Still disk latency problems with Kernel 2.6.30

I’m still having massive disk latency issues with Linux. They started after I build myself a Core 2 Duo system and switched to 64bit Linux. I wrote about it here, here and here. This workaround appeared to fix the problem first, but after some time and filling up the disk space the latency problems were back on my XFS file systems.

This whole time I’m mostly succeeding in working around the problem by either delaying the job until the time when I’m not recording some music or video or using the much smaller root-partition as scratch space DVD creation. The programs, which pretty reliable trigger the problem are avidemux2 and dviauthor. I’m using avidemux2 to remove any advertisement from a recorded MPEG2 stream. Once I write the output file beside the original file on the same file system the problem is usually triggered. When I’m writing to /tmp on the much smaller root-partition I get by without triggering the latency problem. The same is true, when dviauthor prepares the DVD file structure. When the DVD structure is prepared on the same file system as the originating file, the problem is triggered and not, when written to /tmp.

During the development cycle of kernel 2.6.30 there was much discussion on the net about fixes of latency problems, however primarily in connection to EXT3 and EXT4 file systems. Still I was hoping, that some fix in 2.6.30 would have improved the latency problem for me and my XFS file systems as well.

It appears however, that it is not the case. avidemux2 and dviauthor still trigger the problem. People on the Gentoo forums seem to agree, that the situation might have improved, but isn’t fixed yet. I need to convince myself to backup the data on my multimedia partition and change the file system to EXT4 to see, if it might change the behaviour. This is really a problem, which decreases my trust in Linux.

Problems with libstdc++-v3 on Gentoo

I didn’t do any digital photo work for some time with Bibble Pro, however recently I wanted to do something and was greeted with a “Segmentation Fault”. Bibble is a 32bit application, that I’m running on 64bit Gentoo Linux. This is what I got:

$ LD_LIBRARY_PATH=/usr/lib/bibblelabs/bibblepro/libs bibblepro
bibblepro: /usr/lib32/libstdc++.so.5: no version information available (required by bibblepro)
bibblepro: /usr/lib32/libstdc++.so.5: no version information available (required by bibblepro)
AppPath: /usr/bin
SysHome: /usr/lib/bibblelabs/bibblepro/
Userhome set to /root/.bibble
Log
Late init
... messages deleted ...
Speicherzugriffsfehler (Segmentations Fault)

Apparently it has something to with the libstdc++.so.5 (libstdc++.so.5.0.7). Checking the compilation date of the binary package showed, that it was recompiled around the middle of February 2009. With that recompilation something must have gone wrong (newer compiler or whatever). Once I replaced the libstdc++.so.5.0.7 with a version compiled on a native 32bit Gentoo system, Bibble was working just fine again.

BTW, I noticed that there is now a public preview version of Bibble 5. This version is in the making for quite some time now. Bibble 4 is really getting long in the tooth. I hope, they can release something sometime soon.

A4 Paper CD Case in SVG

If you search on delicious for “paper cd case” apart from other you’ll find these two pages (1, 2), which present Web forms. The forms allow you to enter some text and after submitting offers you to download a PDF file, which, when printed, allows you to fold a CD case from paper. Another alternative is this page.

This all works very well. I received some pretty “Wow”s after showing those CD cases to friends. However for the times, when I backup my growing MP3 collection to DVD I wanted a bit more influence, on what can be printed on the case. Therefore I duplicated the folding lines in a SVG file. Once loaded into Inkscape, you have all Inkscape tools available to style the CD case appropriately.