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[robulus]

I have a small office network with a Vista x64 PC that I backup regularly to two D-Link DNS-323 NAS drives (one has FW 1.08, the other is on 1.07). I have a speed issue that I think has started since I upgraded the network to gigabit.

Using AllSync to manage backups (although I can replicate the problem doing large copies over the network in Explorer) copy/comparison speeds start off at about what I expect for a gigabit network with the D-Link drives, around the 20 MBps mark. After an hour or so they have dropped to a trickle, so slow that I haven't managed a complete sync of my 65GB document files in recent memory.

I have a Gigabyte GA EP35C D53R motherboard and I'm using the onboard Realtek 8111B gigabit adapter.

I have got the latest drivers for the adapter from Realtek, and have tweaked the advanced settings, turning off Flow Control, and fixing Speed at gigabit and full duplex.

The interesting thing I have noticed by changing driver settings during a copy, while it is slow, is that after the driver reloads the transfer speed goes straight back up to full bore (no matter what was changed). I am wondering if this indicates an issue with the network adapter (so should I buy a new card) or does it indicate something else?

Network details:
- Vista x64 Workstation, Gigabyte GA EP35C D53R motherboard with onboard Realtek 8111B gigabit adapter.
- 2 x D-Link DNS-323 NAS. Problem occurs with both, one has two 500GB SATA drives formatted in RAID1, the other a single 500GB SATA drive.
- 2 x DIR-825 routers. One is set as the network router with internet connection, the other has DHCP disabled and essentially functions as a switch / wireless extender.
- TENDA TEG-1008 gigabit switch.
- Cat6 cable throughout.

The issue occurs with both DNS-323s, which are connected to the Workstation as follows:
VISTA Workstation -> DIR-825 (Router) -> DIR-825 (Switch) -> DNS-323
VISTA Workstation -> DIR-825 (Router) -> TEG-1008 (Switch) -> DNS-323

I've done a lot of reading and experimenting, so here's the stuff I've tried out:
- Both DNS-323's set to gigabit connection
- Disabled Remote Differential Comparison
- Disabled Offline Files
- Tried to install the Microsoft Vista patch for slow file transfers (error, not for my system)

If anyone can help me solve this I'll be eternally grateful!!!

[gunrunnerjohn]

A dumb question, have you tried file transfers to another system, preferably not Vista?  FWIW, I've noticed some anomalies with Vista here under certain conditions, and I found that disabling auto-tuning for the TCP/IP stack fixed mine.  Here's the tests I did here.

Tests from Win7 64-bit machine to Vista and XP.
----------------------
Win7 to XP      20 mbyte/sec
XP to Win7      38 mbyte/sec

Win7 to Vista   3 mbyte/sec .. Autotuning=normal
Vista to Win7   3 mbyte/sec .. Autotuning=normal

Win7 to Vista   36 mbyte/sec .. Autotuning=disabled
Vista to Win7   40 mbyte/sec .. Autotuning=disabled



Tests from Vista 32-bit to Win7 and XP.
-----------------------
Win7 to Vista   46 mbyte/sec
Vista to Win7   31 mbyte/sec

Vista to XP     20 mbyte/sec
XP to Vista     37 mbyte/sec



Tests from XP to Win7 and Vista.
-----------------------
XP from Vista   3 mbyte/sec .. Autotuning=normal
Vista from XP   3 mbyte/sec .. Autotuning=normal

XP from Vista   35 mbyte/sec .. Autotuning=disabled
Vista from XP   25 mbyte/sec .. Autotuning=disabled

XP from Win7    27 mbyte/sec
Win7 from XP    21 mbyte/sec


Tests from Win7 to D-Link DNS-323 (NAS)
---------------------------------
Win7 to DNS-323     17 mbyte/sec
Win7 from DNS-323   16 mbyte/sec

[robulus]

Hi John, thanks for the reply.

It seems like a dumb question, especially to someone who has a couple of idle servers sitting on the same network, and yet I hadn't tried it, so it was an excellent suggestion!

