Vasu Dev wrote: > On Mon, 2009-10-19 at 11:32 -0700, Joe Eykholt wrote: >> The FC-LS spec. says ELS timeouts should be 2 x R_A_TOV. >> The FC-GS spec. says CT timeouts should be 3 x R_A_TOV. >> >> We've been using E_D_TOV for both of those. >> >> Change for all ELS and CT requests except FLOGI, which we >> leave at 2 seconds (using E_D_TOV). One could argue that >> R_A_TOV is locally determined until after FLOGI succeeds. >> >> This does change FLOGI for vports which becomes FDISC. >> This does not change the REC/SRR timeout which is 2 seconds. > > The FCP sec 11 suggests REC timeout at least >= E_D_TOV + 1 seconds and > default E_D_TOV as 2s, that means it should be least 3 second.
A round trip time with 1 second to spare. Pretty tight if E_D_TOV is accurate. > The FCP > standard requires minimum value for REC_TOV and as far as I can tell > there is no restriction on larger REC_TOV value, that means we could > choose higher values True - but I look at FC-LS as giving the recommendation for any ELS. > also and I think we should since FCoE is mostly > used with 4G FC target ports and currently we allow upto 1024 commands > with each cmd could be up to 512KB and I've seen some config having low > IO throughout. So may be it should 20-30 seconds to avoid pre-mature REC > attempts. Agreed - to be safe, moving to the 2*R_A_TOV FC-LS recommendation seems a safe approach. -- james > > I heard some HBA uses ULP_TOV (FC_SCSI_TM_TOV etc in libfc) as much as > 60HZ, so perhaps that also need to be increased to avoid thrash due to > too early timeout and retry attempts. > > What do you think ? > > Vasu > > > _______________________________________________ > devel mailing list > [email protected] > http://www.open-fcoe.org/mailman/listinfo/devel > _______________________________________________ devel mailing list [email protected] http://www.open-fcoe.org/mailman/listinfo/devel
