Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 2017-08-25 04:08 PM, Gionatan Danti wrote: > Il 25-08-2017 22:01 Digimer ha scritto: >> On 2017-08-25 03:37 PM, Gionatan Danti wrote: >> >> The overhead of clustered locking is likely such that your VM >> performance would not be good, I think. > > Mmm... I need to do some more testing with fio, it seems ;) > >> With raw clustered LVs backing the servers, you don't need cluster >> locking on a per-IO basis, only on LV create/change/delete. Because LVM >> is sitting on top of DRBD (in dual-primary), live-migration is no >> trouble at all and performance is good, too. > > True. > >> GFS2, being a cluster FS, will work fine if a node is lost, provided it >> is fenced succesfully. It's wouldn't be much of a cluster-FS >> otherwise. :) > > So no problem with quorum? A loss of a system in a two-node cluster > seems to wreack havok on other cluster filesystems (Gluster, for > example...) > > Thanks. Quorum is optional (an often misunderstood thing). https://www.alteeve.com/w/The_2-Node_Myth We've run without quorum for every system we've built over 5+ years, across dozens of sites and never once needed it. A proper fence setup, which is needed regardless, is fine. In our opinion, the complexity of a third quorum node is not justified for the limited benefit of quorum. Simplicity is simply too valuable in HA. -- 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