[mythtv-users] Planning Tuners and Disk I/O for a MythTVBackend System

[Travis Tabbal]

>
>
> Will the new sda1 partition be large enough, or is 60GB too big?
>


What's it for? The OS/DB? If so, drop it and put the OS/DB on a different
drive. An old IDE drive will work fine, SSD if you really want performance.
I used an old 40GB IDE drive from an old TiVo, it worked great. With 12
tuners you might want something a little more speedy for the DB though.

Sharing the OS and DB with the recordings is a recipe for lots of seeks,
hosing your I/O speed. Put your swap on the OS drive as well. For the size
of the system you're talking about, the disks holding recordings should hold
ONLY recordings. I'd partition them into a single partition with XFS. Don't
share spindles, it's not worth it. Why the live TV partition? Just let Myth
balance the I/O by putting the whole-drives in the same storage group. If
you find your I/O system can't keep up, add more disks to the storage group.
For this reason, unless you need huge space, I'd buy 500G or smaller drives
and just use more of them. If you can't fit more disks in there, time to set
up a dedicated backend box.


I see XFS, and EXT4, talked about a lot for large file types. Which of
> these, or possibly another, would be the best choice for the recordings
> directory?
>


EXT4 does pretty well with large files, but I still like XFS for recordings.
Set the pre-allocation size up around 500M and you will keep fragmentation
low. Again, keeps seeking down.



> I'm thinking FAT32 on the USB drive for portability, if I ever want to
> mount it temporarily on another system. Shouldn't be a problem for MythTV,
> should it?
>


It will work, but be more fragile. Back up the data somewhere just in case.
Which you should be doing anyway.



> Lastly, I have 2GB of RAM installed in this system, should I even bother
> with the swap partition?



My backend has 2GB and rarely uses any swap. It's also running other
processes. So you might be able to get away without swap, I generally put it
in anyway though. If a process needs to use it, it generally doesn't just it
long.
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