teach me about RAID 0
Ive tried looking for info on RAID level 0, but all I could find was big companies selling huge RAID systems for gigantic networks. Ive heard/read that RAID 0 can get performance in between EIDE and SCSI at an in-between price, but can anybody tell me something more specific than that? Maybe point me to a good URL or something?
RAID 0 basically means that you have two or more drives "striped" and acting like a single large drive. When you write a file to disk, it's broken up into small chunks and bits are stored on each drive. If you have two drives under RAID 0, half of the file will be on one drive and half will be on the other. When you need to read the file, both hard drives seek to the relevant place and return their half of the file. Since each drive is doing half of the work, it takes half the time to complete and thus the speed is twice as fast as a single drive. Because of this, a RAID 0 system will be faster than IDE and SCSI using drives of the same type.
Generally, SCSI RAID is only used in the situation you describe, as a major fileserver. In this situation a different type of RAID is often used to ensure redundancy as well as speed. SCSI RAID is also usually phenomenally expensive.
Promise has brought out the "FastTrack", which is a RAID controller that works with IDE drives. Go for a surf at http://www.promise.com/ and have a look. The FastTrack uses IDE drives and has many SCSI-like features. If you're interested, it will give you much better performance than a SCSI setup at a significantly lower price.
Before everybody starts flaming be that SCSI is better than IDE, I fully realise your opinion. SCSI is the superior solution in terms of scalability and reliability, but it carries a hefty price tag. For the general user, a single drive Ultra ATA setup will be great. The average user spends most of their time typing words into a word processor, discussion forum, IRC, ICQ whatever. The average gamer spends most of their time running around a level trying to frag as many people as possible. An expensive SCSI system won't give either type of person much of a performance gain.
IDE RAID 0 will give you great performance if you deal with large files often, and the price is quite cheap.
However if you're running a very disk-intensive setup like a proxy server, get SCSI by all means. SCSI drives are built to work hard, and they can literally grind all day long without overheating http://www.hardwarecentral.com/discussion/wink.gif
I've got a Medea VideoRAID 20Gb video drive, for video editing. It's four 5Gb seagate quantum drives, striped to operate as one drive through a supplied SCSI controller card (pci). It has a data throughput speed of 27 Mb/sec, and was several hundred dollars cheaper than an 18Gb Seagate Barracuda (and then you'd still ned to buy a SCSI controller card)
www.medeacorp.com has some expanation of RAID 0 (does the zero mean that the array has no redundancy?).
Go to this link for a simple explanation of the RAID levels:
Thanks for your help. Especially Geoff. The site you pointed to had detailed, simple info. Exactly what I was looking for. I now have a basic working knowledge of striping, mirroring and redundancy. And considering the size of my wallet (and the size of my needs), the only thing thats seriously in my grasp/desire is an IDE-based RAID 0 setup.
Probably 1 IDE RAID controller card with 2 HDs (probably about 4-6 GBs each). RAID 0 support only. Read that as striping, no redundancy (no data protection). Check out the site Geoff listed and you should get a decent working knowledge of RAID.
catch ya later,
I have recently bought a new system and in the process was involved w/one bidder who wanted to include a SCSI RAID disk subsystem. My enduring thought during talks was that if you use this method youneed to be the Felix Unger of backups, because if one disk goes, it all goes.