Well, unless I mistake its shape and making quite, it is that shrewd and knavish sprite of an iSCSI implementation on Linux. There's a couple of potential problems here, so I'll go through some diagnostic stuff step by step: -Are you using a hardware iSCSI card? Our internal testing here at gridapp shows that a dual-cpu host can push roughly (very roughly!) 40 MB/sec. of I/O over a dedicated gige link without hardware offload. -What is the CPU utilization like on your host side while this I/O is happening? -How large are the volumes on the filer side that the luns are being presented off of? sysconfig -r will show this -Also, look at the disk utilization on the filer side. use the priv set advanced command, followed by statit -b (wait a minute or so during a period of heavy i/o) then run statit -e. Take a look at the data you get back from the filer? -Jumbo frames? That should be a requirement. -Also, iostat on linux is known to lie, especially with nonstandard block devices - are you actually seeing performance problems? The iostat does show a _lot_ of I/O. -Finally, why iSCSI? Why not just use nfs? -What type of filer? You can respond to me directly if you like - unless the list at large is interested in iSCSI on netapp. Thanks, Matt -- Matthew Zito GridApp Systems Email: mzito@xxxxxxxxxxx Cell: 646-220-3551 Phone: 212-358-8211 x 359 http://www.gridapp.com On Apr 28, 2004, at 8:10 PM, Sai Selvaganesan wrote: > hi > > the following is the o/p of iostat on a new configured machine with > netapp filer over icsci running oracle 9i database(1 tb in size). > > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz > await svctm %util > sda 807.31 2.99 252.82 1.33 8486.38 34.55 33.53 8.50 > 33.07 5.23 13.29 > sda1 807.31 2.99 252.82 1.33 8486.38 34.55 33.53 8.50 > 33.07 5.23 13.29 > sdb 2791.03 0.33 1055.81 3.99 30790.70 34.55 29.09 44.12 > 41.13 8.03 85.05 > sdb1 2791.03 0.33 1055.81 3.99 30790.70 34.55 29.09 44.12 > 41.13 8.03 85.05 > sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > 0.00 0.00 0.00 > sda 6446.67 3.00 1444.00 1.33 63122.67 34.67 43.70 91.73 > 63.49 6.90 99.67 > sda1 6446.67 3.00 1444.00 1.33 63122.67 34.67 43.70 91.73 > 63.49 6.90 99.67 > sdb 2137.67 0.33 587.33 2.33 21826.67 21.33 37.05 32.13 > 54.78 13.23 78.00 > sdb1 2137.67 0.33 587.33 2.33 21826.67 21.33 37.05 32.13 > 54.78 13.23 78.00 > sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > 0.00 0.00 0.00 > sda 682.67 2.00 201.67 1.33 7080.00 34.67 35.05 14.90 > 73.23 14.61 29.67 > sda1 682.67 2.00 201.67 1.33 7080.00 34.67 35.05 14.90 > 73.23 14.61 29.67 > sdb 11828.67 0.00 2243.33 1.67 112573.33 13.33 50.15 125.23 > 55.68 4.45 > 100.00 > sdb1 11828.67 0.00 2243.33 1.67 112573.33 13.33 50.15 125.23 > 55.68 4.45 100.00 > sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > 0.00 0.00 0.00 > sda 1878.33 3.00 480.33 1.00 18864.00 32.00 39.26 36.10 > 75.07 20.43 98.33 > sda1 1878.33 3.00 480.33 1.00 18864.00 32.00 39.26 36.10 > 75.07 20.43 98.33 > sdb 11763.33 0.00 1908.00 1.00 109365.33 8.00 57.29 > 129.90 68.20 5.24 100.00 > sdb1 11763.33 0.00 1908.00 1.00 109365.33 8.00 57.29 > 129.90 68.20 5.24 100.00 > sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 > 0.00 0.00 0.00 > > i have bolded the avrg wait,srvc time and % utilization and i think > given the above stats the i/o is bad on this configuration. the wait > times are very high and there is a problem with the way physical > configuration of the disks is done and how the datafiles are laid out. > > please advise me on this and explain whether my observation is > alright. and also tell me what could be a reason for this to happen. > > thanks > sai > > ---------------------------------------------------------------- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > ---------------------------------------------------------------- > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > put 'unsubscribe' in the subject line. > -- > Archives are at //www.freelists.org/archives/oracle-l/ > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------