Hi Eugene
I've followed up on my thought about using DTrace to try
and discover how the Solaris iScsi target is spending it's time.

I Googled and found these excellent articles:
http://blogs.sun.com/chrisg/entry/what_was_that_system_call
http://blogs.sun.com/ahl/entry/dtrace_for_linux
http://www.brendangregg.com/DTrace/prstatvstop.html

Reading Chris Gerhard's blog post makes me wonder if the
iscsitgtd "blocks for a long time waiting for an asynchronous event to occur."
on your snv_99 system.

And having read Brendan Gregg's page, the easiest way to get some
numbers seems to be to use his code called 'procsystime'.
Download it from here:
http://www.brendangregg.com/DTrace/procsystime

Ok, as a reference point, I ran procsystime while I copied the
file 'os200805.iso' (702,234kb) from a Windows box using
the Microsoft iscsi initiator to the OpenSolaris iscsi target.
So this should give a significant number of 'writes' to the target.
This is my home OpenSolaris box which is using 'BeleniX 0.7.1',
which is based on snv_93.

I've not got any more time tonight to think about what these figures mean,
but the results are shown below.
I ran it twice, just as a double check.
It took my (slow) system about 50 seconds to complete transferring the file.

Eugene, It would be interesting to see the equivalent results
from your server, and it would be good if it highlights a problem.
Best Regards
Nigel Smith

[EMAIL PROTECTED]:~# ./procsystime.d -a -n iscsitgtd
Hit Ctrl-C to stop sampling...
^C

Elapsed Times for processes iscsitgtd,

         SYSCALL          TIME (ns)
           pread             149720
           fcntl           35519712
           write          126424774
           yield          173121034
            kaio         4713542852
          pwrite        14434084623
         pollsys        22548334397
            recv        23333395481
        lwp_park       525433926625
          TOTAL:       590798499218

CPU Times for processes iscsitgtd,

         SYSCALL          TIME (ns)
           pread             126306
           fcntl           17647770
           yield           20008118
         pollsys           38305298
            kaio           76227575
           write          110422015
        lwp_park          550812201
            recv          826654447
          pwrite         1969525424
          TOTAL:         3609729154

Syscall Counts for processes iscsitgtd,

         SYSCALL              COUNT
           pread                 11
           yield               5805
           fcntl              10990
          pwrite              10990
         pollsys              11001
           write              11012
            kaio              21842
            recv              21991
        lwp_park             137067
          TOTAL:             230709

:---------------------------------------:

[EMAIL PROTECTED]:~# ./procsystime.d -a -n iscsitgtd
Hit Ctrl-C to stop sampling...
^C

Elapsed Times for processes iscsitgtd,

         SYSCALL          TIME (ns)
           fcntl           39902123
           yield          109715481
           write          138184743
          pwrite         1011558759
            kaio         1288324062
            recv        22194580158
         pollsys        33776145978
        lwp_park       635985043299
          TOTAL:       694543454603

CPU Times for processes iscsitgtd,

         SYSCALL          TIME (ns)
           fcntl           20261664
           yield           21415512
         pollsys           47292269
            kaio           89620164
           write          119919241
        lwp_park          622942322
            recv          841120557
          pwrite          954050549
          TOTAL:         2716622278

Syscall Counts for processes iscsitgtd,

         SYSCALL              COUNT
           yield               6184
           fcntl              10995
         pollsys              10995
          pwrite              10995
           write              10995
            kaio              21660
            recv              21990
        lwp_park             138108
          TOTAL:             231922
-- 
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