On Fri, 2007-10-19 at 16:30 +0200, BERTRAND Joël wrote: > Ming Zhang wrote: > > On Fri, 2007-10-19 at 09:48 +0200, BERTRAND Joël wrote: > >> Ross S. W. Walker wrote: > >>> BERTRAND Joël wrote: > >>>> BERTRAND Joël wrote: > >>>>> I can format serveral times (mkfs.ext3) a 1.5 TB volume > >>>> over iSCSI > >>>>> without any trouble. I can read and write on this virtual > >>>> disk without > >>>>> any trouble. > >>>>> > >>>>> Now, I have configured ietd with : > >>>>> > >>>>> Lun 0 Sectors=1464725758,Type=nullio > >>>>> > >>>>> and I run on initiator side : > >>>>> > >>>>> Root gershwin:[/dev] > dd if=/dev/zero of=/dev/sdj bs=8192 > >>>>> 479482+0 records in > >>>>> 479482+0 records out > >>>>> 3927916544 bytes (3.9 GB) copied, 153.222 seconds, 25.6 MB/s > >>>>> > >>>>> Root gershwin:[/dev] > dd if=/dev/zero of=/dev/sdj bs=8192 > >>>>> > >>>>> I'm waitinfor a crash. No one when I write these lines. > >>>> I suspect > >>>>> an interaction between raid and iscsi. > >>>> I simultanely run : > >>>> > >>>> Root gershwin:[/dev] > dd if=/dev/zero of=/dev/sdj bs=8192 > >>>> 8397210+0 records in > >>>> 8397210+0 records out > >>>> 68789944320 bytes (69 GB) copied, 2732.55 seconds, 25.2 MB/s > >>>> > >>>> and > >>>> > >>>> Root gershwin:[~] > dd if=/dev/sdj of=/dev/null bs=8192 > >>>> 739200+0 records in > >>>> 739199+0 records out > >>>> 6055518208 bytes (6.1 GB) copied, 447.178 seconds, 13.5 MB/s > >>>> > >>>> without any trouble. > >>> The speed can definitely be improved. Look at your network setup > >>> and use ping to try and get the network latency to a minimum. > >>> > >>> # ping -A -s 8192 172.16.24.140 > >>> .... > >>> --- 172.16.24.140 ping statistics --- > >>> 14058 packets transmitted, 14057 received, 0% packet loss, time 9988ms > >>> rtt min/avg/max/mdev = 0.234/0.268/2.084/0.041 ms, ipg/ewma 0.710/0.260 ms > >> gershwin:[~] > ping -A -s 8192 192.168.0.2 > >> PING 192.168.0.2 (192.168.0.2) 8192(8220) bytes of data. > >> 8200 bytes from 192.168.0.2: icmp_seq=1 ttl=64 time=0.693 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=2 ttl=64 time=0.595 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=3 ttl=64 time=0.583 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=4 ttl=64 time=0.589 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=5 ttl=64 time=0.580 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=6 ttl=64 time=0.594 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=7 ttl=64 time=0.580 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=8 ttl=64 time=0.592 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=9 ttl=64 time=0.589 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=10 ttl=64 time=0.571 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=11 ttl=64 time=0.588 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=12 ttl=64 time=0.580 ms > >> 8200 bytes from 192.168.0.2: icmp_seq=13 ttl=64 time=0.587 ms > >> > >> --- 192.168.0.2 ping statistics --- > >> 13 packets transmitted, 13 received, 0% packet loss, time 2400ms > >> rtt min/avg/max/mdev = 0.571/0.593/0.693/0.044 ms, ipg/ewma 200.022/0.607 ms > >> gershwin:[~] > > >> > >> Both initiator and target are alone on a gigabit NIC (Tigon3). On > >> target server, istd1 takes 100% of a CPU (and only one CPU, even my > >> T1000 can simultaneous run 32 threads). I think the limitation comes > >> from istd1. > > > > usually istdx will not take 100% cpu with 1G network, especially when > > using disk as back storage, some kind of profiling work might be helpful > > to tell what happened... > > > > forgot to ask, your sparc64 platform cpu spec. > > Root gershwin:[/mnt/solaris] > cat /proc/cpuinfo > cpu : UltraSparc T1 (Niagara) > fpu : UltraSparc T1 integrated FPU > prom : OBP 4.23.4 2006/08/04 20:45 > type : sun4v > ncpus probed : 24 > ncpus active : 24 > D$ parity tl1 : 0 > I$ parity tl1 : 0 > > Both servers are built with 1 GHz T1 processors (6 cores, 24 threads). > as Ross pointed out, many io pattern only have 1 outstanding io at any time, so there is only one work thread actively to serve it. so it can not exploit the multiple core here. you see 100% at nullio or fileio? with disk, most time should spend on iowait and cpu utilization should not high at all. > Regards, > > JKB -- Ming Zhang @#$%^ purging memory... (*!% http://blackmagic02881.wordpress.com/ http://www.linkedin.com/in/blackmagic02881 -------------------------------------------- - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
