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[GIS_Kid]

I've searched the forums, and found other threads pertaining to similar issues... but none seem to be as slow as 8 mbps over a gigabit lan... this seems super slow!  Are these the speeds that I can expect, or could there be an issue?  I've got a dlink gigabit router and nforce gigabit lan...

core 2 duo 3ghz
4 gigs of ram
fast sata drives...

Please point me in the right direction

[bomberbrown]

I was gonna post a similar question, but since you started it.  I thought my 10mbps to 12mbps was bad, but yours is worse   

For info, this is my hardware and the data path (PC to DNS-323) - Samsung 1Tb Sata HD (internal) > Gig network adapter on a Shuttle PC running Vista > Dlink DIR-615 Gigabit Router > DNS-323 Raid1 with 2 Samsung 1Tb Sata HD (internal)

fw 1.06

[fordem]

Are we discussing megabits per second here, or megabytes per second?

8, 10 or 12 - if that is megabits per second, it's ridiculously slow - if it's megabytes second, it's reasonable.

First - a gigabit network does not guarantee gigabit throughput, especially when you're measuring file transfer speeds (as compared to network throughput speeds).

A file transfer starts on one disk and finishes on another - the speed is going to limited to the slowest of the interfaces, and is also affected by things like disk fragmentation and file size - transferring 2GB of data can be dramatically different when you compare a single 2GB file to 1000 x 2MB files.

Now - this is a topic that has been discussed adnauseum - a search of the forum should bring up several threads, including links to file transfer and I believe network speed testers.

[GIS_Kid]

Thanks for the reply.  I was indeed speaking in megabytes per second.  I should have come to these forums prior to purchase.  If I had known the speeds would be this unbelievably brutal, I wouldn't have bought the unit.  I'm not sure where else I can use my 2 tb drives if I return this thing. 

I was assuming I'd be achieving speeds similar to those I get on my corporate lan.  I guess I was wrong.

as for your comment:
"Now - this is a topic that has been discussed adnauseum - a search of the forum should bring up several threads, including links to file transfer and I believe network speed testers."

as I mentioned, I DID do a search of the forums and found some similar threads.  They didn't seem to answer my question. But thanks for your admonishment nonetheless .

[Tank_Killer]

Is the Receiving client 100base-TX?  If so, do you have flow control enabled?

I highly reccomend disabling flowcontrol on all your 100bTX clients (especially if they are RECEIVING data from a GB client)  This can be done in your router/switch (if you have a layer 2 switch or above) you can also do it software in windoze under deviceman on each client.

perhaps that might help. If not then i would suspect something wrong in your topology, poor cables/slow client PC (virii ect)/poor switch+router.

Also keep in mind READS from the NAS will always be faster than WRITES to the NAS so if were talking 9-12MB/s WRITES.  this is definitly within parameters, i would think you have limited exp with NAS as cheaper NAS devices come nowhere near this performance.  THere is certainly faster devices, but their like 500+ dollars (yeesh)

[fordem]

Also keep in mind READS from the NAS will always be faster than WRITES to the NAS so if were talking 9-12MB/s WRITES.  this is definitly within parameters, i would think you have limited exp with NAS as cheaper NAS devices come nowhere near this performance.  THere is certainly faster devices, but their like 500+ dollars (yeesh)

This is not necessarily true - a read from the NAS is a write to the local drive - and the speed at which the local drive can be written needs to be considered.

I have one particular desktop - 3GHz, dual core P4, 512 MB RAM, gigabit ethernet and the exact same model of 80GB SATA disk that is in the DNS-323 - reading from the DNS-323 is a dismal 5 MB/sec (single 2GB file), wheras writes are almost twice the speed of a read.

[Zardoz66]

8 to 12 MB/s is very normal for this NAS device. however I have see in the upwards of 20 MB/s but it all depends on a lot of factors. it is very true that this device is slower then other NAS devices but we are talking other NAS devices that cost way more then what this unit does. Just to let you know I get about 40 to 50 MB/s from my raid 5 SATA array on my PC server. but the cost of that equipment is way more then the 150ish for this device.

For the most part this device is OK, it has it's quirks, but does the job I need and that is back up data from main storeage.

[jesbo09]

My DNS-323 is connected to a Gig-E switch. I ran a Sandra File System Benchmark from my Core-2 DUO PC with Gig-E NIC to the DNS-323 samba share via mapped drive letter and got the following test results using a 2 GIG Test File and 1 Meg Block Size:

Buffered Read: 30 MB/Sec
Sequential Read: 23 MB/Sec
Random Read: 15 MB/Sec
Buffered Write: 25 MB/Sec
Sequential Write: 18 MB/Sec
Random Write: 14 MB/Sec
Random Access Time: 23 Msec

No other users were accessing the device during the tests.  A "Top" running on the DNS-323 showed 95%+ CPU utilization on the DNS during some of the tests, indicating that the CPU on the DNS-323 is often the limiting factor.  The DNS was configured Raid-1.

