Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
> >So I played around with AOE, ISCSI, GNBD and such stuff but they > >are all not fast enough and not reliable enough for me. So my > >conclusion is, that ethernet-storage is not an option (except drbd > >which is fast and reliable). > > > Where were your bottleneck? Hmm, reading performance is the bottleneck. In general I think we can assume that on an average Server (in my setup) 90% of the i/o is reading and 10% is writing. Thats why I have chosen local disks (for reading), so i take away 90% of the network load. > >-Replicate each logical volume via drbd to one or 2 storage hosts > >so that we have a current-copy in case of a crash. > >-In case of a crash of a xen host I could copy the logical volumes > >(xen vms) from the storage host to another host with another cheap > >harddisk or just mount the drbd partition from the storage host > >and continue running the server. > > > > > This could fly, but I believe you will have to maintain the same info > twice, the LV and the drbd resource, twice the work. Yeah, but both, lvm and drbd are known to be performant and to "fly". > >Maybe I could even run the drbd in master-master mode and backup a > >snapshot of the drbd partition instead of the drbd partition. > > > > > That one is odd, I am not sure I understand. Can you clarify? This was an error from me, I thought I could only reliably backup a snapshot of the drbd-slave device if it is in master-mode, but that was nonsense, of course I can backup the snapshot of the drbd-slave device. The Backup of the snapshots e.g. to a local scsi-streamer on the storage-host should be much faster than backup each and every vm via network. It all should rock, I just read that I even can live-migrate my xen-domains from one server to the other with drbd 8.0.6.. I have just decided to even get rid of the drbd-storage server. Instead I will have 3 xen-dom0 Servers and each of them drbd- replicates their vms to another xen-server and so I should be able to migrate or boot a xen-vm on another server, regardless of which server just has a problem, should be raplaced and so on. Christoph -- Christoph Adomeit GATWORKS GmbH Reststrauch 191 41199 Moenchengladbach Sitz: Moenchengladbach Amtsgericht Moenchengladbach, HRB 6303 Geschaftsfuehrer: Christoph Adomeit, Hans Wilhelm Terstappen Christoph.Adomeit at gatworks.de Internetloesungen vom Feinsten Fon. +49 2166 9149-32 Fax. +49 2166 9149-10