[mythtv-users] Question re: available SATA ports and linux software RAID

[John Drescher]

On Fri, Apr 8, 2011 at 11:31 AM, Alex Butcher <mythlist at assursys.co.uk> wrote:
> On Fri, 8 Apr 2011, freedenizen wrote:
>
>> On Fri, Apr 8, 2011 at 8:04 AM, Tyler T <tylernt at gmail.com> wrote:
>>
>>> Just FYI, Linux mdadm software will RAID partitions just as well as disks
>>> (which I have done myself with success on more than one machine). For
>>> example, you could make a small OS partition and large recordings partition
>>> on each of your 2TB drives. Then you can RAID-1 the OS partitions and RAID-6
>>> the recordings partitions.
>>
>> The problem is that you are using the same spindle for your OS (and
>> presumably your DB) and recordings.  That configuration can cause
>> performance issues.
>
> Never has for me, in five years of running MythTV, on everything from a
> Celeron 1.7G to my current i5-760.  Even my recent ionice stuff was
> pre-emptive, rather than reactive (with the exception of the ionice'ing in
> mythburn.py).
>

Even if it does you can probably tune mdadm to reduce the impact of
the database. Look into increasing stripe_cache_size.
-- 
John M. Drescher