[mythtv-users] how much is enough -- configuring a server

Mark J. Small msmall at eastlink.ca
Thu Nov 15 14:50:33 UTC 2007


On November 15, 2007, Tom Dexter wrote:
> On Nov 15, 2007 5:39 AM, Mark Small <msmall at eastlink.ca> wrote:
> > In such a system, your biggest bottleneck will likely be bandwidth to the
> > hard disk(s).  If you've got 4 folks watching HDTV streams, that's a TON
> > of data the gets written and read constantly.  Some sort of RAID setup,
> > or 1 or more slave backends may be necessary.
> >
> > Thy only reason to have a beefy CPU for your setup is transcoding to
> > mpeg4 to reduce file size.
> >
> > Mark
>
> I suppose he might...it's hard to say.  I have only one frontend with
> three HD-5500 cards in the backend.  I'm able to record three HD shows
> at once while watching a fourth previously recorded show from the
> frontend...that's a lot of IO.  My backend is a Dell 4600 with two 500
> GB Seagate IDE drivers simply using a big vdeo LVW2 volume...and that
> actually means the OS partition and even the database is on the same
> physical drive as part of that LVM volume...which certainly isn't
> ideal.  I've never had any noticeable issues.  I'm using ext3, so I
> had to turn on slow deletes.
>
> Of course with four cards there's a potential for five programs being
> written and/or accessed at once...that could be pushing it.
>
>  As far as CPU, I've checked it out while recording three shows and
> watching a recording, and the backend is generally as 1-2%...pretty
> much asleep.
>
> Tom
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users

I'm not saying that it will be a problem, but when he mentioned 4 frontends 
watching Live HDTV, meaning 4 huge reads + 4 huge writes, the alarms bells 
went off that there might be an issue.  I think there are folks that have bug 
setups like this around.  Maybe they will chime in.

My 3 tuner SD backend has no issues with three tuners go full tilt + some 
playback using a single recording hard drive.  But SD is much smaller than 
HD.  

Mark


More information about the mythtv-users mailing list