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

[Robin Hill]

On Thu Apr 07, 2011 at 09:39:53AM +0100, Simon Hobson wrote:

> Robin Hill wrote:
> 
> >If you're planning on that number of drives, I'd recommend RAID6 instead
> >of RAID5. RAID5 leaves you very vulnerable to getting a second drive
> >failure during a rebuild, losing the array altogether.
> 
> Indeed. But for Myth media storage, is it better to have single 
> drives and multiple storage directories ? If writing multiple streams 
> to a RAID array, then that involves all the drives and performance 
> isn't necessarily better than a single drive (all that seeking). I 
> believe Myth will try and spread recordings across multiple storage 
> directories - thus aiming to write a single stream on each drive.
> 
That depends on whether you're just looking for capacity, or whether you
want some form of redundancy. If you're willing to accept the loss of a
chunk of the data then multiple storage directories is certainly the way
to go - better performance with multiple streams, lower CPU usage, and
higher capacity.

If you want the redundancy though, I'd always use RAID6 rather than
RAID5 for more than 4-5 drives (especially if they're modern
large-capacity drives, which can take days to rebuild).

Cheers,
    Robin
-- 
     ___        
    ( ' }     |       Robin Hill        <myth at robinhill.me.uk>  |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
Url : http://www.mythtv.org/pipermail/mythtv-users/attachments/20110407/655bee50/attachment.bin