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Old 09-25-2012, 10:50 AM   #5
Brett Thomas
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Join Date: Apr 2009
Posts: 164
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Quote:
Originally Posted by lferrante View Post
Nice article. Two things I'd like to mention. One is that I hope you can add something about software RAIDs and their incorporations across different OSs and most impotantly what happens when the OS needs rebuilt, or the disks get transferred to another PC etc.

Second, I've been working with RAIDs in our office for years now on Dell PowerEdge machines and needed to benchmark a RAID50 vs a RAID10 and found that RAID10 is vastly superior except a hardly notable difference in CPU usage that could be completely unrelated. The short benchmark and details are posted here.

http://professorjunkdrawer.blogspot....benchmark.html
Welcome, lferrante! I'm glad you enjoyed the article.

I planned to follow up with the discussion on software RAID in my covering of building a simple MDADM RAID5 array...so stay tuned, and hopefully you will find what you're looking for there. I've found that on Linux, software is vastly superior (as mentioned in my article), as it does not require rebuilding at all between OS changes. Windows, I'll have to do some research - the addition of RAID 0/1 in Windows is a nice one but I've not tested re-installs of the OS. I would, however, assume that to be fairly transparent - the encoding is part of the volume header's "Superblock" and should be visible to any Windows version that supports RAID, with no rebuilding required.

As far as speed tests - thank you for the link! RAID10 should ALWAYS be faster than RAID5/6, as there is no need to calculate a parity block. However, its sub-optimal use of disk space and arguably lower fault tolerance vs RAID6 on any array larger than four disks makes it a difficult balance. I've found a well-tuned RAID5 can more than supply a small office or (far more demanding) home theater setup! In the end, the choice between solutions at that level comes down to application goals - a big portion of what will determine a good setup involves WHAT you're serving (file size wise) and to how many users.
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