<br><br><div class="gmail_quote">On Wed, Sep 21, 2011 at 2:09 PM, linux guy <span dir="ltr"><<a href="mailto:linuxguy123@gmail.com">linuxguy123@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<br><br><div class="gmail_quote"><div>Its very interesting that you bring this up. <br><br>Doesn't the ProRaid enclosure handle the RAID aspect entirely in hardware ? I understand that it will run from USB3.0 or SINGLE CHANNEL eSATA and thus I assume the drive(s) in it look like one big storage volume, when in fact they are a RAIDed storage device. That was one of the appeals of it to me.<br>
<br>Some of the other 4 bay RAID enclosures require either 4 SATA connections or a multiple channel SATA card/cable. The ProRAID doesn't.<br><br></div></div></blockquote><div><br>It looks like it does the RAID bit in hardware for this device. It's probably slow, given the price point. The other downside is that should something happen to the ProRaid, and you can't get another one for whatever reason, your data is likely not accessible at a price you would want to pay. <br>
<br> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="gmail_quote"><div>This is the MB I was intent on using.<br><br><a href="http://usa.asus.com/Motherboards/Intel_Socket_1155/P8H67M_PROCSM/" target="_blank">http://usa.asus.com/Motherboards/Intel_Socket_1155/P8H67M_PROCSM/</a><br>
<br>It has <br><br><span><b>Intel® H67(B3) Express Chipset</b> <br>
2 xSATA 6.0 Gb/s ports (gray)<br>
4 xSATA 3.0 Gb/s ports (blue) <br>
Intel Rapid Storage Technology Support RAID 0,1,5,10 <br><br>The RAID options are set in BIOS.<br><br>That would be a totally hardware based RAID, right ?<br></span></div></div></blockquote><div><br><br>Motherboard BIOS RAID is a "fakeRAID" in nearly every case. There are probably a few really high end server boards that come with a real RAID chip, but most figure their target market won't use it anyway and just leave them lots of slots to put a RAID card in. The so called "fakeRAID" setups have the same issue that the ProRaid/Drobo/etc. all have, if you don't get exactly the right hardware, and in many cases, firmware revision, your data can't be read back. Sort of defeats the purpose of RAID, no? <br>
<br> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="gmail_quote"><div class="im"><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204, 204, 204);padding-left:1ex">
RAID5 has a lot of deficiencies with respect to writing data,<br>
and it's not worth the efficiency benefits until you have a lot more<br>
than four drives, at which point you would be better with RAID6, or<br>
something else that allows more than a single drive failure.<br><div></div></blockquote></div><div><br>I'm not sure what to say. I haven't had a HD fail in the last 10 years. I'm not sure why I would need a RAID setup that would tolerate multiple drive failures.<br>
<br>What would the multiple drive failure tolerant RAID be ? RAID 1 ?<br></div></div></blockquote><div><br><br>As the other post mentioned, RAID6 = 2 drives may fail without any data loss. Multipule mirrors with a stripe over them AKA RAID10, might give you the same type of setup, with somewhat different failure modes. <br>
<br>IMO, unless you have enterprise $, or just want to have an extra RAID card/enclosure around that exactly matches what you are running, you should stick to software RAID. Linux md devices have proven quite reliable over the years. ZFS is another option. <br>
<br>Honestly, with Myth stuff, I wouldn't bother. Losing TV recordings is annoying, but not worth the trouble of an array. And you can get I/O bound very fast with recordings and playback in a myth system using RAID, particularly a small RAID5 like you are talking about. Performance of the array is about equal to a single drive, add in all the seeks you need to keep up with and your available I/O falls off fast. Using single drives in storage groups is a better solution, IMO. If you really must archive the TV shows, I would use 2+ drives for recordings in a Myth SG, then copy the recordings off to a large, slower, array later. <br>
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