Download/Upload Performance Issues Since 1.1.2
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[quote=“ianabc, post: 31746, member: 24548”]Is this is a raw copy over NFS? If not could you try a copy and report the speed? 75MB/s is in the right ballpark for gigabit over NFS.[/quote]
yeah, 75MB a second is pretty fast. Sorry I mis-interpretted it as 75MB/min.
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Changed the compression and re-uploaded: no change.
Finally was able to check the NFS transfer speed: I had 26 MB/sec transferring to and from one VM to the FOG server. Apparently my 75 MB/sec was my transfer speed to/from the FOG server to the iSCSI disk.
So I’m left puzzled about what happened between now and then. I did some Ubuntu updates too.
Guess I have something to be puzzled about over the weekend.
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The iSCSI speed sounds plausible for a single GigE link, but the NFS does indeed seem slow.
If there was a 100Mb link somewhere you would expect to see 7MB/s or so and as you said everything is claiming to be running GigE. 26MB/s is an odd result, especially if that is bi-directional. Can I ask how you are testing? dd over NFS can help but it can be a bit tricky because of the buffering and syncing.
Did you try Tom’s suggestion of switching out the kernel for a test.
Have a fun weekend!
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Here is a sample NFS mount from a linux client - in principle it should all be GigE between the fog server and this machine, but they are quite a few hops apart and those switches and routers might be busy, could you try something similar for comparison?
[CODE]
$ mkdir /fogtest
$ mount -o vers=3,nolock IP.OF.YOUR.FOG:/images/dev /fogtest
$ dd bs=1M count=1024 if=/dev/zero of=zeros.img conv=fdatasync
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied 30.5422 s, 35.2 MB/s$ dd bs=1024M if=./zeros.img of=/dev/null iflag=direct
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied 21.0712 s, 51.0 MB/s$ rm zeros.img
$ umount /fogtest
$ rmdir /fogtest
[/CODE]
I’m not too worried (or impressed :)) by these numbers. If you get similar results you know that the problem lies further up the stack. -
Finally got around to the testing this using your test, here’s my results:
[CODE]$/media/test$ sudo dd bs=1M count=1024 if=/dev/zero of=zeros conv=fdatasync
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 26.2786 s, 40.9 MB/s
$/media/test$ sudo dd bs=1M count=1024 if=/dev/zero of=zeros conv=fdatasync
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 24.3489 s, 44.1 MB/s
$/media/test$ sudo dd bs=1M count=1024 if=/dev/zero of=zeros conv=fdatasync
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 23.3077 s, 46.1 MB/s
$/media/test$ dd bs=1024M if=zeros of=/dev/null1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 12.7035 s, 84.5 MB/s
$/media/test$ dd bs=1024M if=zeros of=/dev/null
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 12.5741 s, 85.4 MB/s
$/media/test$
$/media/test$ dd bs=1024M if=zeros of=/dev/null
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 12.9285 s, 83.1 MB/s
$/media/test$ dd bs=1024M if=zeros of=/dev/null
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB) copied, 13.0684 s, 82.2 MB/s
[/CODE]I was completely perplexed with this issue. It almost seems like an update to 12.04 is causing this, because I updated Ubuntu 12.04 around the same time as upgrading FOG.
Other things I’ve tried that have zero changes:
[LIST]
[]Changing the kernel
[]Making sure /etc/exports has async
[]Changed the switch
[]Loaded FOG 1.0.1 on the iSCSI target and ran FOG from that
[/LIST]
Then, it suddenly occurred to me: I haven’t tested the server on a different machine.(Facepalm)
I ran FOG on a completely different system/image, but one with comparable image size, and voila – speeds are back.
So here’s what I think the problem is: the laptops I was imaging – [U][URL=‘http://support.lenovo.com/en_US/product-and-parts/detail.page?DocID=PD030723’]Thinkpad Edge E540[/URL][/U] – runs one of these ethernet controllers: [SIZE=12px][FONT=Arial][COLOR=#000000]Realtek RTL8111/8168/8411 PCIe GBE Ethernet Controller, and [/COLOR][/FONT][/SIZE][U][SIZE=12px][FONT=Arial][COLOR=#000000][URL=‘http://forums.linuxmint.com/viewtopic.php?f=49&t=152180’]they [/URL][/COLOR][/FONT][/SIZE][/U][U][URL=‘http://forums.linuxmint.com/viewtopic.php?f=49&t=152180’]seem to have an issue with running at 100 Mbit even though it’s a gigabit interface[/URL][/U]. This correlates with my experience and the speeds that I was getting on those machines.
Perhaps, then, the kernels need an update to include those drivers? I’m not sure, but at the very least I wanted to report my findings.
PS- I think the hyperlink color should change, or at least add an underline like below. One word links seem to blend-in too well.
Also, thanks again for all the help.
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The kernel’s I’ve been building for quite some time have these drivers included already.
Otherwise, they wouldn’t work at all.
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[quote=“Tom Elliott, post: 31960, member: 7271”]The kernel’s I’ve been building for quite some time have these drivers included already.
Otherwise, they wouldn’t work at all.[/quote]
Maybe there’s a problem with the Linux driver? Windows doesn’t seem to have the 100 Mbps problem that I had. The issue only appeared in FOG.
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This is really puzzling, I’ll dig around and see if I have one of those cards available for testing. I think you already checked this, but could you confirm that in the fog debug ethtool reports 1000Mb as the negotiated speed and that you switch also agrees that this is the negotiated speed?
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[quote=“ianabc, post: 31998, member: 24548”]This is really puzzling, I’ll dig around and see if I have one of those cards available for testing. I think you already checked this, but could you confirm that in the fog debug ethtool reports 1000Mb as the negotiated speed and that you switch also agrees that this is the negotiated speed?[/quote]
I no longer have them here to test, but I can say for certain that that they auto-negotiated to gigabit. Even the switch was reading the speed as gigabit.
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i’ve heard of problems with some cards, that they have a power setting (configurable from windows) that will drop to 100m in low power mode, and may not come back out of it and into 1000m when booting into linux. but when booted into windows, they come back up to full speed. if you disable that setting in windows, the problem goes away completely.
