[mythtv-users] Some master/slave backend advise required

[Hika van den Hoven]

Hoi Johan,

Monday, June 2, 2014, 8:59:49 PM, you wrote:

> Hi,

> I’m running myth 0.27 (v0.27.1-7-g41d04b6) on Ubuntu server 14.04
> with an i5(3GHz) and 4GB memory. I’m using 4 DVB-S2 tuners as source.
> Due to relocation of the dish I have to install a slave backend. I
> can’t (don’t want to) move my server to the garden shed.

> I have found that recording about 8-10 HD channels simultaneously
> will start killing processes on the backend (not the myth processes
> though), but the CPU load of the DVB-s2 stuff by itself requires
> 100% cpu. Mythcommflagging did not help either, although I could
> limit the simultaneous jobs to get more breathing space. 
> So my thought was to solve both problems at the same time with a
> new slave backend, where the dvb-s2 stuff is running, by itself.
> Storage and commflagging still to be done on the master backend (which has 8TB of ZFS storage)

> I can see two issues now:
> Bandwidth: When recording 10 channels (what I want to achieve), I
> estimate worst case (based on what i recorded so far) 3GB per
> channel per hour, or 833Mb/s one way traffic, without other
> overhead. And not watching anything...
> How to solve this, and does myth traffic between master and slave
> benefit from Jumbo Frames. I could use two network cards in each
> machine, and create a 2 x1 Gb trunk between the switches.
> Second part of the problem might be that the ZFS file storage is
> not fast enough. (upgrade to SSD maybe)

> Configuration:
> Is it possible to configure mythtv in such a way that it does what
> I want, or are there better ways to do this? 

> Any help appreciated!

> Johan

I would always keep recording and storage on the same machine. You
could move the database, commflagging, metadatalookup etc to a slave.
Alternatively you could split up your recorders and the storage space
over both machines.


Tot mails,
  Hika                            mailto:hikavdh at gmail.com

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