Is the installer for mdk 8.2 going to make it easier to set up a software RAID under Linux? The main thing that steered me away from pure Linux software RAID after I got past all of the other snags was that I realized maintaining a bootable software RAID would be too much of a pain in the long run for me. The reason for this is that at the time that I decided to go with a 3ware controller I had to go through a long and complicated process to install Mandrake on my system. Doing it once isn't so bad, but when you guys release a new version of your OS I like to "upgrade" to it and going through the process of "upgrading" on a bootable software RAID just takes too long. (Now if I just had time to hack and try to optimize the 3ware drivers. :-))
civileme wrote: > > Not supported unless you are an expert... > > These RAID controllers are like unto WinModems--really software does the job, > which is not a bad thing because it does increase performance, but the > drivers just aren't there for linux. > > Here is an article I wrote for a LUG about the devices. > > OK if you want a hardware IDE RAID, there is one, and it is OS transparent. > > http://www.arcoide.com/productspages/products.html > > There is nothing else that is a pure hardware IDE RAID. > > Now we have controllers from CMD, Promise, Highpoint, and at least one other > plus 3ware. The 3ware controller, while it existed, had GPL drivers. Those > are all to some extent Software RAID. Here's how tey do it: > > Assume this line is your disk space: > > M----------------------------- > > where M is te master boot record. > After the controller does its thing, > > MR--------------------------R > > where the R are date and timestamp info. Also your drive has been destroked > in the BIOS to protect those areas. There is also a little info there to > toggle which lie the controller will tell the system about wat is real and > what is not. > > The result is that you have precisely one RAID extent, because of this > design. The R at the front of the disk is useless because LILO stomps all > over it, but the one at the other end is the one used (originally, only the > beginning was used so very early controllers are rotally incompatible with > linux and in fact their RAIDs are destroyed by an attempted install.) > > OK let's look at the software RAIDs > > "Hardware " Cards Linux Software RAID > > Extents 1 >16 > RAID Types 0, 1 0+1 0,1,4,5 > Identical drives Yes Irrelevant > Volume mgr No Volumes can be pieces of > up to 16 drives > Setup at install No, requires kernel mods Yes > Cost $30-100 extra Your time > > Journaling filesystems will work with both. > > If you really want to use the RAID controller in RAID mode, even after all of > this, there is some _experimental_ software to do so here: > > http://people.redhat.com/arjanv/pdcraid/ > > Of course, this is not for the faint of heart. The one advantage of having > this software probably is with Promise FastTrak controllers which do not > fully work as IDE controllers in linux. The most useful feature is > compatibility with Windows RAID for file exchange on a stand-alone dual-boot > system. (A small network has better alternatives). > > RAID0 does perform better for two drives as far as access time goes. It > performs even better if the drives are on different IDE channels, which is > achievable with linux Software RAID, but not with the controllers I have > tested. > > Finally, all of the IDE-RAID controllers are closed-source at this time. > They may all admit that linux software RAID is better in implementation than > theirs, but they are sorely afraid of giving their competitiors advantage in > the Windows market. > > WinRAIDs, anyone? > > Civileme > > ------------------------------------------------------------------------ > Want to buy your Pack or Services from MandrakeSoft? > Go to http://www.mandrakestore.com
Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
