Xupeng's blog

圆外之大，心向往之

Sun 被 Oralce 收购，Virtualbox 前途未卜

Sun 被 Oralce 收购了，我担心我没有新版本的 Virtualbox 用了……

Virtualbox 是我最喜欢的桌面虚拟化软件，目前的最新 release 是 2.2.0。我之所以喜欢 Virtualbox，是因为 Virtualbox 实在是：

VMWare ESXi 3.5.0-153875 on HP 520 laptop: “PCPU 1 locked up…”

For the sake of testing our product(krugle) easily, I installed VMWare ESXi 3.5.0 build 153875 on a HP laptop(HP 520) before the new server is delivered to our office, but unfortunately it failed to work, for several times it just threw me a screen with purple background, which is much like M$’s famous blue screen ;) it said “PCPU 1 locked up. Failed to ack TLB invalidate…”, here is one of the screenshots I took when the errors occurred: vmware-exsi But I was not surprised at all, because I knew there were problems with the HP 520, at least with this model of HP 520. This HP 520 is equipped with Intel Core 2 T5200 CPU, according to wikipedia(http://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors), it looks like this CPU is an OEM product. It’s a Core Duo 2 CPU, but it can’t run 64bit OS, and no hardware virtualization support either, really weird. Anyway I can’t get it work with VMware ESXi, a little frustrated,  I have to use KVM VMs for testing krugle before the new server reaches.

Gnome-do 0.8.1.3 doesn’t show application items

Gnome-do 0.8.1.3 doesn’t show application items on my Gentoo/Gnome 2.26, but 0.8.0 does, the following screenshot shows 0.8.0 is listing “Terminal” related items when I type “ter” in gnome-do, and the first one is the one I want: Gnome Terminal: gnome-do The problem with my gnome-do 0.8.1.3 is: it doesn’t list anything of my application items(The ones sits in Gnome’s Applications menu), I think this functionality is of gnome-do itself. But all the plugins of gnome-do work well, it’s really weird why it breaks while 0.8.0 worked for me.

Window doesn’t redraw correctly when using compiz

Window doesn’t redraw correctly sometimes when using compiz, but if I switch to another window then switch back, it redraws, this problem occurs with any type of windows, it’s annoying.

I am using compiz 0.8.2 on my DELL 1420, with a Nvidia 8400M GS video card and Nvidia driver of version 180.44.  Once upon a time, I can run compiz on this computer without any problem, but that’s really a very long time ago, with a very old nvidia driver and very old compiz fusion.

After looking around the web, I found there are people with the very same problem  as mine, some of them have same video card as mine too, and there are several solutions to this problem, but maybe one of the methods can solve one guy’s problem, but it doesn’t matter to other people, I have tried some of them, but none of them matters, following are some methods maybe useful(at least useful for some people to get this problem solved):

  1. Use “Indirect Rendering” option to start compiz
  2. Use “Loosing Binding” option
  3. Put in ~/.gnomerc this line : dia-settings -a InitialPixmapPlacement=1 -a GlyphCache=1
  4. The problem is caused by an Nvidia feature called “powermizer” that pushes the video card into low performance mode, so load nvidia kernel module with these parameters:
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options nvidia NVreg_RegistryDwords="PerfLevelSrc=0x2222"
options nvidia NVreg_Mobile=1

I’ll try these solutions one by one, and maybe combination of these solutions, hope this annoying problem can be fixed.

UPDATE: It looks like the problem has gone after I enabled “Indirect Rendering” and “Loosing Binding” at the same time, wow!

Unmount the unreachable NFS volume

I previously mounted one NFS volume from the NFS server, but now the NFS server is down, then I have problem with “df” command to see the disk space usage information from my computer, now the only thing I want to do is to unmount the unreachable NFS volume.

The NFS volume is mounted at /mnt/nfs, when I try to unmount the NFS volume, I am told that it is busy, so I use lsof /mnt/nfs to find out the process using it normally, but lsof gets stuck and it never return the shell prompt to me. Ok, then I use fuser -9 -k /mnt/nfs, try to kill the process forcefully, but fuser gets stuck too…

All methods I normally use to unmount a volume fail, so I go back to RTFM, and I get two interesting options of umount:

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-f     Force unmount (in case of an unreachable NFS system).  (Requires
       kernel 2.1.116 or later.)

Good, it looks like what I need, but unfortunely I fail with umount -f /mnt/nfs all the same, so I move on to another option:

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-l     Lazy unmount. Detach the filesystem from the filesystem  hierar‐
       chy now, and cleanup all references to the filesystem as soon as
       it is not busy anymore.  (Requires kernel 2.4.11 or later.)

Wow! It works like a charm! That’s it: “umount -l /mnt/nfs”, maybe it will never be a pain to face a unreachable NFS volume again.