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Discussion Starter · #1 ·
I have done a little research on this, but I thought I would ask the experts who visit this forum.


I have decided to take the plunge and rip my DVD's to hard drive. My plan is to set up a Raid 5 array with 4 300gig hard drives.


I am buying a new PC and plan on moving things around in my media network, swapping out an older PC, etc. My thought was to first use the new PC to rip the DVD's to hard drive prior to moving the PC's around and connecting the new one to the network. Ultimately, I want the Raid 5 disks connected to a different PC, not the new one. So here are my questions:


1. Is it possible to setup a Raid 5 array with hard disks that already have data on them? In otherwords, I would first rip the DVD's to hard drive, then assemble the hard drives in the Raid 5 array.


2. If I can not use existing hard drives (saving the data), is it possible to transfer a Raid 5 array to a different PC? I would hook up the hard drives and raid controllor in the new PC, rip the DVD's then move hard drivers and controllor to my media server PC.


Hope I stated my questions clearly. Thanks for the help!
 

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I dont consider myself an expert but here's my opinion if your interested.


1) No, i dont believe that you can take a few drives with data and create a RAID5 and retain the data.


2) yes, it sounds like it should work ok as long as you keep the drives in the original order / connections but i would test it first. rip a couple DVDs and try the move.


mike
 

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Discussion Starter · #3 ·
Quote:
Originally Posted by mcfreiz
I dont consider myself an expert but here's my opinion if your interested.


1) No, i dont believe that you can take a few drives with data and create a RAID5 and retain the data.


2) yes, it sounds like it should work ok as long as you keep the drives in the original order / connections but i would test it first. rip a couple DVDs and try the move.


mike
Thanks Mike.


From what I have read, I think you are right on both scores. But I could hope for an easier migration :rolleyes: .
 

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1) Is no for sure. Though in some instances you can add drive to a RAID 5 so you can start with a smaller number of drives and expand the RAID later. I did that. I built a RAID array with three drives and I had a 4th matching drive with my data. I built the array with 3 drives, copied the data from the one drive, and then added it to the array.


2) Are you doing Raid5 in hardware (setup through card or motherboard) or software (with the OS)? Hardware with a card is easy to move, just move card and drives and reconnect drives to the same place on the card). If you have the same or similiar motherboard in two computers you might be able to move the raid as well. If it in software, i.e., setup in OS I don't think you can move the RAID arrary and retain it. Also there is a lot of overhead associated with RAID 5 and writes to the hard disk. If you are using hardware, make sure it is doing these calculations for you. If you are using hardware that off loads it to the CPU or you are using the OS (software RAID) make sure you have a pretty decent CPU.
 

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Discussion Starter · #5 ·
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Originally Posted by secstate
1) Is no for sure. Though in some instances you can add drive to a RAID 5 so you can start with a smaller number of drives and expand the RAID later. I did that. I built a RAID array with three drives and I had a 4th matching drive with my data. I built the array with 3 drives, copied the data from the one drive, and then added it to the array.


2) Are you doing Raid5 in hardware (setup through card or motherboard) or software (with the OS)? Hardware with a card is easy to move, just move card and drives and reconnect drives to the same place on the card). If you have the same or similiar motherboard in two computers you might be able to move the raid as well. If it in software, i.e., setup in OS I don't think you can move the RAID arrary and retain it. Also there is a lot of overhead associated with RAID 5 and writes to the hard disk. If you are using hardware, make sure it is doing these calculations for you. If you are using hardware that off loads it to the CPU or you are using the OS (software RAID) make sure you have a pretty decent CPU.
Thanks Secstate. I am using a RAID controller card. I guess that would qualify as the "hardware" option you refer to? My plan is to move controller card and drives from one PC to the other. If I understand you correctly, that should work.

Thanks!

Ralph
 

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1 no

2 yes
 

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I was just browsing the forums and seen this so I had to register and ask you why you are using raid 5? You know it is slower than using say raid 1 which is just a mirror of the other hard drive. Why do you need a raid what are you trying to accomplish? And if you are moving the hard drives to another computer it will work but if the O/S is located on that raid you might have problems. I have done this many times and sometimes it works and other times it creates a lot of problems.
 

