Jumbo frame confusion.

[Muhammad Yousuf Khan]

My freeNAS configuration is.
22GB RAM.
ZFS Mirror 2x1GB Sata 7200RPM drives.
2x3.0Ghz Xeon processors.
Intel 4 port LANCard.
Brand: Dell precision 490

Linux system for visualization. detail is.
12GB RAM.
OS Linux Debian Wheezy
Single Sata 7200 RPM Drives Drive
2x3.0Ghz Xeon processors.
Intel 4 port LANCard.
Brand: Dell precision 490


Both systems are connected Back to back with Crossover cable. and NFS share is enabled. Jumbo frames (9000) are enabled and tested via Ping.

below is the test result in following traffic format.
freenas ------6gb-file---> Linux Server.

when i rsync --progress a big file of 6GB. for first 25% of data transfer it gives me 70MB 80MB then it decreases to 49MB to 54MB until transfer completed.
so my question is why it first give it is giving me 80MB then decline to 50MB. what could be the reason. ?
actually where you guyz see bottleneck.

LinuxServer--------6gb-File-----> FreeNAS
it gives me average of 41MB.

so my question is with out jumbo and with jumbo the performance is almost same. so am i mistaken some where or jumbo frames are almost useless. i should turn it back to MTU 1500?

Thanks,
MYK

 

[DrKK]

Jumbo frames are almost useless. The risks of using them far outweigh the benefits.

 

[Ericloewe]

Jgreco discussed jumbo frames just the other day.

 

[Muhammad Yousuf Khan]

If i need 1GB LAN throughput what are the minimum hardware requirements?

do you guys think Increasing the RAM and installing SAS will help? or my system specs are enough for 1GB throughput i just need to tweak the settings?

people say we normally do not need ZIL and Log drives. but they also say it increase the performance. can anyone explain what is the point where i should install ZIL and LOG drives.

Thanks Ericloewe i will read that seems informative.

 

[DrKK]

Sir:

Do you mean 1 gigaBIT throughput, or 1 gigaBYTE throughput, because that's a CONSIDERABLE difference in price.

 

[Muhammad Yousuf Khan]

sorry for the Capital "B" i meant bit "b".

 

[Ericloewe]

Cyberjock goes over L2ARC and SLOG devices in his guide (link in my sig).

 

[jgreco]

Jgreco discussed jumbo frames just the other day.

Although in a back-to-back direct connection, some of the meta-issues that plague jumbo vanish.

Linux system for visualization.

Visualization or virtualization? There's a hell of a difference.

My freeNAS configuration is.

ZFS Mirror 2x1GB Sata 7200RPM drives.

Anyways, mirror is good but your pool size in terms of the number of spindles is very small. Further, with NAS, your overall performance is a result of the layering of a bunch of complex subsystems on them. Not only is the NAS limited by the weakest of these (guessing: the actual disks in your case), but also those weaknesses tend to get amplified through the other layers.

That's not saying that this is what your problem is, but I'm saying that the weakest bit of your NAS is probably the disk itself.

 

[Muhammad Yousuf Khan]

i had installed a single SSD drive. along side current ZFS. so the SSD is also a new ZFS disk but single now when i copy and paste it almost give me the same result. which i am expecting higher because SSDs are more faster then SATA. now what could be the issue.