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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:blue'>Thanks (and sorry, just keep referring to Tim’s last email
which has the history in it – thanks everyone!). RAID1 with LVM it is…<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";
color:blue'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> mythtvnz-bounces@lists.linuxnut.co.nz
[mailto:mythtvnz-bounces@lists.linuxnut.co.nz] <b>On Behalf Of </b>Steve Hodge<br>
<b>Sent:</b> Thursday, 18 June 2009 1:31 p.m.<br>
<b>To:</b> MythTV in NZ<br>
<b>Subject:</b> Re: [mythtvnz] File System for RAID-5<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>On Thu, Jun 18, 2009 at 12:57 PM, James Booth <<a
href="mailto:james@booths.net.nz">james@booths.net.nz</a>> wrote:<o:p></o:p></p>
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<p><span style='font-size:10.0pt;color:blue'>Thanks Steve. RAID1 with LVM will
give me what I need, I was just hoping for RAID 1+0 so I could also get the
performance gain, which may be handy if I end up with three frontends all
watching and recording HD at the same time. If I had three RAID1 arrays as per
Tim’s email, and then put RAID0 over the top, could I subsequently add in
another RAID1 pair as per Tim’s directions, and then grow the RAID0
across the extra RAID1 pair without having to backup? I guess in short
I’m asking can you currently add disks/partitions to a RAID0
automatically without loss of data? I find many conflicting answers on the net.</span><o:p></o:p></p>
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<p class=MsoNormal>I wouldn't worry too much about the performance - hard
drives are at least an order of magnitude faster than HD streams. I believe TV3
runs around 11Mbps, a modern drive will easily handle in excess of 400Mbps. A
two disk RAID1 should be capable of nearly twice the single disk read speed -
when you've got multiple reads going (as its the case with streaming three
files to different frontends) RAID1 should be approximately the same speed as
RAID0 for the same number of drives.<br>
<br>
As far as I know you can't extend RAID0 arrays with mdadm either (at least the
man page says 1/4/5/6 only). My advice is that if you're really expecting to
extend the array any time soon just buy the drive now.<br>
<br>
By the way, that stuff you keep referring to from Tim's email was also written
by me :-)<br>
<br>
Cheers,<br>
Steve<o:p></o:p></p>
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