> Additionally when you mirror disks directly with drbd, your drbd-resources are fixed to the size of the disk-pairs. When you mirror lvm volumes, they can have the size they need to have to fulfill their > task. You can have drbd-resources of only some MB but also resources of the size of two or three of your disks toghether.
Thank you Arnold for your reply. I think you may have hit the impedance mismatch on the head! You are recommending putting DRBD on top of a large LVM volume. In fact, I was planning on putting LVM on top of a bunch of mirrored (DRBD) physical drives. When one puts DRBD on top of LVM one risks losing the entire logical volume if a single drive fails. In such a case, DRBD would have to re-sync the entire logical volume. By putting LVM on top of DRBD, DRBD would only have to re-sync the failed hard drive. That being said, I just discovered today that DRBD volumes are a relatively new feature. Prior to version 8.4 one would have to create a separate DRBD resource for every synchronized block device. Obviously, this would be really annoying and so using DRBD on top of LVM makes sense. However, I was planning on defining each physical hard drive as a DRBD volume within one resource then using LVM to stripe/aggregate them. So perhaps the reason I have found little on the subject is that most people have traditionally put DRBD on top of LVM instead of the other way around. Ted Young _______________________________________________ drbd-user mailing list [email protected] http://lists.linbit.com/mailman/listinfo/drbd-user
