[mythtv-users] thoughts on a combined backend/NAS box?

[Joseph Fry]

On Tue, Jul 16, 2013 at 1:55 AM, GZ <gzornetzer.lists at gmail.com> wrote:

> Hi all,
> I've been thinking about upgrading my mythtv setup and at the same time,
> I've also been looking at buying a RAID5 NAS box.  After looking at the
> price tags on some of those enclosures, I'm thinking about just building a
> combination RAID / mythbackend box.  I've read some of the guidance on the
> wiki, indicating that RAID really isn't the best way to go for the mythtv
> recording drive.  I'm thinking about the following drive setup:
>
> 1 SSD for the OS/database
> 1x 1 tb for active recording (my existing recordings drive.  Eventually, I
> may just upgrade this to a 3tb drive that would act something like an
> in-use hot spare
> 4x 3tb drives in RAID5 for archive storage (pictures / long-term video
> archive)
>

If you buy a large SSD for the OS/database you could use it as your
recording drive and dump the recordings to the raid array after X days
using a cron job.  A decent SSD will easily support several simultaneous
recordings, playback, and comflagging jobs.


>
> Since all of my tuners are now external (HDHR prime & usb QAM), I'm
> thinking about a microitx motherboard to keep this box smallish (corner of
> my office).  There are a few H77 boards with 6 total SATA ports an H87
> board with 6x 6gbps sata.  I figure that a 4-core ivy bridge or haswell
> process has plenty of juice for this.
>

Definitely enough juice.  Go Haswell if you can for the added power savings.


>
> Couple of things that I'd like to do:
> - It would be cool to move shows from the recording drive to the archive
> upon lossless transcode.  Do I have to write custom transcode rules to do
> this?
>

Pretty sure you do... but should be trivial.  One good thing about this
method is that you can schedule the transcode to happen X hours after
recording... so only shows that you don't watch and delete right away are
archived to the RAID.


>
> - I'd like to use ACPI wakeup to reduce power usage on this system.  This
> means that I'm going to need some way to lock mythbackend when I want to
> use the NAS functionality.  I suppose that I could run some mythfrontends
> on the client, but that's pretty kludgy.  How complex is it to code up a
> client that connects to mythbackend enough to bump the usage count and
> block shutdown?  Alternatively, does anyone have a good way to trigger a
> mythwelcome lock and unlock commands remotely over the network?
>

I don't think I would put my backend to sleep if it were also providing
other services.  You can try and get the drives to spin down for some power
savings (especially if your using an SSD recording drive).  I would imagine
that with spun down HDDs, a Haswell processor, a reasonable amount of RAM,
etc... you wouldn't be using more than 40W at idle.  I don't know what
power costs where you are, but it's probably not a significant savings.


>
> Any advice or thoughts are welcomed.
> Thanks very much,
> -Greg
>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.mythtv.org/pipermail/mythtv-users/attachments/20130716/6abca000/attachment.html>