by more than 5 minutes the mount will fail.

I have changed the startup priority of ntpd from 58 to 12, and this has fixed the problem.

As ntpd only requires networking to work, I cannot understand why it starts at 58, but problem solved.

Found this great article on doing triple boot without needing grub to boot windows.

http://www.anomalousanomaly.com/2008/10/31/triple-booting-your-mac/

I have been setting up an Xdmx render wall. When finished it will be a 3×3 rear projected screen, with 9 computers (CentOS 5 installs) and 18 projectors for 3d visualization.

For a couple of years now Xdmx has been rolled into the Xorg source and getting it configured is really not that hard. When I have ironed out this install I may write a howto. But while some stuff was working just fine and dandy most apps that use a modern widget library for the UI (ala GTK or QT) were failing to render fonts properly, not drawing icons, messing up colors and just not looking right in general.

I scoured the interweb for answers, and the main thing I saw was just forum posts instructing users to turn of the Xorg render extension. This works, though makes the rendering of windows very, very slow. On what should be a high performance render wall I have an issue with this.

Anyway, I eventually found this post, and figured it was worth a try. And it Worked! brilliant! QT, GTK, Firefox, everything is looking peachy.

I threw it together in this patch file which I applied to the SRPM for xorg-x11-server.

huh? I can’t seem to find pam_mount for CentOS 5. RPMForge seems to have the build logs for it, but yum can’t see the rpm to install and neither can I.

Pretty simple to fix, a bit lazy, but it will only take you 5 minutes.

Grab the rpm sources for libHX and pam_mount from your local Fedora 9 mirror. I got mine from here:

http://mirror.aarnet.edu.au/pub/fedora/linux/updates/9/SRPMS/pam_mount-0.41-2.fc9.src.rpm
http://mirror.aarnet.edu.au/pub/fedora/linux/updates/9/SRPMS/libHX-1.18-1.fc9.src.rpm

Build the libHX source:

# rpmbuild --rebuild libHX-1.18-1.fc9.src.rpm

Install the libHX rpm and the libHX-devel rpm. Now build pam_mount the same way:

# rpmbuild --rebuild pam_mount-0.41-2.fc9.src.rpm

Use “yum localinstall” to install pam_mount as it probably needs to grab a perl XML module as well.

I went to the zoo yesterday, the only reason this is making my blog is that while there I played with a Qik app for the iphone (if yours is jailbroken). Instant video streams are cool, even if I have no talent as a film maker. Check it out: http://www.qik.com/robg.

http://www.kroah.com/log/linux/lpc_2008_keynote.html

They don’t play with the other kids nice. They share when its everybody else’s turn only.

I have thought for ages that Ubuntu seem to get a bunch of credit for the hard work of some dedicated gnome hackers, working predominantly for Redhat and Novell and a bit of energy spent on theming (can we get over brown please). I know that is not entirely fair, the 1 CD live/install thing is pretty smart.

But Ubuntu is the most popular distro for users, and that to me seems unhealthy. A huge user base all running a distro which really does nothing to aid the development of Linux on a community wide level.

Update:

I know This article is talking about Kernel, X.org and system level development, not a mention of gnome. The above is just my observation.

Why do PC users think Publisher is a standard application. The amount of times I have received a publisher file in an email. Listen up people, Linux and Apple users cannot use Publisher files (for that matter neither can BeOS/OS2/any unix variant/anything other than windows users).

I know I could probably use wine, or a vmware image. But I don’t want to. The fact is Publisher is a second rate application, and I don’t want to touch it.

But to the point! I just found pdfonline.com. This is not an advertisement, in fact I didn’t read the usage terms and my email address may very well have been sent to a spam king somewhere. But needless to say their online converter worked, and I converted a publisher attachment, it turns out wasn’t worth bothering with, into a pdf document.

Suck that you publisher users! I will not be soiled by your poor software choices.