Are you familiar with GlusterFs / Ceph ? Eero 19.11.2015 8.34 ip. "Lamar Owen" <lowen at pari.edu> kirjoitti: > On 11/18/2015 04:42 PM, John R Pierce wrote: > >> the /really/ hard one when rolling your own highly redundant systems with >> high data integrity needed for things like transactional database servers, >> is implementing redundant storage controllers with shared writeback >> cache... you pretty much have to get into EMC class hardware for this >> level of reliability with data integrity and performance. and thats >> /really/ expensive stuff. >> > Yes it is, because it really is that hard to do shared writeback cache. > EMC, Nimble, NetApp, and the like cost what they do because of those HA > features. EMC storage processors have specialized shared backplanes and > replicated write caches just in case an SP goes down while the data to be > written is in cache and has yet to be committed (so that the trespassing SP > can write the correct data to disk). They also have dedicated battery > backup units and the whole concept of the 'vault' drives to specifically > save the write cache in a powerfail emergency. > > But I would love to see something in the free software space that did that > kind of thing, with appropriate hardware. > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >