[K12OSN] OT: still have sluggish system

Fri Sep 8 02:05:57 UTC 2006

David,

On my opteron system, still have the nscd issue.  Also, we have students logging on/off alot.  Without nscd it just becomes a real nightmare.  Of course, currently I can't tell the difference.

I can try a boot with the options you mention, but the console seems fine.  As for video/sound, I haven't gotten far enough to even have those issues.  Sounds works (first person only though, known issue, resolved with latest ltsp patches),  not sure if sound/video will stay synced up. 

<begin whining>
The support for usb devices and sound are the entire reason we upgraded to this version -- we have 4 teachers that are vocally demanding that sound/video work or else it is back to Windows.  Have a couple of weeks to get it fixed and then this issue crops up.
<end whining>

Anyhow, the latest was that around 3pm thin clients just quit booting from the system with the NFS mount issue.  tftp et.al. were running, so I rebooted the box and everything came back up.  Tomorrow (Friday) I will start using ntop/sar/tcpdump to see if I can get some kind of handle on what the real issue is.  Of course I only have a couple of hours in the morning before I have to be at another school to assist with some work there.

Ran dmesg and nothing jumped out at me.  All the hardware was recognized, no warnings/issues.

Thanks though for the suggestion, I will see if the tech teacher is up to an experiment with it.

Sincerely,
Dave Hopkins

 -------------- Original message ----------------------
From: "David Trask" <dtrask at vcsvikings.org>
> There was an nscd bug that caused it to die....I'm not sure if it got
> fixed....I suspect it did.  When it happened though I found that turning
> off nscd solved the issue...and we've also found that unless you have a
> LOT of users, it's unnecessary.  also...as for the slow server...I had one
> with a hardware conflict that suddenly cropped up in FC4 (previous
> versions were fine) I had to add "noapic" and "noapci" to the grub file
> menu.lst to get it to run right.  In FC5 the problem seems to be better,
> but not solved....so I just got a new server yesterday just like the one
> that I'm NOT having hardware issues with (made sure)....so I am
> "reprovisioning" it....the new server becomes the K12LTSP box and the
> older one becomes the Windows Terminal server.  LOL   Anyway....are you
> experiencing things like sluggish video....slow dialog boxes...and so
> forth even when actually on the server?  If so it could be a hardware
> conflict.
> 
> 
> "Support list for open source software in schools." <k12osn at redhat.com>
> writes:
> >> 
> >> The high bandwidth usage is an obvious candidate. Any idea on what is
> >> chewing up the bandwidth?
> >
> >Not really, usage patterns/programs for the teachers/students haven't
> >changed much year-to-year.  Software packages are the same as last year. 
> >Only change was FC5 upgrade. (mb is Supermicro X5DP8-G2 in case that
> >matters somehow)
> >
> >> 
> >> I would also check for authentication/authorization issues (I note in
> >> the archives that you use LDAP).
> >
> >Yep, used David Trask's instructions originally, updated with Matt's
> >script later.  Nothing changed though in last year.
> >
> >> 
> >>   Double-check that all of the LDAP configs are correct.
> >> 
> >
> >Everything is as it should be.  Haven't upgraded to latest samba though
> >because of concerns with the latest/greatest version of samba and the
> >traffic on the samba list about it.
> >
> >>   Make sure that nscd is running (/sbin/service nscd status)
> >> 
> >
> >Have had an ongoing issue with nscd since like forever.  I am using a
> >dual-Opteron server with the prior version of K12LTSP running (x86_64). 
> >Fully patched, but I have not upgraded the system to the FC5 version. 
> >nscd still dies 2-3 times each day.  A simple restart, or at worse clear
> >the database files and restart resolves the issue (on site tech teacher
> >has a script that he runs if he sees the authentication stop). I am
> >planning to move my LDAP server to a new 32-bit system just to get away
> >from this issue.
> >
> >>   Make sure that DNS is correct (/etc/resolv.conf)
> >> 
> >
> >Haven't touched this either, but will recheck.
> >
> >> 
> >> I'd also check the disk sub-system...
> >
> >I did upgrade from Ultra160 IBM Deathstar drives (they were dirt cheap
> >and now I know why) to Ultra320 Seagate Barracuda's.  Was using a
> >zero-channel controller for RAID-1 on the OS drives, but ... that is
> >another thread. :)  Now using software RAID-1 on one system, nothing on
> >the other (skating on thin ice).  Both systems show the same issues.
> >
> >> 
> >>   Run "dmesg" and look for SCSI errors
> >> 
> >Haven't seen any so far.  Checked earlier, will check again.
> >
> >>   Run "sar -b" to see the disk I/O usage patterns
> >>   (if you don't have "sar", install it with "yum install sysstat")
> >> 
> >have to install and test this as well.  Only issue is that I am running
> >out of annual leave to spend at the school troubleshooting this.  The
> >issues only show up under load.  Still, will be there tomorrow morning
> >bright and early since it is my day off :)
> >
> >Sincerely, and thankfully,
> >Dave ...
> >
> >_______________________________________________
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> >K12OSN at redhat.com
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> 
> 
> 
> David N. Trask
> Technology Teacher/Director
> Vassalboro Community School
> dtrask at vcsvikings.org
> (207)923-3100
> 
> 
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