[mythtv-users] large mythtv deployment

[Jake Anderson]

Steve Heistand wrote:
> } We hope to have 6 feeds at 1080i and 2 at 720p. Do we even have enough
> } computing power to do this?
>
> if you are just recording the streams and not transcoding them then
> its just 8 simultanious writes to the disks. not much cpu power required.
> lots of disk accessing though. but any good raid should be fine.
>
>
>   
Don't use RAID, disk seeking will kill you.
Stick a bunch of disks into your backend and set them up as storage groups.
The disks will just be ticking over with each disk storing one stream or 
2 rather than thrashing all over the place to write a teensy chunk of 
data here and there.

Look at using XFS for the file system and then tell it to allocate in 
large blocks as its writing (like 128mb or so)
(its an XFS option not the actual blocksize that large, when you start 
to write a file it then assumes that the file is going to be at least 
that big, if you have 2 streams going on to one disk it reduces 
fragmentation a fair bit.)

Will you be commercial flagging this stuff? If so bank on one cpu core 
of a core2 style CPU per stream to do it in real time.