D-Link Forums
The Graveyard - Products No Longer Supported => D-Link Storage => DNS-321 => Topic started by: sully on April 04, 2010, 10:52:39 AM
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The problem is that backups run at about 300 kB/s (~2.5 Mbps)!
OK, this post probably belongs on a MS forum because I am pretty sure my problem is windows and not DNS-321.
I am running windows 7 pro x64.
I am connected by wire through a cheesy router that came from at&t.
Windows Backup runs slow.
Easeus Todo Backup runs at the same slow speed.
I can transfer large files via windows explorer at full 100 Mb/s speed, so I know I have good connection from PC to NAS.
I have a Vista Home Premium x86 laptop that gets in the neighborhood of 30 Mbps over the wireless using both Windows Backup and 3rd party.
I'm not sure what the problem is, but I am hoping somebody on this forum has seen it before.
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I would guess it's how the files are being written.
I suspect it's doing a lot of small files and/or random access within the file as it backs up.
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The problem could certainly be many small files, which each are transmitted separately and therefore slow down because of latency issues and small-sized packets. If so, here are a couple options:
1. Zip up the files you want to backup, then transfer the single large zip file.
2. Windows 7 supports multi-threaded Robocopy (http://technet.microsoft.com/en-us/magazine/dd542631.aspx). This might help because it will try to sync multiple small files simultaneously.
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You should not have such a slow speed.
Try this simple test on your computer...
Copy a large file (25MB or larger, I used a 1GB .vob file, you are looking for something that takes 15 seconds or so to transfer, no small files) from your computer to your NAS. I get ~18MB/sec rate. What does Windoze report for a transfer rate?
Here are the factory you are looking at which impact transfer rate:
1. Format of your NAS drives (EXT2 or EXT3)
2. File fragmentation on your computer.
3. Small files.
4. Jumbo Frames/MTU Setting.
I'll run through this QUICKLY since I've posted this before here but...
1. EXT2 is faster that EXT3 however not as reliable for data safety. On my system I get 18MB/sec using EXT2 format (bursts are faster of course), and 13 MB/sec with EXT3.
2. File Fragmentation could be an issue during the backup.
3. Small files is not normally an issue during backup but like file fragmentation it could be.
4. If you haven't set your NAS to enable Jumbo Frames and set the MTU to 4000, I highly recommend it. This increases the amount of data transmitted before the next handshake/error corretion check.
Last thing, don't use your backup program as an indicator of data throughput for your NAS. There are things going on which can easily slow things down. And my favorite backup program is Acronis. It costs $50.00 (free download and trial period) and you can restore everything from a single bootable CD, no need to install Windoze first.
Let me know if this helps...
-Joe
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GRJ/Joe/Ben,
Thanks for all the suggestions. Sorry for my slow response to your posts. Sorry for not inline quoting your suggestions - this is going to be a long post.
The problem is solved! First, I give the answer, and then, I respond to your comments. I found good advice on this thread: http://forums.whirlpool.net.au/forum-replies-archive.cfm/1400059.html (http://forums.whirlpool.net.au/forum-replies-archive.cfm/1400059.html). The key is in the adapter settings. Go to Network Connections. Right click on the adapter. Select "Properties." Click "Configure." Select the "Advanced" tab at the top. Disable "Interrupt Moderation" and all of the Offloads - 7 different selections to choose from. Then, voila, 60-70Mbps! Considering the router is a 100Mbps at&t provided box, this is probably the best I can expect.
Things I learned after the first post: the problem wasn't just uploading to the NAS; I had the same speed issue uploading from the win7 box to a laptop on the same network. Downloads were always fast. The laptop on the other hand was always faster. The speed limitation didn't seem to be physical. I could launch a bunch of transfers simultaneously, and each transfer would be painfully slow, but the total transfer rate would be higher than the 250kB/sec limit I reported - not in 250kB increments - but faster than 250kB. Finally, I booted to XP, and the upload rate was high, so I could exclude the mobo as the problem. That focused my hunting on Win 7. Many people in various threads suggested rolling back the drivers, but this did nothing for me. I rolled back the NIC driver, the PCI bus drivers, etc. Nothing helped. In the end, it was all settings.
GRJ:
- The file was huge - eventually 30GB. Could have been opened and the random accessed. I don't know.
Ben:
- As stated to GRJ, it was a large file. I did all my testing with large files, too. The smallest was 30MB. When I wanted to have enough time to do all the diagnostics I could imagine, I used the 30GB file. The transfer rate for uploads always bounced between 1-3Mbps with an average of about 2.5. Downloads were always fast.
Joe:
- Totally agree. I definitely should have had faster speed. I appreciate that you sided with me on this one. ;) With only 100Mbps capability, it will be very hard for me to exceed 12MB/sec.
- I was seeing about 250kB/sec! As per response to Ben, large files.
- I don't know about the format. Sorry for being a nu-b. I don't see that drive format is on the web interface, and I am just getting my arms around ffp, so still figuring out how to answer the question. It has been a long time since I have used unix/linux.
- Fragmentation should be good as it is a brand new build of Win7 and app install. 40GB on 200GB drive. Fixed size swap file. 1% fragmentation reported by MS supplied utility.
- Thanks for the suggestion. Large files.
- Checked it. Jumbo frames off in settings on both NAS and the Win7 box. I don't have a GB switch in the router, so I think jumbo does nothing for me?
Thank you very much for taking the time to repeat yourself again and for helping me. I also appreciate your other suggestions. I was never really down on the DNS box. It's inexpensive and generally far exceeds expectations. I was pretty sure the problem was with the win7 and not the NAS. Lurking on this board, I was impressed with the quality and care of advice and suggestions given, so I thought I would give all-y'all a try first. I wasn't let down.
Thanks all for the help!
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Perhaps a REALLY large file will also slow the box, the biggest I've written are about 12gigs, they're True Image backups of systems here. You should get a lot better performance than 250kbytes/sec, that's for sure.