Hi,

 

I have serious slowdown issues with Unraid when copying files to the array.

When I copy big files over SMB the file transfer will slow down and sometimes even stop for some seconds.

 

nas-diagnostics-20200126-1734.zip

 

 

Edited January 26, 20206 yr by RedReddington

Have you tried turbo write?

3 hours ago, johnnie.black said:

Have you tried turbo write?

Not yet, but i don't want all my drives up all the time. So that wouldn't really help.

@RedReddington Is this when copying to array with cache drives or straight to disks?

3 hours ago, allanp81 said:

@RedReddington Is this when copying to array with cache drives or straight to disks?

Straight to a disk via a user share.

I think I have some I/O issues.

When starting a copy, I see values from 15-20% after a few seconds.

 

Is is possible that I have to many "streams" open from Unraid to my PC?

I can test it very easy when I mount an ISO on my PC from the array and then transfer files back via MKVToolNix to the array.

Edited January 27, 20206 yr by RedReddington

Hi there, 

 

Some more information will be required to help figure this out.  I don't see any reference to "expected results" and "attained results."  How fast are transfers going?  Got any screenshots or videos to show the behavior you are seeing?  Are you copying data to a disk that is also receiving other reads or writes simultaneously?  Please supply some more information so we can help you.

1 hour ago, jonp said:

Hi there, 

 

Some more information will be required to help figure this out.  I don't see any reference to "expected results" and "attained results."  How fast are transfers going?  Got any screenshots or videos to show the behavior you are seeing?  Are you copying data to a disk that is also receiving other reads or writes simultaneously?  Please supply some more information so we can help you.

Transfers are about 70-100 MB/s until it completely goes down to 0 after a while.

Also the file explorer in windows is freezing at the same time (tested from different windows pcs and one macbook).

This happens when I transfer files from the pc to unraid.

I also tested it with an ISO mounted from the array to the windows pc, where I do some MKVToolnix "backup" stuff back to the array (not the same disk where the iso is stored) - > Then it sometimes aborts the job and unmounts the iso.

 

At the moment I am testing a file transfer with 4TB of data from a disk attached via Unassigned Devices to a disk in the array (no cache) in Krusader.

There are several CPU_IOWAIT errors.

 

Edited January 27, 20206 yr by RedReddington

When it goes down to 0, does it stay there until you cancel the transfer?  How long does it stay at 70 vs. dropping?  Maybe you could send us a quick screen record of you transferring something from Windows to a share on Unraid, showing the transfer as it goes.

No, most of the times it will go up again for some seconds.

I can make a video later in the evening to show what exactly is going on.

 

What speeds should be expected from 5400rpm spinners with 1 parity drive?

DiskSpeed Container reports results of 175MB/s+ per drive, that is what making me crazy.

19 minutes ago, RedReddington said:

No, most of the times it will go up again for some seconds.

I can make a video later in the evening to show what exactly is going on.

 

What speeds should be expected from 5400rpm spinners with 1 parity drive?

DiskSpeed Container reports results of 175MB/s+ per drive, that is what making me crazy.

You will get nothing like the raw disk speeds when writing to the parity protected array.    By default speeds of 30-40MBps seem typical.  You might find this description of the Unraid write modes of interest to explain why.

11 hours ago, itimpi said:

You will get nothing like the raw disk speeds when writing to the parity protected array.    By default speeds of 30-40MBps seem typical.  You might find this description of the Unraid write modes of interest to explain why.

Bingo!  That's part of the reason I wanted to see how the transfer looks.  Check out the link Itimpi sent for how things work in Unraid.  If you want faster speeds, you'll need to turn on turbo write (reconstruct write under the disk settings page) and that should improve things a bit.

 

11 hours ago, RedReddington said:

DiskSpeed Container reports results of 175MB/s+ per drive, that is what making me crazy.

This speed is literally unattainable over a 1gbps network.  Your network becomes the bottleneck as 1gbps translates to 125mb/s which when you add a little overhead is closer to 100mb/s.  That's your BEST case scenario and again, the only way you'll get there is with either A) a cache device intercepting those writes or B) turning on reconstruct write mode in the disk settings.

Yes I absolutely understand, that I can‘t expect those speeds.

But I expect speeds about 50-60 MB/s without dropping the connection here and there.

 

I have 2 Mellanox Connect X3 with a 1 to 1 connection to my pc, so gigabit isn‘t the bottleneck. iPerf resulted in a steady 950 MB/s transfer.

 

But it doesn‘t matter if I copy to my pc with 10 gig or to another notebook over the gigabit nic. The behaviour is exactly the same.

Unfortunately I couldn‘t find the time for a video today, but I can manage this tomorrow.

But when I copied the files from the unassigned disk to the array, transfer speeds were about 40-70 MB/s for the whole time, so it‘s a combination of smb and writing to the array that is bottlenecking.

 

Is it a problem to have an iso mounted on the pc and then use the content from that iso to create mkv files to another disk in the array?

 

From my understanding the disk where the iso is stored is only involved in reading and for the mkv files the parity disk and the other disk do both read and write. I saw some forum posts with „fsync“ streams issues in Unraid, is this sorted out?

So I could recreate the problem by simply copying an iso to they array without a cache drive involved.

It doesn't matter what share or drive is involved, it is the same behaviour for all of them.

 

At 40s it will start to go down and stops completely and in the end you can see, that the explorer also froze.

https://gofile.io/?c=MoxnrJ

Password is: unraidsmb

 

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Edited January 30, 20206 yr by RedReddington