Varying transfer rates

[danakajoel]

Hi, I've recently installed Freenas on an HP Proliant N40L with 2gb ram. It currently has 1x1TB disk which I set up as a ZFS volume. I've set up some CIFS shares and ZFS datasets.

What I've found is that at times I can move data between the shares (which are all on the same drive) with no problems. Then at other times, when I try and move data around it only does so at 1mb per second. Does anyone know what could be causing the intermittent slow down in transfer rates? I've also tried copying files from the shares to my computer and still only get 1mb/sec.

Any help appreciated.

 

[danakajoel]

Is no-one able to help. It's a very frustrating problem and I can't see the answers in the FAQ's. Would I need to change any BIOS settings before using Freenas? Could the drive be dying?

 

[Pierremenard]

I'm a very noob of ZFS/Freenas, but maybe you should clarify how you are moving files between the shares/datasets.

If you do it from a second computer the speed of course will be degraded depending on network (even more if data are on 2 different datasets).

The best way is to move data is through shell (ssh or directly on freenas server) with mv command or rsync (--remove-source-files). I don't know why, mv command sometimes (with big files) hangs my system, I prefer using rsync that it's less performant but gives you a progress in the moving (using the -aP switch).

Bye

F.

 

[danakajoel]

Thanks for the reply. I have one disk in the drive in my server and was attempting to move the files using the web interface. As it's only 1 drive in the server, I'd have thought it would be near instant to move files between dataset shares. Instead it tops out at 1mb/sec. I simply don't understand this???

 

[wussy]

Hi,
2GB is really low memory.MAybe you read in the handbook what is written there for RAM: http://doc.freenas.org/index.php/Hardware_Requirements
In my opinion it´s a RAM problem. You can test out the transfer speeds when using UFS to see what´s the different.

You also may take a look at your memory utilization. Is it fully utilized?

What Freenas version you are using?
What are your hardware specs?
What is your networking hardware?

Best regards

 

[wussy]

Thanks for the reply. I have one disk in the drive in my server and was attempting to move the files using the web interface. As it's only 1 drive in the server, I'd have thought it would be near instant to move files between dataset shares. Instead it tops out at 1mb/sec. I simply don't understand this???

This isn´t right at all. When you are copying over CIFS it will take the way over your computer and not directly. Also when you copy directly on the shell there will be an overhead.
To get the speed from your harddisc you can check this:
Write
dd if=/dev/zero of=/mnt/store/tmp.dat bs=2048k count=50k
Read:
dd if=/mnt/store/tmp.dat of=/dev/null bs=2048k count=50k

But again in my opinion the ram is the problem.

 

[danakajoel]

Hi,
2GB is really low memory.MAybe you read in the handbook what is written there for RAM: http://doc.freenas.org/index.php/Hardware_Requirements
In my opinion it´s a RAM problem. You can test out the transfer speeds when using UFS to see what´s the different.

You also may take a look at your memory utilization. Is it fully utilized?

What Freenas version you are using?
What are your hardware specs?
What is your networking hardware?

Best regards

I had considered a ram problem but the memory usage normally appears to be minimally utilized. I hadn't realized it was slow as CIFS move to my computer first. Was the script you posted something i'd enter in to Putty, I am fairly new with these things. What result would I be looking for? Thanks.

My specs are:

Freenas 8.0.4 (running from 8gb USB)
HP Proliant N40L
AMD Turion™ II Neo N40L (1.5GHz)
2gb RAM
1 x 1TB harddrive on ZFS.

 

[wussy]

Yeah you have to enter it in putty.

Change the /mnt/store/ to your dataset name: dd if=/dev/zero of=/mnt/YOURDATASETNAME/tmp.dat bs=2048k count=50k
You can have a look at all mounts when you go to /mnt with putty.
There is a thread where people post the results of these tests and you can compare them to your speed:http://forums.freenas.org/showthread.php?981-Notes-on-Performance-Benchmarks-and-Cache

Should the system really not utilize the RAM you can set some parameters under the tune tables. Read here for more infos : http://forums.freenas.org/showthread.php?6207-ZFS-memory-tuning&highlight=vfs.zfs.arc_max

Are you running the 32bit or the 64bit version?

 

[danakajoel]

I am running the 64 bit version. I am fairly new to all this but luckily somebody in my office is fairly savy. I have been trying to move the data between CIFS shares that appear on my Windows laptop which is wireless. He's pointed out that the data first has to get to my laptop and then back to the server which is very slow over Wifi and would likely explain my 1mb/s speed. He's suggested setting up an SCP connection and doing the moves that way so I'll test this week and report back. He also said FTP should work.

Thanks for the links, I'll look at those as well.

 

[wussy]

I think WinSCP will copy direct but i´m not sure about it. the question is what you are trying to prove with that. When it´s only to show the disk speed, you can use the dd command.
But the really interesting thing is how fast is the NAS when connecting by CIFS or something like this.

Also that there´s only one disc does´t make sense to me.
MAybe you tell us what the aim of this is?!

 

[danakajoel]

I set it up to test Freenas. I have two other 1TB drives about to go in there, however, I am holding fire until I understand these teething problems.

 

[wussy]

Okay but be aware that your RAM won´t be enough for sure. Maybe is better to play around with the full setup because then you can see what the real problems are.
If you need any help don´t hasitate to ask.