I have an Ubuntu Linux Server on the same network, so I did some tests with that. The short of it is backups and syncs to the Ubuntu server worked flawlessly and with such blistering speed that I may have to rethink my backup strategy! None the less I like the convenience of the NAS devices, and if they were working consistently at the speed they start off at (file transfers at around the 16MBps mark, just like your tests) they would be fine for the job.

The Ubuntu server was showing file transfer rates averaging around 50MBps, peaking at around 60MBps, which indicates a very healthy network environment indeed.

I'll try disabling auto-tuning on Vista, and see if this changes anything.

Here are the summaries of my backups, using the same data for each comparison.

Ubuntu Server: 12GB First backup


26/02/2010 10:23:56  ==================================================
26/02/2010 10:23:56  Copy operation started.
26/02/2010 10:23:56  ==================================================
26/02/2010 10:30:19  PROFILE STATISTICS:
26/02/2010 10:30:19  Elapsed time: 0:06:23
26/02/2010 10:30:19  Files: 7484 created, 25 deleted
26/02/2010 10:30:19  Folder: 437 created, 34 deleted
26/02/2010 10:30:19  Data volumes copied to the destination folders: 13,234,114.75 KB
26/02/2010 10:30:19  --------------------------------------------------
26/02/2010 10:30:19  Copy operation completed.
26/02/2010 10:30:19  --------------------------------------------------


Ubuntu Server: 12GB Sync


26/02/2010 10:31:29  ==================================================
26/02/2010 10:31:29  Copy operation started.
26/02/2010 10:31:29  ==================================================
26/02/2010 10:31:39  PROFILE STATISTICS:
26/02/2010 10:31:39  Elapsed time: 0:00:10
26/02/2010 10:31:39  No changes have been made.
26/02/2010 10:31:39  --------------------------------------------------
26/02/2010 10:31:39  Copy operation completed.
26/02/2010 10:31:39  --------------------------------------------------


DNS-323: 12GB First backup


26/02/2010 10:34:27  ==================================================
26/02/2010 10:34:27  Copy operation started.
26/02/2010 10:34:27  ==================================================
26/02/2010 10:50:59  PROFILE STATISTICS:
26/02/2010 10:50:59  Elapsed time: 0:16:32
26/02/2010 10:50:59  Files: 7484 created
26/02/2010 10:50:59  Folder: 437 created
26/02/2010 10:50:59  Data volumes copied to the destination folders: 13,234,114.75 KB
26/02/2010 10:50:59  --------------------------------------------------
26/02/2010 10:50:59  Copy operation completed.
26/02/2010 10:51:00  --------------------------------------------------


DNS-323: 12GB sync

26/02/2010 10:51:17  ==================================================
26/02/2010 10:51:17  Copy operation started.
26/02/2010 10:51:17  ==================================================
26/02/2010 10:55:06  PROFILE STATISTICS:
26/02/2010 10:55:06  Elapsed time: 0:03:49
26/02/2010 10:55:06  Files: 799 copied, 5 created, 1 deleted
26/02/2010 10:55:06  Folder: 1 created, 1 deleted
26/02/2010 10:55:06  Data volumes copied to the destination folders: 2,775,214.84 KB
26/02/2010 10:55:06  --------------------------------------------------
26/02/2010 10:55:06  Copy operation completed.
26/02/2010 10:55:06  --------------------------------------------------


Ubuntu Server: 60GB First backup


26/02/2010 11:02:26  ==================================================
26/02/2010 11:02:26  Copy operation started.
26/02/2010 11:02:26  ==================================================
26/02/2010 12:30:54  PROFILE STATISTICS:
26/02/2010 12:30:54  Elapsed time: 1:28:28
26/02/2010 12:30:54  Files: 467946 created, 75 deleted
26/02/2010 12:30:54  Folder: 93371 created, 55 deleted
26/02/2010 12:30:54  Data volumes copied to the destination folders: 63,914,304.86 KB
26/02/2010 12:30:54  --------------------------------------------------
26/02/2010 12:30:54  Copy operation completed.
26/02/2010 12:30:54  --------------------------------------------------


