[SOLVED] Task bar disappears + no Alt-Tab function

[Myles]

Just recurred and I was once again in LO Writer trying to save a doc. Once again mgaapplet is there:

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Sep 16 18:16:39 Bilbo mgaapplet[2597]: Received SIGHUP (probably an upgrade has finished), restarting applet.
Sep 16 18:16:40 Bilbo kdm[809]: X server for display :0 terminated unexpectedly
Sep 16 18:16:40 Bilbo acpid: client 889[0:0] has disconnected
Sep 16 18:16:40 Bilbo acpid: client connected from 3967[0:0]
Sep 16 18:16:40 Bilbo acpid: 1 client rule loaded

So to install LXDE I just issue

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urpmi task-lxde

to install LXDE?

I have just uninstalled mgaonline and we'll see how it goes from here.

[doktor5000]

So to install LXDE I just issue

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urpmi task-lxde

to install LXDE?

Yep, exactly. Then logout and select LXDE as session at the login screen.

[Myles]

Okay, thatnks doktor, I have successfully installed LXDE and did a test logon and all is fine. But I have reverted to KDE without mgaonline appllet running to see if that is the cause. So, a question: I notice in the syslog that mgaapplet seems to issue the command

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urpmi.update --update

. I this a valid command, and if so, can I issue it to keep my system up to date manually - or do I have to issue the more general

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urpmi --update-all

is that the command?

[Garthhh]

I've had the same behavior on 2 different machines [HP dc 5000, 2.2ghz, 1g ram the, built in video]
both clean M2 installs [the latest one about a week ago]
always when using firefox
my solution has been to quit using FF

[Ken-Bergen]

Myles, your first command

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urpmi.update --update

only updates the database it installs nothing.
Your second command

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urpmi --update-all

unless it's something new does nothing.
The usual command to update from the CLI is

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urpmi --auto-update

which updates the database then lists all updates with a Y/n prompt.

[Myles]

Thanks for that Ken, I was going on my fallible memory about the second command.

Anyway, just recurred,so it isn't mgaapplet this time as I have uninstalled that, but once again, I was in LO Writer - which seems to happen a lot:

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Sep 21 18:36:48 Bilbo kdm[804]: X server for display :0 terminated unexpectedly
Sep 21 18:36:48 Bilbo acpid: client 893[0:0] has disconnected
Sep 21 18:36:48 Bilbo acpid: client connected from 17825[0:0]
Sep 21 18:36:48 Bilbo acpid: 1 client rule loaded

[Myles]

This has happened a couple of times since I un-installed mgaapplet

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Oct  2 16:30:03 Bilbo kdm[747]: X server for display :0 terminated unexpectedly
Oct  2 16:30:04 Bilbo acpid: client 10891[0:0] has disconnected
Oct  2 16:30:04 Bilbo acpid: client connected from 23926[0:0]
Oct  2 16:30:04 Bilbo acpid: 1 client rule loaded

both with the

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dm(747)

present.

So it seems that it is not related to mgaapplet, even though that used to show up regularly in the syslog right before the failure, so I'll go ahead and re-install it.

Next is to test LXDE and see if I get failures with that as someone said earlier that may help. I prefer using KDE and can put up with this on an occasional basis but I would just like to know what is/may be causing it!

[Myles]

Well, I was going to write an update to this the other day saying that this hasn't occurred for a few months it seems - but I held off because I somehow had a funny feeling if I did that it would recur.
And it has. I didn't even notice as I was plowing through a 38 page document in LO (which contains text and photos) and I think that I still had a PDF doc open in Okular which contains text and photos.
So it is still happening,and still seems to be involving LO and when I have documents open/saving etc. Hasn't happened in VLC since early on.
So stillno nearer the cause.

[Myles]

Just thought I'd update this. NO it hasn't gone away, and it continues to happen - most often when I am using Libre Office - in fact just about every single time it occurrs I am using LO. About a month ago I was using LO pretty intensely (Writer and Calc) over the period of a couple of weeks. This occurred several times over that period! In fact, in ONE SINGLE DAY, it occurred 8 times!!! As I have stated before, I can't believe that I am the only person affected by this. Anyway, I am about to get a completely new system (except for the monitor and maybe the mouse). So it will be interesting to see how things go on the new system, whether this problem manifests itself on that as well. Also it will be interesting to see how Mageia 3 fares on the new system.

[Myles]

Now that I have upgraded to Mageia #3, I'll see how this goes in the new version.

[isadora]

And?

[Myles]

isadora,
Sorry I had forgotten about this. This particular problem hasn't (as yet) recurred under #3. But I have been having lots of other problems with Mageia #3 since I installed upgraded (problems) did full install (problems) did full re-install (see my posts) I now power off my PC overnight to bypass the suspension problem I was having (to which no one replied).

I am about to pickup my new PC next week and see if any of these problems show up on that.

For now I will mark this solved.

