On 2017-07-18 10:34 AM, Lentes, Bernd wrote: > > > ----- On Jul 17, 2017, at 11:51 AM, Bernd Lentes > bernd.len...@helmholtz-muenchen.de wrote: > >> Hi, >> >> i established a two node cluster with two HP servers and SLES 11 SP4. I'd >> like >> to start now with a test period. Resources are virtual machines. The vm's >> reside on a FC SAN. The SAN has two power supplies, two storage controller, >> two >> network interfaces for configuration. Each storage controller has two FC >> connectors. On each server i have one FC controller with two connectors in a >> multipath configuration. Each connector from the SAN controller inside the >> server is connected to a different storage controller from the SAN. But >> isn't a >> SAN, despite all that redundancy, a SPOF ? >> I'm asking myself if a DRBD configuration wouldn't be more redundant and high >> available. There i have two completely independent instances of the vm. >> We have one web application with a databse which is really crucial for us. >> Downtime should be maximum one or two hours, if longer we run in trouble. >> Is DRBD in conjuction with a database (MySQL or Postgres) possible ? >> >> >> Bernd >> > > Is with DRBD and Virtual Machines live migration possible ? > > > Bernd
yes, but dual-primary is needed (this is how the Anvil! does live migration). With DRBD 9, you can set it up to momentarily do dual-primary to support live migration, though I have not used this myself yet. With dual-primary, you need to be sure a few things are in place (ie: proper fencing, but you need that anyway, a cluster resource manager, etc). -- Digimer Papers and Projects: https://alteeve.com/w/ "I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops." - Stephen Jay Gould _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