Ubuntu Server: 60GB sync


26/02/2010 13:34:42  ==================================================
26/02/2010 13:34:42  Copy operation started.
26/02/2010 13:34:42  ==================================================
26/02/2010 13:55:16  PROFILE STATISTICS:
26/02/2010 13:55:16  Elapsed time: 0:20:34
26/02/2010 13:55:16  No changes have been made.
26/02/2010 13:55:16  --------------------------------------------------
26/02/2010 13:55:16  Copy operation completed.
26/02/2010 13:55:17  --------------------------------------------------

DNS-323: 60GB backup / sync does not complete after 12 hours, hangs.

[Clayton]

disabling auto-tuning for the TCP/IP stack ?

Sounds interesting, is that for computer to computer transfers only and eliminating the DNS-232?

[robulus]

Computer to computer transfers are fine (unbelievably good, in fact), so I would only be interested in doing it if it will fix the issue with the DNS-323.

[robulus]

Managed to disable autotuning, after disabling heuristics. This hasn't affected the slow-down issue with the DNS-323 though, it is still the same.

[fordem]

Using AllSync to manage backups (although I can replicate the problem doing large copies over the network in Explorer) copy/comparison speeds start off at about what I expect for a gigabit network with the D-Link drives, around the 20 MBps mark. After an hour or so they have dropped to a trickle, so slow that I haven't managed a complete sync of my 65GB document files in recent memory.

It's been my experience (with Microsoft's SyncToy) that syncing large numbers of small files is dismally slow - with the compare before the actual data transfer taking what seems to be forever.

I've also noted that transferring large numbers of small files is significantly slower than if I were to transfer the same volume of data as a single file, or even a small number of larger files - you might want to reconsider how you do the backup, and use a utility that compresses the data and then writes it to the storage in blocks rather than as individual files.

[gunrunnerjohn]

fordem is 100% correct, small files really slow this NAS down.  Any benchmarks I do are for large files, I assume that as the files get smaller, the times get longer for the same amount of data transfer.

[robulus]

No, there is definitely some network issue here. It slows to the point that I abandon the backup after 12 hours because it's been stuck on 27%. I installed the backup software and the complete 60GB of data on an XP server with a Marvell Yukon NIC, and it ran the full backup in one hour twenty minutes to the DNS-323. I'm going to try swapping the network card.

[gunrunnerjohn]

I would say the top suspect would be the network drivers here.  Doesn't sound like the NIC, but anything's possible.

[robulus]

Thanks GRJ, your hunch looks right. I installed an Intel PRO/1000 GT card, and still get exactly the same issue.

I tried disabling IPv6 and Teredo, I ran TCPOptimizer, and I've tested a pretty exhaustive list of Vista network changes from the searches, including everything listed here: http://www.chicagotech.net/vista/vistaslow.htm and disabling auto-tuning.

All to no avail.

I haven't yet tried connecting the DNS-323 directly to the Vista PC, so I'll try that next just to rule out router issues. I'm rapidly approaching more of a "throw the whole f#@&ing network out the f#@&ing window" style of problem solving though.

[gunrunnerjohn]

Sneaker net, the modern way to network. :D

[courtec]

Try disabling jumbo frames on the dns-323.

I had a funny speed problem after I up graded from 1.03 to 1.08. Copies would be fast for a few seconds and then go to a crawl 3 mb/sec.

After a lot of hair pulling it turns out I enabled jumbo frame size on the dns-323 in conjuntion with the upgrade. Once I disabled this my speed shot up to 18-16 mb/sec reads.

[robulus]

Thanks, but I tried enabling / disabling jumbo frames, that wasn't it. I can confirm that enabling jumbo frames on the DNS-323 by itself does decrease performance.

Unfortunately, I couldn't get past the excellent performance I was getting from the Linux server, and I've sold my two DNS-323s and replaced them with fileservers. My backup is complete in an hour or so now.

[gunrunnerjohn]

That's the reason I have a Synology DS209 now as my primary NAS.  It is 3-4 times as fast as the DNS-323.