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Add 2nd HD, transfer rate slows down RRS feed

  • Question

  • I just unboxed my HP 470 and the install went without incident.  I was anxious to see what the transfer times would be like. With just the one drive installed, I copied 700MB of data from a local drive to a shared drive on the WHS. Vista reported peak transfer rates of up to 10MB per second.  I installed a second 500GB (WD5000AAKS) drive and did another copy from lthe same ocal to the shared folder, and the transfer rates fell to a max of 3MB per second.  Is this typical?  If I add more drives, will it get slower?

     

    Thanks!

     

    Dick

    Sunday, February 3, 2008 3:19 AM

Answers

  •  DickDay wrote:

    I did confirm that whether  or not you have an AV running impacts transfer the rates.  With Eset's Nod32 running, I averaged about 2.5MB/sec copying down from the server to the local PC.  With it shut off, it was averaging just shy of 4MB/sec.

     

    Interesting, thanks for that. Another thing to add to the list Smile Was that AV running on your client or the server?

    Monday, February 4, 2008 3:30 AM
    Moderator
  • Usually there is an option to turn off active scanning of network drives.  You may want to do that or exclude the path possibly.  I know that AV can definately knock the wind out of fast file transfers.

    I have 5 drives in my system that are a combo of SATA II and SATA I drives.  I can get anywhere from 10Mb to 2Mb for file transfers, and there is really no rhyme or reason to the span.

    Assumptions made by most virus software:

    If PC based: Don't need to scan network drives as the files were originally scanned on the PC and then copied to network.
    If server based: Don't need to scan network shares as those files should be scanned by PC's before being copied to network.

    So ideally, if you have AV all around, you should not be scanning the network drives or the network shares.
    Tuesday, February 5, 2008 7:30 PM

All replies

  • Once you go beyond a single hard drive, Drive Extender kicks in. DE moves data off the landing zone to the second disk during your copy, which will slow the overall transfer down.

     

    Have a read through the DE whitepaper: http://download.microsoft.com/download/2/F/C/2FC09C20-587F-4F16-AA33-C6C4C75FB3DD/Windows_Home_Server_Drive_Extender.pdf

     

    Sunday, February 3, 2008 9:07 AM
    Moderator
  • Yep this is typical - had the same sort of results for awhile now

    I have 11 disks in my box and small file transfers were especially very poor although initial burst rate could be quite high for 20 seconds or so

    have seen it go below 1meg/sec

    couple of days ago upgraded my vista to RC1 (pre release service pack) and now have much better transfers - if you are confident you know what you are doing it may be worth investigating

    with RC1 loaded now back in the sustained 10+meg/sec range - much snappier overall - wiyhout changing anything in WHS

    but DE still kicks in to slow things down after a minute or two and you are likely to also see pauses periodically as well

    Basically i think its the sys disk that ultimately limits things as you are copying to the "D" even though you think its a share and DE is reading off the same drive to move the data off onto another drive the new added drive in your case so the drive is getting hit twice which will always slow things down

    so currently i think (from my experience) you are seeing a bit of a problem with vista and a bit with WHS

    when you had one drive i would have expected to see higher transfer rates with a single drive - but again could be the vista factor

    you do not say if you are using gigabit networking or not as 100mbps  would also limit what you could transfer

    Sunday, February 3, 2008 11:50 AM
  • I'm using a Linksys gigabit switch and the Vista box also has a gigabit nic.  I keep reading where others are seeing 20+ MB/sec transfer rates.  I wonder if they are all using XP on the PC?

     

    You mentioned that you installed the Vista RC1. I believe I read that the download/update process could take 'several days'?  Can that be correct?

     

     

    Thanks for all of the replies.

     

     

    Sunday, February 3, 2008 3:03 PM
  • From what we can tell, transfer rate is very system dependant. Some people (like me) don't notice a big drop in throughput, while others see transfer rates drop through the floor when DE is doing its thing.

