With GREAT Hope once again i am trying to get a reply from the experts... (with few more test results in other info section) Techies, I am a newbie to iscsi and just started to test different scenarios for one of our requirement. I had different testing on CentOS 6, but in both i didnt get the expected performance. In the first test it was just 40 MB/s and in the second it was just 50 MB/s. The details are as follows; Test 1: Initiator: OS: CentOS 6 64 bit with tgt initiator package: iscsi-initiator-utils-6.2.0.872-10.el6.x86_64 Server: Gateway GR 180 F1 CPU: Intel(R) Xeon(R) CPU E5506 @ 2.13GHz ( Quad Core ) RAM: 6 GB Disks: WD 1 TB 7200 RPM NIC: Gigabit Target: OS: CentOS 6 64 bit with tgt target package: scsi-target-utils-1.0.4-3.el6_0.1.x86_64 Server: Gateway GR 180 F1 CPU: Intel(R) Xeon(R) CPU E5506 @ 2.13GHz ( Quad Core ) RAM: 6 GB Disks: WD 1 TB 7200 RPM NIC: Gigabit other infos: a. from target, 6 disks is exported through the tgt iscsi (raw disks, i mean there is no any filesystem) as direct store. b. from initiator 6 disks is connected by iscsiadm c. in initiator these 6 disks is configured with ZFS as a raidz (raid 5) volume d. ran the "iozone" and "dd" tests almost for 10 times. in both cases i got the performance in between 37 MB/s to 44 MB/s (i didnt find any diff in both commands, sometimes it goes as low to 37 MB/s and the maximum to 44 MB/s) e. while monitoring the network speed (using iftop), i can see the transfer speed is almost steady around 300 - 350 Mbps network speed related info: a. i tested with "iperf" and "ttcp" and got a steady speed of 920 Mbps. Test 2: Same Target and Initiator h/w and software configuration other infos: a. in target i configured a raid 5 device (/dev/md0) with 3 disks and then exported /dev/md0 as backing-store through tgt iscsi (without any filesystem) b. from initiator /dev/md0 (riad disk @ target) disk is connected by iscsiadm c. in initiator, i created a small partition of 25 GB in the RAID5 device and then formatted with ext3 and then mounted to a directory d. ran the "iozone" and "dd" tests almost for 10 times. in both cases i got the performance in between 48 MB/s to 52 MB/s (i didnt find any diff in both commands, sometimes it goes as low to 48 MB/s and the maximum to 52 MB/s) e. while monitoring the network speed (using iftop), i can see the transfer speed varies highly in between 300 Mbps to 700 Mbps. f. while tested by connecting to the loopback interface (127.0.0.1), i got a small hike in performance which is 60 MB/s g. when i tried just with 3 disks in the zfs pool (instead of 6 disk set in zfs raidz), the performance again slower, which is only 35 MB/s h. when i transfered to a local zfs pool (no iscsi), the performance was really good, which was up to 170 MB/s. i. when i checked with 3 disks set + zfs raidz with scst iscsi (took almost 3 days to configure scst), got 50% hike in the speed and reached up to 52.2 MB/s (when compared to 35 MB/s in stgt with 3 disk set), which is still low performance in a Gigabit environment (which i think so). My questions are; 1. What is the regular speed of stgt iscsi in such and hardware and software environment. 2. why i am getting this much slow performance 3. how can i increase my iscsi performance. 4. Which is the best distro and its version, in which tgt iscsi will perform very well (i am going to test with Debian and Ubuntu too) 5. As i am trying to build a storage solution for our production environment, is this way of proceeding is good. i mean the combination of centos+tgt iscsi is a dependable solution? 6. Do anybody had any advices/suggestions to make our effort succesful as a home made storage solution for our production environment. Expecting all of your kind support and co-operation Thanks in Advance :) -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
