Michel Posted March 5, 2003 Report Share Posted March 5, 2003 If read some about raids and i have the impression that you have to choose between speed and safer info-keeping, but isn't there a raid that combines two, beause... if you have a raid that duplicates info for safe info-keeping and you want to read some blocks, can't (say raid of 2 disks) disk 1 reads the first block, while disk2 reads the next???Now, you'll also have a speed-increase I believe...??? Is there such a raid??? Thanks. Quote Link to comment Share on other sites More sharing options...
mtweidmann Posted March 5, 2003 Report Share Posted March 5, 2003 Yes you can have both the extra speed AND data protection. I got this off Webopedia.com which should answer your question: There are number of different RAID levels. The three most common are 0, 3, and 5: # Level 0: Provides data striping (spreading out blocks of each file across multiple disks) but no redundancy. This improves performance but does not deliver fault tolerance. # Level 1: Provides disk mirroring. # Level 3: Same as Level 0, but also reserves one dedicated disk for error correction data. It provides good performance and some level of fault tolerance. # Level 5: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Remember the more you want it to do the more its going to cost. Quote Link to comment Share on other sites More sharing options...
ral Posted March 5, 2003 Report Share Posted March 5, 2003 I think your looking for RAID 5. You need to have three hard drives and a raid controller to so this. Each drive should preferably on spearate IDE cables. Data is written to all drives and both read from all drives. This also results in data protection. If one of your HD's should go down, plop in a new one and it will reconstruct the broken one from the data in the other two. RAID 5 does not mirror or duplicate your data but rather provides writes parity data to allow it to reconstruct a damaged gard drive. You will loose 33% of you total storage space though. If you have only two drives you may want to try RAID 1 instead. Each drive should preferably on separate IDE cables. Identical data is written on both drives drives and both read from all drives. This results in data protection. If one of your HD's should go down, plop in a new one and it will reconstruct the broken one. This results in faster read but slower writes. You can use a RAID 1 solution using either hardware or software. Hope this helps. Quote Link to comment Share on other sites More sharing options...
ral Posted March 5, 2003 Report Share Posted March 5, 2003 I forgot to mention with RAID 1 you loose 50% of your total drive space. With RAID 5 the loss is as follows: 3 drives = 33% 4 drives = 25% 5 drives = 20% Quote Link to comment Share on other sites More sharing options...
Guest nhaughton Posted June 24, 2003 Report Share Posted June 24, 2003 I forgot to mention with RAID 1 you loose 50% of your total drive space. .../quote] How does that occur? I can't find any mention of this in the various Raid howto's and documentation that I have seen, so I'm curiious. Quote Link to comment Share on other sites More sharing options...
Guest GhostDX Posted June 28, 2003 Report Share Posted June 28, 2003 This is one of my favorites topics, simply because I love what RAID offers and my company actually patented RAIDx2 (or RAID squared). Anyway, one that was not mentioned is RAID 0+1. Which takes 4 drives but gives you the benefits of both RAID 1 and 0 (as the name implies) For more info you can check out http://www.acnc.com. Then click on the tab RAID.edu. Great info on oh how RAID works as well advantages and disadvantages Quote Link to comment Share on other sites More sharing options...
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