Nvidia, Twinview and Samsung Syncmaster

I bought a new Samsung Syncmaster T200 and wanted to configure Nvidia's Twinview. Once plugged in, nvidia-settings told me my new screen's native resolution would be 1024x768. WTF?

Well, after 2h googling and asking on IRC I found some page about custom EDIDs (with that the screen can tell your computer which resolutions it supports and so on). Everything I had to do was dumping the EDID of my first screen (using nvidia-set) and adding Option "CustomEDID" "DFP-1:/etc/X11/dfp1-edid.dat" to Section "Device" in xorg.conf.

Here you can download my EDID file if you don't have one.

NFS and crossmnt

Yesterday I restarted my NFS server and today I noticed I couldn't access some shares. I've set it up like that:

/srv/nfs 192.168.4.1/24(crossmnt,rw,sync,no_subtree_check)
/srv/nfs/foo 192.168.4.1/24(crossmnt,nohide,rw,sync,no_subtree_check)

/srv/nfs mounted to /mnt/nfs

When I now wanted to go to /mnt/nfs/foo I got a permission error which is strange because I DID export /srv/nfs/foo and use crossmnt for /srv/nfs and even nohide (manpage says you only need crossmnt for /srv/nfs and then just export /srv/nfs/foo).

After some fiddling (well, actually when I gave up) I found out that you have to mount /srv/nfs/foo somewhere else (I mounted it to /mnt/foo) before you can go to /mnt/nfs/foo. Once you did that you can unmount it again, but you can now access /mnt/nfs/foo.

The expected behaviour would be mounting /srv/nfs to /mnt/nfs and beeing able to cd to /mnt/nfs/foo.

ALSA vs OSS

Today I tested some stuff on my desktop and I had to boot a different system. I still wanted to listen to music so I took some other computer on which I haven't yet installed OSS.
I must say, the difference between ALSA and OSS is quite big. OSS has way better sound quality ;)

If you want to hear it yourself: http://bluewind.at/stuff/private/alsa_vs_oss.ogg (2.3MB)
The first part is ALSA, the second OSS.

Finally ext4 ...or not?

I bought a new HDD and set up RAID 1 with LVM and ext4. (I made it using mkfs.ext4) I was just about to rm my backups I stored on my other disks when rsync failed and I wasn't able to access my new partition anymore. Everything threw I/O Errors.
I wanted to run fsck, but I told me the disk was in use (it wasn't). Couldn't figure out what was the problem so I rebooted and got an error, telling that mount can't mount the partition because it's not ext4 (as I specified in /etc/fstab).
Well I started fsck.ext4 and it threw quite a lot of errors and after some time it started to loop.

Restarting e2fsck from the beginning...
/dev/mapper/VolGroup00-data contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Root inode is not a directory.  Clear? yes

Inode 5 has illegal block(s).  Clear? yes

Illegal block #12738657 (1613830228) in inode 5.  CLEARED.
Illegal block #12738658 (3211906433) in inode 5.  CLEARED.
Illegal block #12738659 (478689490) in inode 5.  CLEARED.
Illegal block #12738660 (3876020224) in inode 5.  CLEARED.
Illegal block #12738661 (1007945148) in inode 5.  CLEARED.
Illegal block #12738662 (1205590462) in inode 5.  CLEARED.
Illegal block #12738663 (3567108197) in inode 5.  CLEARED.
Illegal block #12738664 (3575479245) in inode 5.  CLEARED.
Illegal block #12738665 (2383729051) in inode 5.  CLEARED.
Illegal block #12738666 (619555458) in inode 5.  CLEARED.
Illegal block #12738667 (3902957544) in inode 5.  CLEARED.
Too many illegal blocks in inode 5.
Clear inode? yes

Restarting e2fsck from the beginning...
/dev/mapper/VolGroup00-data contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Root inode is not a directory.  Clear? yes

Inode 5 has illegal block(s).  Clear? yes

Illegal block #12738668 (1246693144) in inode 5.  CLEARED.
Illegal block #12738669 (2312789758) in inode 5.  CLEARED.
Illegal block #12738670 (332492032) in inode 5.  CLEARED.
Illegal block #12738671 (3850324777) in inode 5.  CLEARED.
Illegal block #12738672 (2442788202) in inode 5.  CLEARED.
Illegal block #12738673 (4227858239) in inode 5.  CLEARED.
Illegal block #12738676 (311437445) in inode 5.  CLEARED.
Illegal block #12738677 (4016009761) in inode 5.  CLEARED.
Illegal block #12738678 (3776456913) in inode 5.  CLEARED.
Illegal block #12738679 (528482688) in inode 5.  CLEARED.
Illegal block #12738680 (1343549598) in inode 5.  CLEARED.
Too many illegal blocks in inode 5.
Clear inode? yes

Now I knew my FS actually died :( I was maybe 3h old.

