I would like to see Linode integrate the ztdummy driver into at least one of the Linode 2.6.x kernels. The dummy device does not take that many resources (it is just an overlay of 2.6.0's high resolution timer system) and is of great benefit to people who want to use Linode as an Asterisk VoIP server system (some useful applications like MeetMe conference bridge refuse to work without a timer). More information on Asterisk timing and dummy kernel devices can be found at http://www.voip-info.org/wiki/view/Asterisk+timer.

Happy holidays!

hear, hear!

I had an e-mail discussion with Digium about adding support for building the ztdummy module into the kernel so that it could be built to meat Linode's Security guidelines. They said that the UML enviroment does not provide reliable enough timing for the driver to work.

When Linode moves to Xen then we will be able to build our own kernels and also have module support. Xen also has better timer replication so ztdummy should work.

Shawn

So when will Linode move to Xen? I need ztdummy too.

isnt there a xen test server (or a few) that u can be moved onto? Perhaps raise a support ticket and ask?

There is a Xen test server - but you don't get to build your own kernels.

_________________
/ Peter

Now that Linode is on Xen, can we please please please get the ztdummy kernel module installed on the hosts?

the xen kernels now support module loading. kernel source is available here:

http://linode.com/src/

So, for example, how would I load the ztdummy module? Just compile it against the kernel sources/headers and insmod as usual? That didn't work when I tried it.

error messages? kernel version? did you compile it against the correct source?

"it don't work" really isn't much help.

also, from insmod(8):

DESCRIPTION
       insmod  is  a  trivial program to insert a module into the kernel: if the filename is a hyphen, the
       module is taken from standard input. Most users will want to  use  modprobe(8)  instead,  which  is
       cleverer.

You're being a bit disrespectful, but I'll indulge you: I compiled zaptel 1.4.9.2 against the domU-linode7 kernel sources.

I used insmod because I was specifically pointing to a .ko file (the module itself), not its alias or expandable name in some search path, because I suspected that modprobe wasn't doing its job. The symptoms were basically that I got no errors and the module seemed to load (according to dmesg), but did not show up in lsmod and asterisk couldn't see it according to its logs.

How'd you get it to work?

ido, give ztxen a shot, you should have much better luck with it. http://bugs.digium.com/view.php?id=9592

ztdummy requires access to the RTC clock which the Xen guests do not have access too, ztxen removes this requirement using kernel interrupts as a replacement timing source.

Mike

Thanks Mike!

I am done installing asterisk on my vps but when the vps restarts it will indicate that zaptel failure. I don't know how to compile and install linode zaptel. can any one instruct step by step please......
thanks

// Please note I don't use Asterisk nor have I ever tried. This is just from a simple google search [1] & [2] and my knowledge of *nix. I, assume, you know what you are doing and can modify my guide to your needs, as well, I hold no responsibility to you messing your system up.
// Helpful links
// Source 1: http://www.voip-info.org/wiki/viewAster ... stallation (shameless guide)
// Source 2: www.linode.com/src/ (Linode Kernel source files)
// Source 3: http://www.voip-info.org/wiki/view/Aste ... aptel.conf (configuring you .conf for zaptel)


I don't have a guide on hand for compiling a kernel for linode. This will be needed.

To compile the module:

cd /usr/src
svn co http://svn.digium.com/svn/zaptel/branches/1.4 zaptel 
$: ./configure && make 
# make install

modprobe zaptel 

Add the module to /etc/modprobe.conf

// the $ denotes normal user (although root can be used)
// the # sound in front denotes (root or sudo)

Debian:

apt-get install zaptel-source
m-a a-i zaptel
/etc/init.d/zaptel start