On Tue, Feb 6, 2018 at 11:19 AM, Richard W.M. Jones <[email protected]> wrote: > On Tue, Feb 06, 2018 at 11:11:37AM +0100, Luca 'remix_tj' Lorenzetto wrote: >> Il 6 feb 2018 10:52 AM, "Yaniv Kaul" <[email protected]> ha scritto: >> >> >> I assume its network interfaces are also a bottleneck as well. Certainly if >> they are 1g. >> Y. >> >> >> That's not the case, vcenter uses 10g and also all the involved hosts. >> >> We first supposed the culprit was network, but investigations has cleared >> its position. Network usage is under 40% with 4 ongoing migrations. > > The problem is two-fold and is common to all vCenter transformations: > > (1) A single https connection is used and each block of data that is > requested is processed serially. > > (2) vCenter has to forward each request to the ESXi hypervisor. > > (1) + (2) => most time is spent waiting on the lengthy round trips for > each requested block of data. > > This is why overlapping multiple parallel conversions works and > (although each conversion is just as slow) improves throughput, > because you're filling in the long idle gaps by serving other > conversions. > [cut]
FYI it was a cpu utilization issue. Now that vcenter has a lower average cpu usage, migration times halved and returned back to the original estimations. Thank Richard for the infos about virt-v2v, we improved our knowledge on this tool :-) Luca -- "E' assurdo impiegare gli uomini di intelligenza eccellente per fare calcoli che potrebbero essere affidati a chiunque se si usassero delle macchine" Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716) "Internet è la più grande biblioteca del mondo. Ma il problema è che i libri sono tutti sparsi sul pavimento" John Allen Paulos, Matematico (1945-vivente) Luca 'remix_tj' Lorenzetto, http://www.remixtj.net , <[email protected]> _______________________________________________ Libguestfs mailing list [email protected] https://www.redhat.com/mailman/listinfo/libguestfs