Here's the command that killed it:
rsync -rvtlpEog --safe-links ~/backup/mistral_backup/ mistral_backup/ --progress

To all ext4 users: Make backups on some different FS! Ext4 is NOT stable!

Update:
The problem could be that I didn't wait for the RAID to finish syncing.

Arch64, OSS and Flash

Some time ago Adobe finally brought the Flashplugin for 64-bit. To get sound working with OSS I had to use the ALSA-wrapper as described here. That worked well for some time, but around 2 or 3 weeks ago flash suddenly stopped working.

Every flash film was damn slow. It felt as if I was running on 100MHz or something. Maybe 1 picture every 5 seconds. Sound was a bit better, but out of sync and stopped sometimes. CPU usage was only 3% and atop nor iotop showed anything suspicious.

I didn't know why because I didn't upgrade anything nor did I change any config file. I googled a bit and asked around, but apparently nobody had a solution.

Then I just ignored that and today I wanted to try if it works again. So I went to youtube, disabled HQTube (A script to play youtube files in mplayer) and started a video. As you can imagine it still didn't work.

I asked the guys in #archlinux.de and we tried some things like adding a new user, using a different Browser, taking out some RAM because strace segfaulted with an error telling that the RAM was bad and finally installing a new system on a different HD.

There I installed everything needed to run Firefox with Flash and guess what. It worked! That meant that my hardware was actually okay so I rebooted the old system and tried to find the cause.

First I thought it might be uvesafb (which still doesn't work with widescreen resolutions). Then I tried using a new xorg.conf without the new fancy HAL stuff and starting X without slim.

Nothing helped and the guys in the IRC didn't have a clue either. But then I remembered that the second system, where flash worked, didn't have any sound. So I disabled OSS and tried again. Worked!! Suddenly I knew what was wrong:
I've set "vmix0-src" to "Production" because I read somewhere that it wouldn't take much CPU, but sound a bit better. Actually it didn't need more when running mplayer, mpd or vlc. Nevertheless I set it back to "Fast" and suddenly flash worked again.

That's really the strangest bug I've ever seen and I have a message for everyone who uses (only) the ALSA API in their programs:

Switch to OSS. It's better:

• OSS wastes less ressources than ALSA.
• OSS is able to let multiple programs use the same soundcard to output sound in parallel. ALSA needs an overlay (which again wastes ressources) to do that.

If you need more see here.

Special Thanks to IGProLin for telling me to install a second system.

New wallpaper section

The new wallpaper section shows thumbnails of all wallpapers. If a thumbnail doesn't exists it's generated.
http://bluewind.at/stuff/wallpapers/

Needs PHP and Imagick.

If anyone wants the code feel free to write an email.

Terminal line wrap bug

The line wrap (in every terminal) doesn't work correctly once you have color codes in your PS1.

Most site give you codes like \e[0;31m, but sadly these codes ruin the line wrap so after some letters your cursor jumps to the beginning of the very line it is on and overwrites your PS1. Once this line is full it jumps to the next line as it is supposed to.

Thanks to the Archlinux Forums I finally found a way to fix it. The fixed version of the code mentioned earlier is \[\e[0;31m\].

But if you have a function in the .bashrc you should not use those codes as they will cause some backslashes in the output.

Screenshot 26.7

Openbox theme: http://bl1nks.deviantart.com/art/Vorta-for-Openbox-92849348
Needed gtk theme: http://fratrip.deviantart.com/art/Vorta-Suite-87991631

Screenshot 19.7.08

My new Archlinux. Think I love it and won't switch back to Windows.
If you have any questions please ask them here.

OS: ArchLinux (Core Dump)
Kernel: 2.6.25-ARCH
DE: Gnome
WM: Openbox
WM Theme: Onyx
GTK Theme: Mist
Icons: gTangish-2.0a1
Font: Sans 10
Background: Link. If you like it please vote von gnome-look.org.

Random freezes

Update 2:

I finally found the reason for the freezes. More info: http://bugs.archlinux.org/task/10979

Thanks to dolby for asking me to update to testing. Now I can really use my Arch.

Update:

The problems still occures, but now I've set up a process logger because before the freez conky showed me 100% CPU. Then it went to ?2.147.483.648% CPU and froze. We'll see which process it is. (hopefully)

Old Post:

I'm using Archlinux for some days now and lately experienced something really odd. While watching videos, surfing or chatting my computer freezed randomly.Sometimes after 30 minutes, sometimes after some hours.

At first I had no idea what caused this, but after some hours of googling I found out that newer Nvidia drivers don't work very well with Compiz. I also found an article describing a way to fix this, but it didn't work for me. Sadly.

Since I knew it is caused by Compiz I tried disabling it, but that caused an instant freez. When I rebooted and logged in with my user it froze just 5 seconds after entering the password. I rebooted again and it froze just after entering the pass.

The only way to get rid of Compiz was to hit Alt+Crtl+F1 and remove it without logging in on the X-Server. Yet I haven't had any freezes.