[mythtv-users] Linux software raid question

[Yan-Fa Li]

On Tue, Jun 3, 2008 at 9:10 AM, James Klaas
<jklaas at appalachian.dyndns.org> wrote:
> On Tue, Jun 3, 2008 at 11:34 AM, Matt Nelson <matt at frozenatom.com> wrote:
>> On one of my mythtv backend servers I host my fileserver that stores all of
>> my media on two raid5 sets totaling 12 drives that are all attached via
>> sata.  These are all attached externally, and that is where my question
>> lies, if I connect these drives incorrectly will my raid sets die, or does
>> it not matter where they are connected since there is some metadata that
>> tells the linux software raid that it belongs to a certain raid set?
>>
>>
>> Also since I love seeing how people are setting up their mythboxes, attached
>> is a picture of the back of the myth backend server mentioned above.
>>
>> http://img115.imageshack.us/my.php?image=05310720471ot5.jpg
>
> Did you consider using a SATA port multiplier
> (http://www.satadrives.com/saii1to5popo.html)?  I think these are
> pretty well supported by recent kernels, although I'm not sure how
> well they're supported by non-SiliconImage chipsets.  Does anyone have
> an opinion on those?
>
> James

I'm about to try something like that out in the next couple of weeks.
I have a sil 3124 based controller on it's way to see if it's
compatible with my file server PCI-X implementation and then I've been
looking at these:

http://addonics.com/products/host_controller/extpm.asp

According to the research I've done at http://linux-ata.org/ support
for both the 3124 and the 3726 PMP is good as of kernel 2.6.25, which
is bleeding edge and beyond most mainstream distributions, but I'm on
gentoo so it's not really an issue.  Using this sort of solution it's
possible to get to 20 ports of eSATA which should scale for quite some
time; 18TB RAID6 array anyone?  Then your problem becomes finding a
filesystem that will scale to that.  Though with mythtv that's no
longer an issue thanks to storage groups assuming you can stand losing
some TV.