Drew wrote: >> Wrong list - that's for the Linux MD RAID subsystem (mdadm, /dev/md* and >> friends). You're looking for ataraid-list: >> >> http://www.redhat.com/mailman/listinfo/ataraid-list >> >> Which is the place for discussion of dmraid development. > > Evening Byrn, > > I am aware that the dm-raid list was the best one if he had a dm-raid > specific question. However from what I read it sounded like he was > interested in knowing what the differences were between ata/dm-raid > and md (software) raid. Being a lurker on both lists I felt that the > folks over at md would be a better choice. He was asking where the RAID is done in dmraid. I think the response of the MD folks to that question based on past experience, would be either very general or something like: "Huh? Go ask the device-mapper guys" ;) If you're using dmraid to activate volumes on an ata RAID / fakeraid adapter then all the RAID work is being done in the kernel by device-mapper. When dmraid activates a volume, it reads the metadata from the disk that describes the array and translates that into a device-mapper table, usually using some combination of the linear, dm-raid1, and dm-raid45 targets. These are the kernel modules that implement the RAID algorithms (dm-raid1 uses the kernel thread kcopyd to do the actual work - you'll see this process consuming some resources on a system with a busy mirror). For more information on the targets and the tables that are used to configure them see Alasdairs talks on LVM/device-mapper here: http://people.redhat.com/agk/talks/ Regards, Bryn. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
