show stopper for us: dev nbd0 clients locking up losing connection with server

[john]

Scott et al.

When I set the swap options you mentioned It hung worse than ever. I
wonder if the problem lies with swap. I have
512 Mb ram on the clients. Maybe I shouldn't be swapping at all?


Well I found two bug reports that might be relevant:

https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/136410

Oli works on this one last year.

https://bugs.launchpad.net/ubuntu/+source/ltsp/+bug/172459

John


On Mon, Sep 15, 2008 at 11:41 AM, john <lists.john at gmail.com> wrote:
> Hm,
>
> That seemed to make it worse. Scott or anybody, do we have any FAQ's
> about troubleshooting nbd problems.
>
> Are other folks having trouble with 8.04/NBD ?
>
> Thanks,
>
> John
>
> On Fri, Sep 12, 2008 at 1:45 PM, john <lists.john at gmail.com> wrote:
>> <snip>
>>>
>>> OK, first thing I'd do is add in say 256 megs of NBD swap (assuming you've got
>>> the disk space) with something like:
>>>
>>> NBD_SWAP=True
>>
>>
>> Ok, I assume the proper place for this is /var/lib/tftpboot/ltsp/i386/lts.conf
>>
>> I added the line you indicated. Now that file reads:
>>
>>
>> LDM_DIRECTX=True
>> NBD_SWAP=True
>>
>>
>>>
>>> and edit /etc/ltsp/nbdswapd.conf
>>>
>>> SIZE=256\
>>
>> Ok, there wasn't already an /etc/ltsp/nbdswapd.conf so I created one
>> and added the line you mentioned.
>>
>> my /etc/ltsp directory now has the following files in it.
>>
>> dhcpd.conf  nbdswapd.conf  syslogd
>>
>>
>> BTW, Where is the disk space being used? I assume this is on the
>> server? Could you explain this a little more fully?
>>
>>>
>>> Also, within the thin client chroot, when they freeze up, can you ctrl-alt-f1
>>> and get the login prompt?
>>
>> The clients are currently completely frozen. I can't get an alternate
>> tty, however I am game to try this out if I get one that
>> responds.
>>
>>  If so, here might be an interesting test:
>>>
>>>
>>> Set a root passwd in the chroot:
>>>
>>> chroot /opt/ltsp/i386
>>> passwd
>>>
>>> Rebuild your image, then if you get a latch-up, c-a-f1 to the text login, go in
>>> as root, and use the free command to see if you've run out of ram, and run
>>> dmesg to see what the client thinks is going on.
>>>
>>
>>
>> Thanks!
>>
>> John
>>
>