[fordem]

Nice work Jesbo.

[jesbo09]

In addition to the tests I posted earlier, here's a log of a few FTP transfers of a 4.6 Gig file.  FTP upload (DNS-323 write) as you can see was much faster than the FTP get. Of particular note... The DNS-323 CPU was 100% busy during the upload, but was only 50% busy during download.

Code: [Select]

Local directory now I:\.
ftp> bin
200 TYPE is now 8-bit binary
ftp> put test.dat
200 PORT command successful
150 Connecting to port 5002
226-File successfully transferred
226 246.707 seconds (measured here), 18.47 Mbytes per second
ftp: 4777378304 bytes sent in 246.67Seconds 19367.33Kbytes/sec.


ftp> get foo.dat
200 PORT command successful
150-Connecting to port 5004
150 4665408.5 kbytes to download
226-File successfully transferred
226 514.467 seconds (measured here), 8.86 Mbytes per second
ftp: 4777378304 bytes received in 514.46Seconds 9286.16Kbytes/sec.
ftp>

[drick]

Now - this is a topic that has been discussed adnauseum - a search of the forum should bring up several threads, including links to file transfer and I believe network speed testers.

fordem, what speed test tools are used here as a "standard"? i did a search of speed test, and got a lot of results but no links.

i'm installing sisoft now, but seem to recall that reading in one of the other posts that someone here had written a utility to test this?

[fordem]

Try searching for NASTester - that is the utility that was written for the task at hand.

Take a look at this thread - look for a post by mig about 8 posts down.

[drick]

thanks, that is what i was looking for.

interesting results, i pulled that down and ran it from the "worst" location on my network which is 3 hops away from my 323.

avg of 3.62MB/sec with a high run of 5.33MB/sec. these numbers don't jive with what i see when i'm running backups, so i'm not sure which to trust.

on the fastest segment however, the system i ran it from hit the 323 so hard, it lost the network share.

no results, program crashed. i'm taking that as a good sign.

[fordem]

thanks, that is what i was looking for.

interesting results, i pulled that down and ran it from the "worst" location on my network which is 3 hops away from my 323.

avg of 3.62MB/sec with a high run of 5.33MB/sec. these numbers don't jive with what i see when i'm running backups, so i'm not sure which to trust.

on the fastest segment however, the system i ran it from hit the 323 so hard, it lost the network share.

no results, program crashed. i'm taking that as a good sign.

Just so you know - traditionally "a hop" would be between one router and the next, which I doubt is the context in which you are using the term.  Do a traceroute and see how many "hops" you get - I'm betting on one.

Now - when using NASTester, try a 2GB file size (assuming you're running a gigabit LAN), and reduce the number of iterations - you may get the impression the app has crashed or hung, because it does not update the screen between iterations - just leave it a little longer.

File size has a significant impact on throughput - 2GB of data as a single file will transfer a heck of a lot quicker than 1000 x 2MB files - for each file read/written the disk drives' heads must move from the data storage area to the allocation table area (see note below) and back, and they cannot write during this move.

One of my servers, when NASTester is used with a 2GB file, can write at approximately 24MByte/sec, yet a backup from the same server delivers approximately 0.5Mbyte/sec if it's done on a folder by folder basis.

Note - before anyone decides to take me to task for the use of the term "allocation table" - every random access data storage system uses some sort of block allocation table, with DOS it was known as the file allocation table, with the ext2 file system used by linux it's referred to as a "bitmap", but it serves the same purpose - it allows the file system to keep track of which blocks have been used and which are available.

One last thing - if you can "hit" the 323 hard enough to lose the network share - it's pointing to a problem with your network, you're getting some sort of an error that is forcing the ip stack to retransmit and when the retransmits reach a critical point the network crashes, which is why the share is lost - the 323's network subsystem is capable of moving data at speeds approaching 400 mbit/sec - significantly faster than it can be written to the disks.

[drick]

sorry, you are correct. in my instance hop=a switch from source to destination.

I just changed the setting to 2GB, and the same thing happened. I'm getting error messages inside the tool BTW, not that the app is hanging.

I'm not clear on what is wrong with my network, or why it would only surface when running this test but perhaps you can educate me further on what i'm doing wrong since you seem to be a but ahead of my learning curve.