     

    As Spider says above, the speed of the primary disk on the server can seriously impact transfer rates. Other things that can impact rates as well are disk controller speed, PCI bus speed, CPU speed and RAM (I'd guess in that order). Network speed is usually the last thing to cause problems.

    Sunday, February 3, 2008 6:20 PM
    Moderator
  • Thanks Sam.

     

    The transfer rate is not necessarily  awful, but it does seem really slow compared to what I see others getting.

     

    So, I now have 2 drive in the HP 470. If I add 2 more, will it further decrease the speed?  Will adding 2 more drives increase the safety factor?

     

    Thanks,

     

    Dick

     

    Sunday, February 3, 2008 7:20 PM
  • Transfer rate is definitely something some people are complaining about. I don't believe we've nailed down the bottlenecks as a community, so it's difficult to tell why someone is getting great transfer rates while others are not.

     

    In my experience, adding other drives after the second doesn't decrease the speed any further. Drive Extender is either doing its thing (if you have multiple drives) or not (if you have a single drive).

     

    Adding more disks means you have more space for Duplication. So if you're currently so constrained on space you can't turn on Duplication for your data, adding more disks could increase the safety factory. If you've already got Duplication turned on for all your data, adding more disks won't increase the safety factor further.

    Sunday, February 3, 2008 8:53 PM
    Moderator
  • I did confirm that whether  or not you have an AV running impacts transfer the rates.  With Eset's Nod32 running, I averaged about 2.5MB/sec copying down from the server to the local PC.  With it shut off, it was averaging just shy of 4MB/sec.

     

    And, again, the file transfer rates are not critical for me, but I believe they are a good indicator of what I can expect using the server as a work drive, rather than just for storage.  I program in Microsoft Visual Foxpro.  Running Fox on my local Vista box, and with Duplication enabled for the shared folder that stores the Foxpro project, I really dont' see a latency problem while writing, compiling or testing the projects sitting on the server.  That is my main goal, and the HP seems to be handling that quite well.

     

    I tried the same thing with a LaCie nas drive and the latency was so bad, I had to stop using it.  The LaCie came with 4 empty bays, an ethernet share option and no web interface for remote access. It cost me $599. By comparison, the HP comes with a 500GB drive and remote access built-in (plus the other goodies that I may eventually get to use) for the same money, PLUS it's infinitely faster.

     

    So far, I am really impressed with the HP!  Again, thanks for the help.

     

    Dick

    Monday, February 4, 2008 12:20 AM
  • Oops... correction. That was not a LaCie, it was a Drobo with DroboShare.  Sorry Smile

     

    Monday, February 4, 2008 12:25 AM
  •  DickDay wrote:

    I did confirm that whether  or not you have an AV running impacts transfer the rates.  With Eset's Nod32 running, I averaged about 2.5MB/sec copying down from the server to the local PC.  With it shut off, it was averaging just shy of 4MB/sec.

     

    Interesting, thanks for that. Another thing to add to the list Smile Was that AV running on your client or the server?

    Monday, February 4, 2008 3:30 AM
    Moderator
  • AV was running on the Vista client. The variance was pretty consistent, so at least in my case, there is a way to speed up the transfer rate if needed.

     

     

     

    Monday, February 4, 2008 12:42 PM
  • Usually there is an option to turn off active scanning of network drives.  You may want to do that or exclude the path possibly.  I know that AV can definately knock the wind out of fast file transfers.

    I have 5 drives in my system that are a combo of SATA II and SATA I drives.  I can get anywhere from 10Mb to 2Mb for file transfers, and there is really no rhyme or reason to the span.

    Assumptions made by most virus software:

    If PC based: Don't need to scan network drives as the files were originally scanned on the PC and then copied to network.
    If server based: Don't need to scan network shares as those files should be scanned by PC's before being copied to network.

    So ideally, if you have AV all around, you should not be scanning the network drives or the network shares.
    Tuesday, February 5, 2008 7:30 PM