[mythtv-users] Maintain Mythtv Uptime using Virtual Machine; Possible?

lists_mythtv_users lists_mythtv_users at bigpizza.co.uk
Thu Jul 17 19:47:00 UTC 2008


Gordon McLellan wrote:
> Steve:
>
> I had (still have actually) a tunerless mythtv master-backend server
> running as a Xen virtual machine (pvm), and nothing special was done
> during the install.  The guest OS is Centos 5.2, and I'm using myth
> from the atrpms repository.  That myth setup is no longer active, but
> I have the server running still so I can access the recorded shows.
>
> Network filesystem issues caused me to abandon this setup ... I was
> running the tunerless master backend, and a slave backend + frontend
> remotely over a gigabit link.  The slave machine didn't have the
> stones to handle gigabit network IO and manage the dual tuner pvr-500
> card - the time kept getting messed up, to the point I was running
> ntpdate every 15 min via cron to make sure my recordings were more or
> less on time.
I recently spent some time investigating a problem I had on a Windows 
2003 R2 server running under VMware server 1.04 on my OpenSUSE 10.3 
box.  I found that the problem was due to Intel Speedstep being enabled 
on the motherboard.  This caused the CPU clock to vary between 1.6GHz 
and 2.4GHz depending on the CPU load.  Once I'd turned off Speedstep in 
the BIOS the time in the Windows guest ran perfectly.  This may or may 
not apply to a DomU running under Xen but I've read that a varying clock 
speed on the host is a difficult problem to deal with under any 
virtualisation system.

As an aside, I spent some time trying to get Myth working under Xen but 
I couldn't pass the DVB cards through to the DomU reliably, any attempt 
to scan for channels would result in the DomU hanging.  This was some 
time ago under Xen 3.0.4 IIRC so things may have changed since then, I 
believe VT-d support is much improved now.

Thanks for the info.  I'll give the VM route a try and see how things 
turn out.

Steve.



More information about the mythtv-users mailing list