At a meeting with Intel folks a while back, they discussed the idea that future large devices — which we’re starting to now see — would achieve greater *effective* durability via a lower cost/GB that encourages the use of larger than needed devices. Which is a sort of overprovisioning, just more visible to the end user than conventional behind-the-scenes overprovisioning.
With very dense OSD servers, larger but faster devices have a certain appeal for greater ratios, especially if PCI slots are limited. The failure domain of course is still a consideration. > How did you settle on the P3608 vs say the P3600 or P3700 for journals? And > also the 1.6T size? Seems overkill, unless its pulling double duty beyond OSD > journals. > > Only improvement over the P3x00 is the move from x4 lanes to x8 lanes on the > PCIe bus, but the P3600/P3700 offer much more in terms of endurance, and at > lower prices compared to the P3608. > How big are your journal sizes, or are you over provisioning to increase > endurance on the card? > > It would seem the new P4800X will be a perfect journaling device with > >30DWPD, and even lower latency, even though it is ?low? storage size, 375GB > would still hold 15 25GB journals, which seems excessively large. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
