My guess is that it is related to the window size. Try different window sizes and you will see different results.
Actually, didn't someone else bring this up a month or so ago with regards to windows file shares? -Mark C. On Thu, Mar 29, 2012 at 12:45 PM, Jeff Clement <j...@nddn.net> wrote: > I would have thought my netcat test would only be limited by the GigE card > and PCI-X bus (which should have enough bandwidth to saturate GigE). > > Using ncat, instead of ncat, I get 118 MB/s dumping from /dev/zero and 95 > MB/s from my array. I never would have guesses that nc had so much > overhead! > > Perhaps I was mistaken and I really don't have the problem I think I have > with network performance. It's Samba... > > 12:40:24-root@screamer:/mnt/tmp/ISOs $ dd > if=linuxmint-12-gnome-dvd-64bit.iso > bs=8k of=/dev/null > 130190+1 records in > 130190+1 records out > 1066518528 bytes (1.1 GB) copied, 29.3757 s, 36.3 MB/s > > Thanks for all the help. Now I have some direction as to what I need to be > looking at more. > > Jeff > > * Gustin Johnson <gus...@meganerd.ca> [2012-03-29 11:18:14 -0600]: > >> netcat (or ncat) would still be subjected to PCI/PCI-X bus limitations. >> >> So basically when troubleshooting I would change the cables, then the >> switch, then the NICs. The regular PCI bus tops out at a gigabit, so you >> should still be able to test with a standard PCI (though PCI-E would be >> better) NIC. Intels are pretty nice but pricey for PCI (~$50). I have >> used SMC2-1211TX which are cheap and pretty good Gig-E NICs. >> >> Install atop to help figure out why a CPU/core gets pinned. >> >> Use ncat (part of nmap) as it is a cleaner more modern implementation. I >> would build it from source. >> >> If you have the memory, try creating a RAM disk and put a real 1 or 2 GiB >> file in it. Use that to transfer as /dev/zero can give weird results >> sometimes and /dev/urandom puts load on the CPU and bus. >> >> Hth, >> >> On Thu, Mar 29, 2012 at 9:12 AM, Stolen <sto...@thecave.net> wrote: >> >>> Try using iperf to test *just* the network. >>> http://sourceforge.net/projects/iperf/?_test=b >>> >>> >>> On 12-03-29 08:50 AM, Jeff Clement wrote: >>> >>> I don't think that's the problem though. I can get > GigE read speeds >>> from my array. >>> >>> 08:46:27-root@goliath:/etc/service/dropbox-jsc $ hdparm -t >>> /dev/lvm-raid1/photos >>> >>> /dev/lvm-raid1/photos: >>> Timing buffered disk reads: 512 MB in 3.00 seconds = 170.49 MB/sec >>> >>> Write speeds are obviously slower but decent. >>> >>> 08:47:48-root@goliath:/mnt/photos $ dd if=/dev/zero of=test bs=8k >>> count=100000 >>> 100000+0 records in >>> 100000+0 records out >>> 819200000 bytes (819 MB) copied, 10.3039 s, 79.5 MB/s >>> >>> So I would expect that I should be able to saturate GigE on the reads and >>> do >>> ~80 MB/s on the writes. >>> However what I'm seeing whether I'm doing IO to disk or just piping from >>> /dev/zero to /dev/null is around 40MB/s. It looks like my bottleneck is >>> actually the network. The netcat test should eliminate disk IO and also >>> eliminate the PCI-X bus as the bottle neck. I think... >>> >>> Jeff >>> >>> * Andrew J. Kopciuch <akopci...@bddf.ca> <akopci...@bddf.ca> [2012-03-29 >>> >>> 08:18:14 -0600]: >>> >>> >>> Anyone have any ideas what I should be looking at in more detail. >>> >>> Thanks, >>> Jeff >>> >>> >>> >>> You are probably limited by the i/o speeds of the hard drives. Your LAN >>> can >>> sustain around 125MB/s, but your hard drives will not be able to read / >>> write >>> that fast, you will be bound to their maximums. >>> >>> HTH >>> >>> >>> Andy >>> >>> >>> >>> >>> _______________________________________________ >>> clug-talk mailing list >>> clug-talk@clug.ca >>> http://clug.ca/mailman/listinfo/clug-talk_clug.ca >>> Mailing List Guidelines (http://clug.ca/ml_guidelines.php) >>> **Please remove these lines when replying >>> >>> >>> >>> >>> _______________________________________________ >>> clug-talk mailing >>> listclug-talk@clug.cahttp://clug.ca/mailman/listinfo/clug-talk_clug.ca >>> >>> Mailing List Guidelines (http://clug.ca/ml_guidelines.php) >>> **Please remove these lines when replying >>> >>> >>> _______________________________________________ >>> clug-talk mailing list >>> clug-talk@clug.ca >>> http://clug.ca/mailman/listinfo/clug-talk_clug.ca >>> Mailing List Guidelines (http://clug.ca/ml_guidelines.php) >>> **Please remove these lines when replying >>> > >> _______________________________________________ >> clug-talk mailing list >> clug-talk@clug.ca >> http://clug.ca/mailman/listinfo/clug-talk_clug.ca >> Mailing List Guidelines (http://clug.ca/ml_guidelines.php) >> **Please remove these lines when replying > > > > _______________________________________________ > clug-talk mailing list > clug-talk@clug.ca > http://clug.ca/mailman/listinfo/clug-talk_clug.ca > Mailing List Guidelines (http://clug.ca/ml_guidelines.php) > **Please remove these lines when replying _______________________________________________ clug-talk mailing list clug-talk@clug.ca http://clug.ca/mailman/listinfo/clug-talk_clug.ca Mailing List Guidelines (http://clug.ca/ml_guidelines.php) **Please remove these lines when replying
