[mythtv-users] RAID on Fedora Core 3?

[Max Waterman]

I am now thinking [1] of making do with 2x 2-channel PATA cards and
putting drives on as slave devices too.

If I make my 2 4-drive RAID 5 arrays like this


card 0 --- channel 0 --- master md0 #0
         |             |
         |              - slave  md1 #0
         |
         -- channel 1 --- master md0 #1
                       |
                        - slave  md1 #1

card 1 --- channel 0 --- master md0 #2
         |             |
         |              - slave  md1 #2
         |
         -- channel 1 --- master md0 #3
                       |
                        - slave  md1 #3

with one array's devices as master and the other array's device as slave.
My theory is, if I am fairly sure that I will only be accessing one array
at a time, then the devices will always have their own channel and performance
won't suffer.

However, I am lead to believe that slave devices work more slowly than master
devices. Is this correct?

Assuming I am correct, with RAID-0 this might work OK, since all the channels
are equal performance, but I am not sure of the load for RAID-5 - is the load
equal on all the devices in a RAID-5 array?

Max.

[1] I don't want to afford two 4 channel card at the moment - they're much
more expensive that the simple EIDE cards :( So, I think I'll try it this
way and see how it does - for now.

Peter Loron wrote:
> I don't have anything to say (+/-) about Highpoint, but 3ware makes 
> great hardware and they have excellent Linux support.
> 
> -Pete
> 
> On Dec 21, 2004, at 12:04 AM, Max Waterman wrote:
> 
>> While I am waiting for opinions, I am coming to the conclusion that 
>> Highpoint is a name to look for.
>>
>> Is this right?
>>
>> Max.
>>
>> Max Waterman wrote:
>>
>>> Hi,
>>>
>>> I am trying to build a MythTV/dvarchive box. I bought 4 Promise 
>>> Ultra100TX2 PCI cards, but found that they wouldn't work
>>> with more than 2 in a system :(
>>>
>>> I was going to use linux s/w raid over the drives.
>>>
>>> I know you guys must use plenty of raid setups, so thought you'd be 
>>> the best to advise on which types are best.
>>>
>>> I am running FC3, and have 4 WD800/8 and 4 WD2000/8 drives that I 
>>> want to be two RAID5 volumes. I am running
>>> on a nForce3 250Gb, so network traffic is not a problem with the PCI 
>>> bus, but gfx/video output maybe is (I haven't
>>> chosen my final gfx/video setup, but am currently using a cheap TNT2 
>>> gfx card).
>>>
>>> I heard that Promise is giving 'lack-lustre' Linux support, so I'm 
>>> totally open to not using Promise cards. I also heard
>>> that cards which do h/w RAID will give less load on the PCI bus.
>>>
>>> How should I do this? What h/w?
>>>
>>> Max.
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>>
>> _______________________________________________
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> 
>