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The reason to use RAID 5 is not performance but space. RAID5 gives you the capacity of n-1 of the drives. So if you are using RAID5 and you have 4 drives in the array you have the capacity of 3. If you were using RAID 1 which gives you n/2 capacity you would only have the capacity of 2 drives. You are right that RAID5 takes a pretty big write performance hit but reads are generally pretty comperable to RAID 1. I use it in a server where reads are much more improtant than writes (it serves up media).
 

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Quote:
Originally Posted by ralphjb
Thanks Secstate. I am using a RAID controller card. I guess that would qualify as the "hardware" option you refer to? My plan is to move controller card and drives from one PC to the other. If I understand you correctly, that should work.

Thanks!

Ralph
Yes that should work fine.
 

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Ahh yes I wasnt using my head that makes perfect sense. I forget sometimes I can use my computer for other things besides gaming so I usually use raid 0 or 0+1 but 5 is perfect for this application.
 

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If you are just dumping DVDs that you own, then go with RAID 0. It will result in the best read and write performance. If you loose a disk, you can redo the array and redump the DVDs.
 

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What RAID 5 Card are you using? Most "RAID" cards on the market today only support RAID 0 or 1. The RAID 5 cards cost a lot more money. That's not to say it can't be done.


I have a Promise RAID 5 card in my server and it works great. The thing you have to keep in mind when buying RAID cards is you get what you pay for. My Promise only has a RAID 5 Write speed of about 40MB per second, about as fast as a single hard drive.


On the other hand, I just built a server for a small company using a 3Ware card, $$$$. After benchmarking it with the same tools I get about 80-90MB per second write speed. More then twice as fast with the same HDD's.


So again you get what you pay for. So what are you paying for?


links:
http://www.newegg.com/Product/Produc...82E16816102036 --> Promise Card $186

http://www.newegg.com/Product/Produc...82E16816116026 --> 3Ware Card $486
 

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"just dumping DVDs"


I don't know about you, but I don't enjoy all the time it takes to rip dozens of DVDs. Doubling the chance of array failure with Raid0 makes absolutely no sense for this application as ANY modern drive has plenty of speed for this application.
 

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Quote:
Originally Posted by Black Magic
If you are just dumping DVDs that you own, then go with RAID 0. It will result in the best read and write performance. If you loose a disk, you can redo the array and redump the DVDs.
Actually if you are that worried about performance...go with RAID 50 :) and get the best of both worlds.


Honestly though, you aren't going to get any better "performance" if it's a media server. As stated before, read speeds in a RAID 5 setup are plenty fast enough.
 

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Quote:
Originally Posted by usurpers26
Actually if you are that worried about performance...go with RAID 50 :) and get the best of both worlds.


Honestly though, you aren't going to get any better "performance" if it's a media server. As stated before, read speeds in a RAID 5 setup are plenty fast enough.
I think you mean RAID 10. With 50 you still have to calculate the parity and that's what slows things down so much,uses the most processing power, with the write on RAID5.
 

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Quote:
Originally Posted by Doc Holiday
I think you mean RAID 10. With 50 you still have to calculate the parity and that's what slows things down so much,uses the most processing power, with the write on RAID5.
No, I meant 50. I know 10 has faster writes...but you also need more HDD to maintain the same array size. "Performance" was a little tounge in cheek, seeing as how a regualr old raid 5 is plenty fast enough for a file server.
 

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I saw one time here some external stand alone sata 4 drive boxes for around $119 but cant find the thread again does any one have that link still.
 

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I have done raid 5 and had an issue when expanding the array with another drive. Long story short it took me a long time to recover the data (1.5 tb... not as long as re-ripping all the DVDs though)...


I have since gone with the simple mess of 7 250gb drives. I do not have redundancy, but if a drive goes I only have to rerip 50 movies or so instead of a few hundred.


I also can move my drives any where and in any order I want to any PC in the future.


IMHO - HTPCs and file servers do not need the redundancy, simplicity wins for me. Though I am sure many people have had no problems with their RAID 5 setups and probably have saved them time and headache. I am just one that ran into some bad luck.


In a nutshell... with RAID5 if everything goes well (even losing a disk) their great, if something goes wrong its a huge mess.
 

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Yup, if my RAID5 blows up one more time, I am going to just a bunch of separate disks too, darnit!!

Do yourself and get a UPS before you put the RAID5 into service. I speak from experience!!

I have a lower end hardware Promise SX6000, probably have better luck with fault tolerance with the $600 ones, if you can afford them.
 
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