[mythtv-users] Network Drive Storage Questions and others.

Stuart Larson halcyon at obfus.com
Sun Sep 17 16:24:28 UTC 2006

> All,
>      So i've had my MythTV setup now for about 6 months and loving it to
> death.  Wife's happy, i'm happy, it's all good.
> Big problem is I went with a 250g disk for /video, which I knew at the
> time
> was small.  Amazingly enough (NOT) it's full...gee, couldn't have guessed
> that would happen.
> So, starting to look at a new drive but also starting to re-consider the
> whole structure.
> Currenlty I have a frontend/backend on one computer with the drive
> internal.  Works as a basic Myth box, no questions about that.  I'm
> starting
> to try to figure out about client / server installs and off computer disk
> storage.
> Networked disk storage: Considering building or having a computer who's
> use
> is network disk storage.  What i've got right now is IDE (unfortunately
> it's
> not sata but money doesn't grow on trees and a new computer right now is
> kinda out of the question).  I can go up to 4 disks on the controller i've
> got right now (it's a raid controller).  Is IDE going to cut it across a
> network?  Will a PII 400 cut it for a disk array device for harddrive
> storage of Myth Videos (Don't see why not).  Figuring exports via both
> Samba
> and NFS...nfs exporting the drive area SHOULD get mytharchiver to make it
> think the files are local.  Is 100 Base T going to do it for streaming the
> myth recordings out to a foreign disk or do I need to go with gigabit?
> (Yes,
> it's wired)

Keep in mind you have to keep all recordings in one place (well, one
directory).  I currently use a LVM in my backend with three disks, but
those drives could be anywhere, really - nfs exported to the backend would
be fine.  100bT is fine, too - depends on how much you're recording at
once, I suppose.  Currently I run a frontend over wireless (802.11g, so no
delays or skips), so 100bT should be plenty.   This is only for standard
def though, high def would definately need at least the 100bT

> Opinoin question: If you were going to build a network drive array right
> now
> how would you do it?  Stay away from SCSI, I don't think I could afford to
> go there.

I don't have a file server, per se, but RAID or LVM should do it - also
keep in mind that you're only going to be transfering data as fast as your
network can go, so the type of interface isn't THAT important, but maybe
reliability would be more important.  I'd probably throw a lot of drives,
on whatever interface I could get into the box, into a LVM and then nfs
export it... but it wouldn't be very fault tollerant.

> Frontend/Backend: Don't quite have the computer for this yet don't think
> but
> in the future, what kind of horsepower does the front end / back end need?
> Do they both need 3g+ CPUs or does one or the other only need something
> significantly slower?

Are you doing any Highdef?  If so, you'd need faster computers, or a card
that can do XvMC and a moderately fast computer for playback.  Standard
def (I'm assuming you're recording standard def, and with something like a
PVR-x50) doesn't need much at all to record OR play.  If you're doing
software encoding (like a BTTV card), then you may need a bit more CPU (I
got away with a BTTV card in a 800Mhz celeron or something PC... but I
couldn't watch and record at the same time).  With a hardware capture
card, you don't need much in the backend at all - you're only really
transferring up to 12Mbit/sec for standard def (that's at highest bitrate
settings), which even a slow computer should be able to handle.

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