[mythtv-users] Basics of Mulit Drive, Partitioning, File Sytems

[Leighton Brough]

Jon Boehm wrote:
> Hi,
>
> Totally newbie here.  I'm starting a new Front & Back Myth Box.  I'm trying
> to install Ubuntu 6.1 and I'm confused on the partition setup phase.  Please
> point me to a faq or other thread if this has been covered before
>
> Here is my hardware:
> 500GB SATA 300MB/S
> 320GB SATA 300MB/S
> 250GB SATA 300MB/S
> 250GB Slave IDE
> 2G RAM -- relevant for the swap info
>
> I don't think I need any redundancy (RAID).  I'll used rsync to regularly
> back up the important config file once I'm happy.
>
> Where should I put the root file system (boot) for best drive thru put?
> Would it be best to put it on a drive that is less likely to have video
> media on it so that video and OS would not be contending for drive
> bandwidth?
>   

That sounds reasonable to me.

> I'm thinking a 10GB for the OS in a EXT3 file system. Right size and file
> system?
>   

EXT3 is working well for me for my OS partition. Currently my dedicated 
front and backend box is using under 4GB for the OS and applications. 
With as much disk as you have you might want to give yourself a bit more 
headroom than just 10GB. I haven't used Ubuntu, but depending on your 
distro, what you want to install and whether you want to do things like 
build a kernel from source you may find 10GB is not enough. I think 20GB 
would probably be plenty for most mythboxes, however.

> I'm thinking 3G swap.  The rule of thumb I heard was 1.5 x physical ram.
> For performance where should the swap go?
>   

I think the RAM x 1.5 or 2 rule for swap doesn't really apply here.

My box has 3 HD tuners. When recording and commercial flagging 3 shows 
while watching another the system needs very close to 1GB of RAM. I also 
have 2GB of RAM, and with this swap is never used. So you could probably 
get away with no swap at all. I have only one 512MB partition for this.

Performance-wise, swapping and myth are pretty much incompatible. If 
swapping is occurring, you can pretty much expect either bits missing 
from your recordings or dropped frames and pauses in the playback.

> All the rest??? XFS file system? Should I use LMV?  Is there stripping build
> into LMV?  I've heard that LMV is not as important these days because Myth
> can now store files at multiple mount points.  Can a recording span multiple
> mount points? 
>   
I've had excellent results with XFS, as have others on the list. It 
seems the consensus is that you should use either this or JFS. I haven't 
got any experience with LVM or multiple mount points for recordings.

Leighton