[K12OSN] CentOS + USB devices

Fri May 30 12:16:36 UTC 2008

I use the CentOS 5 EL version of K12LTSP. I also have devices set up  
for locally attached printers. In one location I have every thin  
client setup with the parallel port mapping to 9100 and usb to 9101  
respectively. (not a great option but the site randomly replaced  
printers and I was tired of modifying lts.conf). I also do not have  
any issues. However I also run 100+ CentOS machines using cups. I  
recently ran into an issue where I was not able to print. The problem  
turned out to be DNS related. I have found that if you can not resolve  
a host using both forward and reverse lookups, CUPS would not always  
print (it was intermittent).

Make sure
host 192.168.0.100
  returns pc100.foo.bar.com

host pc100.foo.bar.com
  returns 192.168.0.100

Hope that helps

Lewis

On May 27, 2008, at 11:41 AM, Marc Fromm wrote:

> On our working LTSP server the entry use-host-decl-names is commented
> out in the dhcpd.conf file. I uncommented the entry on the LTSP server
> that is not printing and set it to on. I then restarted dhcpd and  
> cups,
> but printing still does not work to a locally attached printer.
>
> -----Original Message-----
> From: k12osn-bounces at redhat.com [mailto:k12osn-bounces at redhat.com] On
> Behalf Of Rob Owens
> Sent: Friday, May 23, 2008 3:50 AM
> To: Support list for open source software in schools.
> Subject: Re: [K12OSN] CentOS + USB devices
>
> On my system, I needed to set:
>
> use-host-decl-names on;
>
> in dhcpd.conf for the section where the printer-attached workstations
> reside.  Give that a try and restart dhcp.
>
> -Rob
>
> Marc Fromm wrote:
>> All my systems have a DHCP reservation, as listed in the example
> below.
>> My setup is a frsh install of the latest K12LTSP CentOS 5 EL.
>> Was there something to select during the install?
>> vi dhcpd-k12ltsp.conf
>> host finaid70 {
>>                hardware ethernet 00:B0:D0:C3:0C:A6;
>>                fixed-address 140.160.xxx.xxx;
>>                filename "/lts/pxe/pxelinux.0";
>>        }
>>
>> -----Original Message-----
>> From: k12osn-bounces at redhat.com [mailto:k12osn-bounces at redhat.com] On
>> Behalf Of David Hopkins
>> Sent: Thursday, May 22, 2008 12:03 PM
>> To: Support list for open source software in schools.
>> Subject: Re: [K12OSN] CentOS + USB devices
>>
>> On Thu, May 22, 2008 at 2:17 PM, Marc Fromm <Marc.Fromm at wwu.edu>
> wrote:
>>> I'm setting up a new k12ltsp server. Our current server (not setup  
>>> by
>>> me) has USB printer directly attached to a client and it is setup in
>>> CUPS using Device URI socket://finaid76:9100 since that client is
>> always
>>> logged on with user account finaid76.
>>>
>>> The lts.conf file has an entry
>>> [finaid76]
>>>       PRINTER_0_DEVICE        =/dev/usb/lp0
>>>       PRINTER_0_TYPE          = U
>>>
>>> Since there are no clear instructions with printers I am duplicating
>>> configurations that currently work.
>>
>> Ah ... a beginning point for printers is
>> http://www.ltsp.org/twiki/bin/view/Ltsp/Printers
>>
>> The 'trick' is that you need to add a DHCP reservation for each thin
>> client that will have a printer attached to ensure that the thin
>> client always has the same IP address and hostname.
>>
>>> For USB thumb drives, what is the Fuse group?
>>
>> In looking at the latest docs for ltsp on ltsp.org's wiki, it seems
>> that this might not be needed.  but for my systems, I had to create a
>> user group called fuse and add all my users to it so that the drives
>> were automounted correctly. Since it worked, I've kept adding users  
>> to
>> this group.
>>
>> Fuse should be part of the main kernel now, but if not CentOS should
>> be similar to
>>
> http://www.ltsp.org/twiki/bin/view/Ltsp/LtspFS#Installing_FUSE_on_Fedora
>> _Core
>>
>> Sincerely,
>> Dave Hopkins
>>
>>> -----Original Message-----
>>> From: k12osn-bounces at redhat.com [mailto:k12osn-bounces at redhat.com]  
>>> On
>>> Behalf Of David Hopkins
>>> Sent: Thursday, May 22, 2008 11:07 AM
>>> To: Support list for open source software in schools.
>>> Subject: Re: [K12OSN] CentOS + USB devices
>>>
>>>> Are the usb ports disabled on the client machines in k12ltsp  
>>>> CentOS?
>>>> I have plugged in a usb thumb drive and a printer into a client and
>>>> neither are detected. I plugged the same usb thumb drive into the
>>> server
>>>> box and it was detected.
>>>>
>>> They work for me, but users need to be in the Fuse group.
>>>
>>>> I added the printer using the CUPS web interface localhots:631.
>>>> I used Device URI: socket://finaid70:9100
>>> Is this correct? Isn't it socket://IP_address_thin_client:9100 or
>>> socket://hostname_of_thin_client:9100 (which are typically
> 192.168.x.y
>>> and ws###.ltsp for the base install).  We have 80+ printers  
>>> connected
>>> to thin clients and they work fine but we are using the parallel  
>>> port
>>> for the printers, not the usb port.
>>>
>>> Sincerely,
>>> Dave Hopkins
>>>
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>>
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