Shachar f, on 11/25/2009 07:57 PM wrote: > I'm running open-iscsi with scst on Broadcom 10Gig network and facing > write latency issues. > When using netperf over an idle network the latency for a single block > round trip transfer is 30 usec and with open-iscsi it is 90-100 usec. > > I see that Nagle (TCP_NODELAY) is disabled when openning socket on the > initiator side and I'm not sure about the target side. > Vlad, Can you elaborate on this?
TCP_NODELAY is always enabled in iSCSI-SCST. You can at any time have latency statistics on the target side by enabling CONFIG_SCST_MEASURE_LATENCY (see README). Better also enable CONFIG_PREEMPT_NONE to not count CPU scheduler latency. > Are others in the mailing list aware to possible environment changes > that effext latency? > > more info - > I'm running this test with Centos5.3 machines with almost latest open-iscsi. > > Thanks, > Shachar -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-is...@googlegroups.com. To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/open-iscsi?hl=en.