Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi all, up to now to use LVM (thick) provisioning to provide virtual disks for VMs: RAID => LVM => LV => DRBD => KVM/QEMU (virtio). We would like to be able to take snapshots from our virtual disks in order to be able to use them as readonly source to consistent backups. Therefore we would need to introduce a LVM thin provisioning layer somewhere. A. TP below DRBD RAID => LVM => LVM-TP => LV => DRBD => KVM/QEMU (virtio) - simple setup - I suppose going back to an older snapshost would this break DRBD and require a complete resync/verify run B. TP on top of DRBD RAID => LVM => LV => DRBD => LVM => LVM-TP => LV => KVM/QEMU (virtio) - complex setup - more layers affect reliability and performance - snapshots are replicated and consistent - additional diskspace for snaphosts is limited by the DRBD volume size an connot be shared across volumes. I would like to discuss the pros and the cons of both approaches while considering internal vs. external metadata. Thanks in advance Michael