Slow NAS, NOOB!!!

[agentsmith23]

So I built a new PC and setup my old one to use FreeNAS. I have everything talking to each other but the transfer rates seem much slower than expected. I am seeing only about 2-3MBps over wireless N and on a hardwired connection about 5MBps. For the hardware I am using an AMD Athlon 7850, 4GB RAM, 320GB SATA 7200 RPM HDD (not much storage I know but this is just a test run to see if this will be a viable option for me) also the NIC is Gb and has LEDs on the back to indicate the mode it is in and it indicates that it is in Gb mode. As far as FreeNAS goes I haven't done much, just setup a basic CIFS share following the FreeNAS user guide.

I have been doing a bit of testing on my end to figure out what is going on and I am stumped. I have ran iperf and it is showing between 18-20Mbps transfer speeds. This result came from a wireless N Windows 7 desktop wireless signal strength is good and shows 108Mbps constant connection.

From the user guide I also enabled "Large RW support", "Send files with sendfile(2)", and "Enable AIO" none of these options made a difference in performance. I have also read others having this similar issue get great throughput on ftp, so I setup ftp and once again I got about the same bandwidth.

Let me know if more info is needed? What else should I be checking?

 

[joeschmuck]

First thoughts... That is not a speedy CPU. Are you running the drive formatted as ZFS? If so, for your specific configuration I would suggest you change to UFS. You don't mention which version of FreeNAS you are running either or your motherboard. I'm not focused in on the wireless but the wired connection should be better than 5MB/sec. How are you testing the transfer speed? Please don't say it's a ton of small files. If you want to transfer files, use a large file, 600MB or larger.

-Joe

 

[agentsmith23]

I know the CPU isn't top of the line but a 2.8GHz dual core should be fine for this am I wrong? If this is inadequate, what is the minimum processor to get good bandwidth? I am running FreeNAS-8.0.2-RELEASE-amd64 (8288) the motherboard is a Gigabyte MA78GM-US2H and the drive is formatted in ZFS. I just read over the system requirements again and apparently my weak point would probably be the RAM "ZFS typically requires a minimum of 6 GB of RAM in order to provide good performance". Didn't even look at the ram requirements before just assumed 4GB would be adequate. As far as my tests go I was using iperf and for real world tests I was just using a folder with 15GB of data a mix of large and small files.

 

[agentsmith23]

Switched over to UFS and noticed an improvement over wireless. My speeds are now around 9-12MBps, I will check wired in a bit and check back in.

 

[agentsmith23]

Well apparently the whole issue came from using ZFS, hardwired with a confirmed Gb connection got 50-75MBps. Still curious about my hardware, is it just my RAM that would need to be upgraded to allow me to use ZFS and eliminate the bottleneck or is my processor part of the cause also? If the processor is causing it also what AMD AM2+ or AM3 processor would be the bare minimum?

One other thing I noticed, if I have multiple file transfers going wirelessly I get a combined throughput of about 18MBps. Why don't I see that type of throughput when dealing with a single file?

 

[Milhouse]

With only 4GB RAM, you'll have ZFS read-ahead disabled by default, try enabling read-ahead by adding "vfs.zfs.prefetch_disable=0" to /boot/loader.conf - it should significantly improve your disk IO read performance (perhaps 3x-4x). If you upgrade to more than 4GB RAM, eg. 5GB or preferably 8GB, then prefetch will not be disabled by default.

As for minimum CPU, users of HP N36L Microservers have no problems with ZFS, and the N36L uses a dual-core 1.3GHz AMD Neo (based on the old Athlon 64, and today circa Atom-class), so your current CPU is absolutely fine. Better than fine, in fact, so I highly doubt your CPU is the issue.

 

[joeschmuck]

I think you only have two problems, 1) the prefetch as Milhouse indicated (for ZFS) and 2) I wouldn't recommend a single ZFS drive configuration if speed is a factor for you. And I'm only speaking for myself and from my personal observations. I'm not a super savvy FreeNAS expert but Milhouse is.

As for multiple files raising the throughput, I can't answer that, sounds odd to me but I don't use wireless N so I can't test that out. Your hardwired connection sounds reasonable to me in general, I would think it be a little higher under UFS but I don't have your specific hardware configuration to see what might be limiting your transfer speed. But still the wired is not bad at all.

 

[agentsmith23]

I am probably going to be sticking with UFS for now. I have been doing more testing while transferring all my data. All of my testing has been from my main PC with both a wired and wireless connection. With wireless like I mentioned before if I have more than one transfer going at a time it seems to add onto the previous transfer until I max out around 18-20MBps and those transfers are basically large transfers of a bunch of smaller files like photos, videos and audio. Each individual transfer wirelessly with a large volume of smaller files usually 1-20GB will generally get 5-8MBps after it stabilizes, when it usually starts the transfer the rate can be as high at 20MBps but gradually drops and stabilizes in that range. Any idea what would cause that? Wired transfers behave similar for the speed starting high then stabilizing much lower, they usually start around 30-50MBps for a large group on smaller files, for example as I type this message I am transferring 33,608 pictures 96.2GB it started around 35MBps but has stabilized around 20MBps generally fluctuating between 19-21MBps. While waiting for the transfer to finish I noticed the speed continues to drop it is now at 17MBps and eventually finished at 15MBps. I tried starting a second transfer to see if the combined transfer rate would increase like with wireless but it just gave them both around 10MBps. Any idea what would cause this? And the wired connection if I just transfer one large file like a 4GB DVD iso I get generally around 60MBps.

What would cuase these iperf tests to be so low, windows indicates my wired connection is Gb and wireless is 300Mb, my router confirms 300Mb for wireless as well.


iperf -c 192.168.1.140 -t 60 -i 10
------------------------------------------------------------
Client connecting to 192.168.1.140, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[160] local 192.168.1.110 port 54247 connected with 192.168.1.140 port 5001
[ ID] Interval Transfer Bandwidth
[160] 0.0-10.0 sec 395 MBytes 332 Mbits/sec
[160] 10.0-20.0 sec 382 MBytes 320 Mbits/sec
[160] 20.0-30.0 sec 385 MBytes 323 Mbits/sec
[160] 30.0-40.0 sec 390 MBytes 327 Mbits/sec
[160] 40.0-50.0 sec 382 MBytes 321 Mbits/sec
[160] 50.0-60.0 sec 379 MBytes 318 Mbits/sec
[160] 0.0-60.0 sec 2.26 GBytes 323 Mbits/sec



iperf -c 192.168.1.140 -t 60 -i 10
------------------------------------------------------------
Client connecting to 192.168.1.140, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[160] local 192.168.1.142 port 54321 connected with 192.168.1.140 port 5001
[ ID] Interval Transfer Bandwidth
[160] 0.0-10.0 sec 27.9 MBytes 23.4 Mbits/sec
[160] 10.0-20.0 sec 29.1 MBytes 24.4 Mbits/sec
[160] 20.0-30.0 sec 27.9 MBytes 23.4 Mbits/sec
[160] 30.0-40.0 sec 28.1 MBytes 23.6 Mbits/sec
[160] 40.0-50.0 sec 26.1 MBytes 21.9 Mbits/sec
[160] 50.0-60.0 sec 27.8 MBytes 23.3 Mbits/sec
[160] 0.0-60.0 sec 167 MBytes 23.3 Mbits/sec

Generally I will be staying with wireless connections except for when I am doing rather large transfers.