Transfer speeds very low after adding two new drives


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My hardware is pretty old so I am aware that bottlenecks are here, but I was getting a transfer rate of about 30MB\s. I added two WD Red 4tb drives that I picked up a couple of days ago. The parity check finished earlier this morning so I started moving more files over, but now I am getting a transfer rate of about 15Mb\s. In addition to the drives I also had to add in this: https://www.amazon.com/gp/product/B07PD9QYRN/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 

This is the second such card I have. I have been using this one: https://www.amazon.com/gp/product/B08CHBM29K/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1 for a little over a week now and didn't have any issues with it. Couldn't get the same one again as it was out of stock, but they looked the same I thought. 

I had cache set to off for this share but if I turn it on my transfer rate goes up to closer to 70MB\s so I don't think it's anything to do with my network. Would having 2 of these cards cause an issue? Is something wrong with my configuration? I checked the serial number on these drives because I read about an CMR vs SMR controversy with these which can slow things down but according to my search my drives should not be affected by that. Is there anything I could do to get back to the 30MB\s I was at at least? I attached my latest diagnostics in case that helps. Thank you.

tower-diagnostics-20210123-2250.zip

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7 hours ago, JorgeB said:

Those controllers are PCI, the whole PCI bus (133MB/s max speed) is shared by all the devices using it, so terrible for performance, you should really use PCIe controllers.

I have no PCIe slots left, or I would. I had to remove my graphics card to install a NIC. Like I said in earlier posts, very old hardware I am trying to put to better use. I have, I think, only one drive on the 2nd PCI controller. So maybe if I remove that drive from the array and just use that drive with unassigned devices performance for that share with the rest of the drives would improve?

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Lets say the above is true and not using the 2nd pci controller will fix my issue. Supposing I have disks 1-5, plus 2 parity. I want to remove disk 5 from that share (and probably the computer and just return the controller card). Whats the best way to do that without messing up parity or losing data? If I go to "Main" and browse disk 5, it doesn't show any files or folders on that drive. I also looked at it with midnight commander in /mnt/disk5 and it also shows nothing there. Can I go into my shares, tell it to exclude disk 5, and then pull it without breaking anything?

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You cannot remove any drives without invalidating parity :( 

 

sounds like your best way forward i

  • Tools->New Config and select the option to keep current assignments.
  • return to the Main tab and remove the drive(s) you np longer want in the array
  • start the array to rebuild parity based on the remaining drives.

Unraid will recognise those data drives that are already in an Unraid compatible format and will leave their data intact.    The risk you take (which I think is unavoidable) is one of drives you are keeping failing before rebuilding parity is complete.    Do you have backups of anything critical (you always should have) as parity is about high availability - not guaranteeing that you will never get data loss.

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18 minutes ago, itimpi said:

You cannot remove any drives without invalidating parity :( 

 

sounds like your best way forward i

  • Tools->New Config and select the option to keep current assignments.
  • return to the Main tab and remove the drive(s) you np longer want in the array
  • start the array to rebuild parity based on the remaining drives.

Unraid will recognise those data drives that are already in an Unraid compatible format and will leave their data intact.    The risk you take (which I think is unavoidable) is one of drives you are keeping failing before rebuilding parity is complete.    Do you have backups of anything critical (you always should have) as parity is about high availability - not guaranteeing that you will never get data loss.

I was afraid of that. Although I was incorrect in an earlier post in this thread. It looks like I do have a PCIe slot available. So I could add a faster controller card and return the PCI controllers in exchange. I have looked at the hardware wiki. I am having a really hard time finding a compatible controller on a budget though. Seems like all the 4-6 port cards are using unsupported chipsets as far as what is avail on amazon. Most are using Marvell which seems to not be recommended. The sale page for this one says it works with linux though. Could I get away with this one? https://www.amazon.com/Rivo-Splitter-Controller-Expression-Profile/dp/B07Z88N9KP/ref=sr_1_52?dchild=1&keywords=pcie+sata&qid=1611523128&sr=8-52

 

I mean, I can't afford to get a high end controller. By the time in the $100 plus range I start to think I may as well just get a cheap new motherboard and hope I can find a reasonably priced low-end ryzen.

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The normal recommendation is to go for any LSI based controller flashed to work in IT (i.e. not RAID) mode and that would support 8 drives (there are also 16nport models but they are more than twice the price of the 8 port ones).  The 8 port models can be got for very reasonable prices on eBay.   It is often better to go fo a used one recycled from a server as new ones from China have sometimes turned out to be fake.

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1 hour ago, John_M said:

Alternatively, if you only want a 2-port SATA controller, ones based on the ASMedia chips (such as the ASM1061 or 1062) are cheap and compatible.

 

Thanks, the one I linked a couple posts up is using an ASM1062, or at least so it says, but after looking at the LSI controllers that seems the better way to go. I just have to watch price since most of them don't seem to have cables with them. That and I don't want to get scammed.

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