On 9/20/07, admin at lctn.org <admin at lctn.org> wrote: > I have a box with a single drive running Linux apps. Is there a way to > mirror the drive now, or can that only be done during the install process? It sounds like you're referring to a software RAID 1. This is possible and isn't really very difficult. If you have two disks, A and B, where A is the existing disk with data on it, then you would setup drive B as a RAID 1 device with its mirror drive as missing. Once the array was configured and running in a degraded mode, you would then copy the existing data from drive A to the new array on B. After all data was copied and verified you would setup drive A to be a RAID device and then add it to the degraded array with drive B. The array would then rebuild on A and you will be successfully migrated from a single disk to a RAID 1 setup. If you'll be booting off the RAID array there will be some additional configuration to get that working, but there are plenty of examples on the web to perform this process. I searched google using this search string and found a bunch of links: migrate single disk software raid1 linux Eric