Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Mark, Your supermicro controllers are bog-stock LSI SAS controllers so, functionality will be derived from their driver tree. Supermicro's UIO cards are essentially inverted PCIe cards so, no FUNCTIONAL changes, just electrical. Cheers, Dave -- Dave Graham Senior Systems Engineer Cirtas Systems 75 E Santa Clara Street, Suite 950 San Jose, CA 95113 (978) 239-2489 Dave at cirtas.com Follow the latest at the Cirtas Blog <http://www.cirtas.com/blog>! <http://twitter.com/cirtas> <http://www.facebook.com/Cirtas> <http://www.linkedin.com/company/cirtas-systems-inc> <http://www.cirtas.com/rss.xml> On 1/13/11 3:07 PM, "Mark Morlino" <mrmorlino at alaska.edu> wrote: >On Mon, Jan 10, 2011 at 10:31 AM, Bart Coninckx ><bart.coninckx at telenet.be> wrote: >> On Monday 10 January 2011 19:40:17 J. Ryan Earl wrote: >>> On Sun, Jan 9, 2011 at 10:03 AM, Bart Coninckx >> <bart.coninckx at telenet.be>wrote: >>> > Hi all, >>> > >>> > am reading the Novell docs on DRBD and one of the ways they mention >>>to >>> > speed >>> > up DRBD is using external metadata. Possibly a hard question to >>>answer >>> > but could someone indicate by what degree this would enhance speed >>> > (provided using >>> > a sufficient fast disk for the metadata, like a SSD)? >>> > >>> > thx! >>> > >>> > Bart >>> >>> A RAID controller with a backed-write cache essentially nullifies >>> any advantage there. A RAID controller that can instantly return on >>> FUA-writes is what you want. >>> -JR >> >> Hi, >> >> so the essence of your answer is that this is not a matter of having >>metadata >> internal or external, but rather of having the right RAID controller? >> Do you have examples of these in the major brands (HP, Dell, ...) ? >> >> thx! >> >> >> >> B. >> _______________________________________________ >> drbd-user mailing list >> drbd-user at lists.linbit.com >> http://lists.linbit.com/mailman/listinfo/drbd-user >> > >I would be interested in this information too (in my case I'd be >interested in any supermicro controllers that meet this requirement). >If I understand correctly, an FUA-write is a write-through request. >Doesn't that mean that the controller should not return until >everything has been physically written to the disk? It seems to me >that in order to return instantly on an FUA-write, the controller >would have to ignore the FUA request and return once the data has been >written to the cache. I don't see how it can both force physical disk >access and return instantly. Perhaps I'm missing something, it >certainly wouldn't be the first time. > >-Mark >_______________________________________________ >drbd-user mailing list >drbd-user at lists.linbit.com >http://lists.linbit.com/mailman/listinfo/drbd-user