Guide To RAID Over the last few weeks RAID seems to be comming up over and over the boards so here's a quick rundown: The Basics: RAID = Redundant Array Of Inexpensive Disks So you need 2 or more disks to create a raid array. Ideally the disks must be identical, same size, manufacturer and model. RAID will work with drives of different manufacturers/models/sizes, but the lowest raid performace and size will only be as good as the poorest drive. The Types: SATA RAID is raid using the newer Serial ATA disks, this is common feature on newer motherboards IDE RAID is raid using older Parallel ATA disks (IDE), this is an option on some motherboards or by the use of a PCI raid card SCSI RAID (Unsuprisingly) RAID Using a SCSI controller and disks - Very fast, very reliable and very expensive. The Flavors of RAID: RAID 0 = Striping, 2 or more disks become 1, using a stripe, when data is written it is written accross both disks in a stripe, each disk gets half each, this leads to faster access times as the heads don't have to move as far. The Benifits = Faster Access Times The Problems = If you loose 1 disk you loose the data on both RAID 1 = Mirroring = 2 disks are used in a mirror. The data is written to both disks - they are complete copies of each other The Benifits = Redundancy - If you loose a disk, no problems, the other takes over and no data is lost The Problems = 2X160Gb drives in a mirror = 160Gb space, so can be expensive RAID 5 = Parity and data is striped accross 3 or more drives, you have the speed increase of RAID 0, but the due to the parity bits the array can loose a drive without data loss. The Benifits = Good perfomance, and good redundancy The Problems = Cost - 3+ identical drives and a mid to high end RAID controller are required RAID 4 = Similar to RAID 5, but slower as a drive is used as a dedicated parity drive, which adds a bottleneck RAID 3 = Same as RAID 4, but with a different stripe size JBOD = This is an option on many RAID controllers, it stands for Just A Bunch Of Disks and is a way of having a bunch of different sized disks show up as 1 drive. No performance increase or redundancy is provided. I wouldn't say this is really a RAID array as such There You Go! Hope someone finds this usefull!
thank you that helps but can I use SCSI drive with an nforce 4 sli motherboard and how do you raid two drives
Ok, Part 2...... Actually creating an array is different for each card/board Normally (after plugging the disks in) you will see the raid controller initialize (Promise/Adaptec/etc) and search for the disks, then you have the option of entering the raid options menu, CRTL+A on adaptec cards. From there there should be a menu with options to choose the drives to use, choose the type of RAID to use (RAID 0 or 1 will be the only options on most on-board RAID controllers - RAID 5 etc are normally only found on more expensive add-in cards), create, and initalise the array. For those planning on creating an array which will be booted from, be sure to check the boot BIOS is enabled on the controller, and that it is a selected boot option in the motherboard's BIOS. If you are planning on installing an operating system make sure you press F6 when prompted and have the RAID controller's driver diskette handy otherwise the drives will not be seen by the install process.
You would need a SCSI raid card and 2 indentical scsi disks. I doubt your board has on-board SCSI RAID, very few boards do, the few that do are high-end server boards
I'm not sure why people even want raid? http://www.intel.com/design/servers/boards/se7520bd2/ is an example of one. But there is really no need for on the desktop.
My OS install still not recognizing my RAID config... and I put the diskette in... it's just not detecting it... it keep asking me for more stuff.... I have the ABIT KN8 SLI board...
Yea i had the same problem as errorrr, when windows was installing and it asks if u want to setup a raid i pushed the key then it says insert disk and it just doesnt read it. I set the raid up before hand by following the steps located in the DFI Lanparty SLI-DR manual and still nothing. I will be reinstalling windows again soon so ill try again.
I thought RAID stood for Redundant Array of Independant Disks. I myself have a 1.6TB RAID 5 with 4 disks. I think it can be explained more easily that in this case, one disk is used as an image for others while the rest split up data. When one disk goes down, the parity can restore the rest of the information on the working disks and keep the system up until you can get a replacement...of which the array will rebuild itself to original settings. In my case, all the disks act as a parity, so that even if "the image" disk goes down, another will take it's spot. Of course you lose capacity. And if it has more information than the image can take, the image acts as a regular splitting disk. Hope that helps
RAID Editions erm anyone got any experience/opinions on whether WD (for example) 'raid edition' drives are better to use than ordinaries? They seem to have 8MB caches instead of 16 would this make a difference in this kind of purpose? thanks
What's the optimal block size for desktop use? I have 4 raptors in a raid0 config but it benches no faster than when I had 2 of them in a raid0. I left the block size at 64k, I was wondering if it'll go faster if I reduce it to 4k