[Myles]

Well I thought I had marked it solved! But lucky I didn't - it occurred again last night. When I replied to Isadora I had only been using my Mageia #3 system (after 2nd re-install) for about 2 weeks. Anyway I had been using LibreOffice Writer quite often since the re-install - LO seems to be the most prevalent culprit! Anyway, I had downloaded a .CSV file earlier in the evening. Later on, I re-opened this file and then selected to save as an .ODS file - BAM, Task bar gone! I think that this has somehow got something to do with my old nVidia card and the noveau driver. I am waiting on some responses to my questions about my new system and installing on an SSD ( "Re: [EXPLAINED] UEFI support in Mageia 3 (for my new PC) "), so I'll wait till I have that up and going with brand new stuff. I'll leave this [UNSOLVED] till testing on the new system.

[jiml8]

My experience with problems in KDE always comes down to one of two things: bugs in X, and memory problems. Because I build my own systems, and I tend to overclock them at least somewhat, I am always watching for irregular behavior. Presently, my Mageia 3 system is quite stable, though I did have to tweak a bit after a recent memory and mobo upgrade.

There is a memory leak in X that I have seen in both Mageia 2 and Mageia 3. I have been trying to track it down to determine what conditions cause it to manifest, but so far I have not succeeded. Of course, I have not really focused on doing this either. I keep thinking Flash is implicated, but sometimes I see the memory usage burgeon when Flash has not been used (at least...I don't THINK it has been used...with some websites it is hard to tell). I find when X gets to the point where it is occupying 500 Meg or so, KDE performance (and reliability) heads straight into the toilet. Restarting X cleans things up. I usually have to restart X about once a day, sometimes twice.

I have also found the NVidia driver from the NVidia website to be quite reliable, though I cannot prove that it is not involved in the X memory leak.

The symptoms you describe suggest - but by no means definitively suggest - that you have memory issues...either hardware timing/voltage or a chronic low memory condition. LibreOffice is pretty big; that it appears to be implicated could be suggestive.

I recommend you start monitoring your memory usage - and pay particular attention to X to see what it is doing. You might learn something useful.

Beyond that, if you keep a shell window open, when your taskbar crashes you can restore everything by entering the command "killall plasma-desktop" (without the quotes). This will kill the entire plasma portion of KDE, and KDE will then reload it, and you will have everything back. IF for some reason, KDE does NOT restart plasma-desktop within a few seconds, then entering the command "plasma-desktop &" will do it for you. Of course, after you do that if you close that shell window, plasma-desktop will promptly terminate.

If you do not have a shell window open and can't get one, you can do a ctrl-alt-F2 to get to the second console window, then login and execute the killall plasma-desktop, then issue the command "plasma-desktop :0 &" and that will restart plasma-desktop in your KDE session. You then do a ctrl-alt-F1 to get back to your KDE session. This is much quicker than logging out and back in.

[doktor5000]

FWIW, KDE is running stable here, for several weeks up to a month. But i've also got desktop effects disabled,
together with Akonadi, Nepomuk, Strigi and some other of that newish flashy stuff which i've got no use for.

[Myles]

Thanks for that great info Jim and doktor. I thought that I had disabled desktop effects - I just checked in MCC, okay - but then checked in System Settings and those were enabled, so I disabled them there. It well may be a memory issue as you surmise. On this old system I only have 3Gb of RAM. As I said above I have my brand new system but am waiting on some responses about how to partition the SSD correctly before installing Mageia #3. The new system has 8Gb of RAM and an up-to-date, brand new nVidia card so I will, once again, be able to use the nVidia proprietary driver (my old card on this old system isn't supported any more under the new nVidia driver included in Mageia # 3). I am really only a newbie (even though I've been using it for quite awhile) and don't really know much about the ins and outs of how Linux works, I just use it.

Anyway, so hopefully all will be well when I get my new system up and going with Mageia # 3.

[doktor5000]

KDE will also run fine on systems with only 1GB RAM and even below with some tuning, as decribed in https://wiki.mageia.org/en/Speeding_up_KDE
So that's not the problem per se. I'd say it's definitely the nouveau driver. Did you try already for some time with vesa?

[Myles]

doktor, regarding vesa driver - yes I did. I had to as part of trying to get a stable install of Mageia #3 (see my post "MGA3 Upg/Install System problems") that nobody responded to. For that issue I eventually re-installed a second time and have been using the noveau driver since. I still occasionally get the WTSOD (happened last night and the night before). So maybe it is as you and I suspect - something to do with the noveau driver. I have just been putting up with all these problems (including with Amarok dying heaps of times in the past week all of a sudden) because I want to get to using my new system and hopefully all these problems will be gone!

[jiml8]

Try going to the nvidia site and downloading/installing the correct driver. I would think you could do that with a legacy driver, though I do not know for certain. I do know they have the legacy drivers available.

[Myles]

Jim I have downloaded a driver but I am a bit hesitant to install it. I'll give it a go and see what happens. If I do install it I it will be easy to revert to noveau if need be.