Windows 10: File transfers stop every 5 seconds

When I copy a file from my PC (typically the source is a 970 Pro 1TB), to an internal disk on my file server over my 10Gbit network it starts at 1.1GB/s then drops to zero, where it stays for 20-30 seconds, then goes back up to 1.10GB/s for 2-3 seconds, then drops to 0 again. This repeats until the file is copied.

If I copy the file to a drive attached to the server via USB I get a solid 220 - 240MB/s

I upgraded to Windows Server 2019 (1809), from Windows Server 2012 R2. There was a reason, apart from 2012 R2 mainstream support ending in 2018, something wasn't compatible... I just don't recall what that was.

On 2012 R2 copies would vary between 800 - 1100MB/s but would never stop

I also installed a new 12TB drive around the same time.

So, without going back to Server 2012 R2 to prove it, I don;t what else to do.

The drives are either ST10000VN0022 (x6), or ST12000VN0008 (x5). Network is all 10Gbit.

My gut tells me it sounds like a caching issue, but caching is enabled on all drives.

Before I go spend a day re-installing 2012 R2 to prove if that's the cause, any one have any other ideas what might cause this behavior across all internal disks?

EDIT: I've run chkdsk and defrag over all drives.

:)

 

File transfers stop every 5 seconds

I'm pretty sure I'm not suffering from hallucinations. Once I've gone back to 2012 R2 I'll take some pics. But for now, here's some of the server copy and to/from USB. The server copy on 2012 R2 was not this bad - sure there was some fluctuations in speed, but not grinding to a complete halt.

I know what's happening - it's filling the cache and waiting for the write to finish then starting again. But this was not an issue on 2012 R2. Maybe it's the specific drive failing? I'll run Seagate's Seatool's across the drives and see what that says.

 

File transfers stop every 5 seconds

Thanks for your reply.

When I say MB/s I mean MEGABYTES per second. Not bits.

Yes, I am sure my network is 10G. The NICs are 10G. The cables are Cat6, the switches are 10G Netgear MS510-TX. Network properties shows the NICs at both ends running at 10G. RSC has been disabled at both ends, which according to Netgear is supposed to stop erractive transfer speeds, and Fast connect is also enabled on the switch ports.

But bear in mind, before upgrading Windows Server and upgrading a drive, this all worked fine.

On a gigabit network, best transfer speeds are 113MB/s regardless of the source or target device, and regardless of the target being internal or external.

The External USB drive is a USB 3.2/3.1 Gen 2 over USB Type-C that runs at Max theoretical of 20Gb/s (bits). That is why I get 240MB/s (bytes) sustained transfer speed. That's twice the gigabit link performance, and since low usage stuff and backups are on the external drive, I'm fine with only doubling my transfer speed there. It's the internal drive speeds that no longer performing

When copying to the internal drives on Windows 2012 R2 I was getting speeds of 800MB/s - 1100MB/s (bytes). I upgraded to Windows Server 2019, and also upgraded one drive and the speeds are now 1100MB/s (bytes) for 3 seconds, 0B/s (bytes) for 20 - 30 seconds, then 1100MB/s (bytes) for another 3 seconds etc.

Even with write caching enabled on the drives this behavior is the same.

The theoretical max sustained write speed on the NAS drives is 210MB/s (bytes) with a 256MB cache.
https://www.seagate.com/www-content/...04GB-en_AU.pdf

I timed a transfer of a 50GB file. Averaging the speed over the total time, I managed to get an average transfer speed of 40MB/s, that's one third of the sustained speed of a gigabit link.

I don't recall the reasons why I felt compelled to upgrade to Server 2019. I guess I'll be reminded as soon as I go back to 2012 R2, which it looks like I'm going to have to do. WSUS is broken on 2019 anyway, so I'll possibly fix two issues by reverting.

 

Cable to transfer files

OMG. I have never met anyone who actually bought one of those file transfer things.



Firewire will do the same as USB, but faster, so will a cheap crossover cable. I can wlak you through the steps of moving data so you will not miss a beat.




Anything more than $10 to buy a cable is too much.