Network Drive attached as SCSI Dropping the W/R speed on bigger files

Question

I'm having Network disk attached a SCSI disk

When copying smaller files like 700MB or even 1 GB, speed is high , from 90MB/s to 120 MB, so I'm capable to benefit from 1Gbit network. But if files is around 4 GB, the speed is dropping in 10 Seconds and goes to 15-8 MB/s , I understand its getting capped, So I'm wondering, shall I look in to the router, some sort of burst feature, or windows has some sort of capping too?

Hard drive in configured using Lenovo NAS Dirive, there is no such think, its some sort of build in nic — , Feb 23 '17 at 19:51
I mean the nic on your windows server :) not on the NAS, as windows reserver for itselft a large part of the bandwidth — yagmoth555, Feb 23 '17 at 20:12

score 4 · Answer 1 · answered Feb 23 '17 at 19:57

4

You have caches at both sides so while writes are write-buffered you get wire speed, eventually performance goes down.

https://blogs.technet.microsoft.com/josebda/2014/08/18/using-file-copy-to-measure-storage-performance-why-its-not-a-good-idea-and-what-you-should-do-instead/

https://sqlperformance.com/2015/08/io-subsystem/diskspd-test-storage

Make sure you disable cache when testing!

Parameter Description

-h Disable software caching at the operating system level and hardware write caching

answered Feb 23 '17 at 19:57

BaronSamedi1958

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I'm not really up tot the testing, I'm simply having a trouble when moving large files, let say full 4 Gb cantos bistro's if needed or similar, ?I'll try to play with catches, and will report if that helps.. – Feb 24 '17 at 20:40

Network Drive attached as SCSI Dropping the W/R speed on bigger files

1 Answers1