Originally posted by schnupie
... others mirror a drive by createting an exact copy of one drive on a second drive in realtime, so if one drive fails, the other one can kick in after just a little bit of downtime.
Sorry, but that's not true. With RAID 1 (mirroring) if one drive fails the system should take that drive offline, report an error, but will still keep on running.
Go take a look at this site: http://www.acnc.com/04_01_00.html it's a very good introductory site describing what all the different RAID levels are.
In most RAID 0 implementations I've seen/done, the 'whatever' is a value you select when you initialize the RAID set for the first time. It's called the 'chunksize' and determines how many bytes are written to one drive before moving onto the next. The optimum value for chunksize very much depends on what it's being used for: e.g. a filesystem, or a raw data partition (like Oracle). The size of the application/filesystem 'blocksize' being used (which can also be tuned to suit the type of data being processed) should determine the value of 'chunksize'.Originally posted by rharder
..'cause every other byte or bit or whatever is stored on the "other" hard drive!
Both . If the OS support software RAID natively, then you can use that (whatever its implementation happens to be) or you may be able to use/buy a layered product that implements it (and works on your OS). For software RAID you don't need any special hardware, though it often makes more sense to have a couple of controllers with RAID members spread across them so that you build protection from controller failure into your design and also get the benefit of increasing controller bandwith.Originally posted by PowerBookDude
Do you need a RAID controller for a RAID or can you do with out it?
That woul be Raid Level1.Originally posted by PowerBookDude
1. What RAID should I use? I will have two 80GB drives in a tower running Mac OS X Server. And I want the second drive to mirror the first
2. So it is better to have hardware RAID? Is there any RAID cards that work with Mac OS X Server? If so, could you tell me?Hardware Raids do not use the cpu(s) to perform their tasks. Therefor softwareraids were out of question for a long time. Situation has chanhed a bit due to the much increased processor-capabilities. Still on high-performance-servers under heavy load a hardwareraid ist the better choice.[/B]
A raid-controller for MacOSX? Difficult. I read somewhere, that Adaptec and Atto have released some drivers for MacOSX.