>I was told that if you lose one volume of a raid set you can replace >and the data will get rebuilt, but if you lose a second volume before >you get the first one rebuilt you will lose all the data -- irretrievably!
First I'll assume you are talking about software RAID and not hardware RAID. If you have a RAID5 array, that means that you are stripping data and a parity bit across multiple drives. If you lose one of those drives you can still retrieve all data from the remaining data and parity bits. If you lose a 2nd drive, then yes, you are lot of luck. But once you lose the first drive you are then alerted to replace that drive and all the data is rebuilt. You only exposure is to losing 2 drives at the same time. If you have RAID1 then you are mirroring your data to two drives. Each identical to the other, if one fails you use the other. You can then replace the drive and rebuild the mirror. Again, losing 2 drives and your hosed. If you have RAID0 array you are stripping your data across multiple drives, WITHOUT, a parity bit. No protection, you lose a drive you lose all your data. Now if you have a hardware RAID you can also have "hot spares", basically a spare drive just sitting and waiting to take over in the event of a failure. RAID5 & RAID1 are designed to PROTECT your data, it's not a bad thing. Mark D Pace Senior Systems Engineer Mainline Information Systems 1700 Summit Lake Drive Tallahassee, FL. 32317 [EMAIL PROTECTED] Office: 850.219.5184 Fax: 850.219.5050 http://www.mainline.com
