Got a chance to test out the latest EON version.
Along with test the new version I added another GB of RAM to my server. The Marvell driver detected and configured my network cards just fine. My first couple of file copies (same test files I used before) to the server averaged around 80-85 MB/sec with just a single drive which was a good improvement over my previous tests. After this I deleted the files I copied and tried writing them again and realized that now I was seeing the network spikes/stalls again. Did some read tests and those were about the same speed as before at around 60 MB/sec.
So all of this got me wondering what is causing the network stalls. I recall running into a similar problem using Win XP PRO on the server and coping files to a disk on the server that is much slower than the one on the client. For example I am blasting a file across the network at 100 MB/sec but the disk being written to can only write at 50 MB/sec. If the server only has around 512 MB of RAM I would most likely only be able to buffer a total of 400 MB before running out of memory. At that point the file transfer would stall until some of the buffered data could be written to the disk. Then once there was a bit of room the transfer would resume again. In some cases when the transfer resumes the OS throttles transfer speed to match the actual speed the data can be written to the disk. Other times the transfer resumes at max speed and then ends up stalling the file transfer again and again. My thought was maybe this was happening to me on EON.
I used the diskspeed.sh command to check disk speeds and that came back at 115 MB/sec for the disk in question. Then I decided to test actual read/write speeds using dd. I timed how long it took to complete this command dd if=/dev/zero of=/thing/test bs=1048576 count=1000. Which should write a 1000 MB file to my disk. Time was 26 seconds. 1000/26 = 38.46 MB/sec. Then I timed how long it took to complete this command dd if=/thing/test of=/dev/null. Which should read that same file. Time was 24 seconds. 1000/24 = 41.66 MB/sec. Now these tests were done after I noticed the lower file transfer speeds. During my first couple of file transfers I used "zpool iostat 1" to view write speeds and it was consistantly around 100 MB/sec. Based on these weird results I think that my disk controller might not be working correctly in EON. What do you think?
00Roush
Along with test the new version I added another GB of RAM to my server. The Marvell driver detected and configured my network cards just fine. My first couple of file copies (same test files I used before) to the server averaged around 80-85 MB/sec with just a single drive which was a good improvement over my previous tests. After this I deleted the files I copied and tried writing them again and realized that now I was seeing the network spikes/stalls again. Did some read tests and those were about the same speed as before at around 60 MB/sec.
So all of this got me wondering what is causing the network stalls. I recall running into a similar problem using Win XP PRO on the server and coping files to a disk on the server that is much slower than the one on the client. For example I am blasting a file across the network at 100 MB/sec but the disk being written to can only write at 50 MB/sec. If the server only has around 512 MB of RAM I would most likely only be able to buffer a total of 400 MB before running out of memory. At that point the file transfer would stall until some of the buffered data could be written to the disk. Then once there was a bit of room the transfer would resume again. In some cases when the transfer resumes the OS throttles transfer speed to match the actual speed the data can be written to the disk. Other times the transfer resumes at max speed and then ends up stalling the file transfer again and again. My thought was maybe this was happening to me on EON.
I used the diskspeed.sh command to check disk speeds and that came back at 115 MB/sec for the disk in question. Then I decided to test actual read/write speeds using dd. I timed how long it took to complete this command dd if=/dev/zero of=/thing/test bs=1048576 count=1000. Which should write a 1000 MB file to my disk. Time was 26 seconds. 1000/26 = 38.46 MB/sec. Then I timed how long it took to complete this command dd if=/thing/test of=/dev/null. Which should read that same file. Time was 24 seconds. 1000/24 = 41.66 MB/sec. Now these tests were done after I noticed the lower file transfer speeds. During my first couple of file transfers I used "zpool iostat 1" to view write speeds and it was consistantly around 100 MB/sec. Based on these weird results I think that my disk controller might not be working correctly in EON. What do you think?
00Roush
