Hy, Rich Puhek schrieb: > > Thedore Knab wrote: > > <SNIP>
> I'm not sure that there's significantly less work for RAID 0 than RAID > 5. RAID 1 will definately have less reads on any particular drive than > the other two (approzimately 50% will go to one disk, 50% to the other), > but will have greater writes (100% of writes will affect both disks on > RAID 1, it's possible some writes will not affect every disk on RAID 5, > I think). > As far as I know every drive will have to write some data. An example for RAID 5: 5 HDDs (everyony 30 GB) you will have a "resulting" disk with 120 GB of usable data ((5-1) * 30) 30 GB of Data for Parity-Checking will be divided on every HDD. (There is no complete Parity-Disk in RAID 5 - that's the difference to RAID 4 which *is* using a special Parity-Disk) If you write data, this data is divided on all hard-drives. It is more secure than RAID 0 and less secure than RAID 1. > Since you're looking at IMAP mail files, the data is probably > critical... too critical to trust in a single drive failure. You're > probably most concerned with read performance (since users will notice > lag in reading email... deleting messages can plod away just fine, > writing to the mail files is done by the MDA). Take a look at how much > space you need, or are likely to need in the future. If you need a lot > of space I'd go with RAID 5. If you want to really push the read > performance, buy another drive and go RAID 1. > > I'd stay away from RAID 0 unless it's fairly non-critical data, and if > you really need the throughput. An example I can think of would be > something like a web cache. > Yeah, but if you need high-speed you could use RAID 0+1.. (First mirror your drives, than sripe them. This is a bit more secure :-) ) > > --Rich > > _________________________________________________________ > > Rich Puhek > ETN Systems Inc. > _________________________________________________________ > regards Sebastian Nerz PS I hope the follwing links are okay: http://whatis.techtarget.com/definition/0,289893,sid9_gci214332,00.html http://www.win2000mag.com/Articles/Index.cfm?ArticleID=218 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]