[mythtvnz] New list member - Hardware recommendations

[Nick Rout]

On Sat, Jan 14, 2012 at 9:01 AM, criggie <criggie at criggie.org.nz> wrote:
> On 13/01/12 22:57, Steve Hodge wrote:
>> On Fri, Jan 13, 2012 at 19:01, criggie <criggie at criggie.org.nz
>> <mailto:criggie at criggie.org.nz>> wrote:
>>     My sql database is 335 MB, so it might be feasible to make a raid1 with
>>     a partition and a ramdisk.  In theory the writes complete when one disk
>>     is written, so that would be the ramdrive.  And the data on the hard
>>     drive would provide the permanent storage over a restart.
>
>> With RAID1 a write does not complete until all copies have been written.
>> So write performance is approximately equal to the slowest disk in the
>> array. The setup you're describing would act more like a cache except
>> typically RAID implementations are not designed with radically different
>> performance of component drives in mind so you might not get the read
>> speeds you're expecting either as at best reads would probably be split
>> evenly between the ramdrive and the physical disk.
>
> Again you're right - I must have been remembering something from the
> docs on a hardware raid controller's cache settings that allowed the
> write to "complete" from the OS's point of view.

On this general subject there are some useful comments in this thread:

http://www.gossamer-threads.com/lists/mythtv/users/500144#500144