Slow speeds using iSCSI LUN

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SmelliotButton
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Slow speeds using iSCSI LUN

Post by SmelliotButton » Fri Mar 19, 2021 5:27 am

Hi,

After looking through the forums I couldn't really see anything similar to my issue - apologies if I missed something!

I have a QNAP TS-469U with four WD 3TB Red drives running in RAID 10. I then have a VMware ESXi 7 running a few Windows Server 2019 virtual machines. Linking the two is a HP 1810-24G switch and CAT5e cables.
The two 1Gbps Ethernet ports on the QNAP are setup with Port Trunking, running IEEE 802.3ad. I have made sure that the HP switch supports 802.3ad. Jumbo Packets have been enabled on the QNAP NAS and the Switch.

As an example, when copying a 13GB .zip file from my local machine (SSD drive) to a shared folder on one of the virtual machines, I get a steady 100MB/s copy speed (although the virtual machine is running on an SSD drive connected directly to the VMware ESXi host). This test was more to rule out any issues with the switch.
When copying the same file to a LUN hosted on the QNAP NAS, the copy firstly starts at around 1.3GB/s but then drops down to around 60MB/s quite quickly and continues at that speed for the remaining copy time.

The fact that copy starts above 1GB/s makes it seem that the NAS is capable of that transfer speed, but something is then slowing it down. I am aware that the logical transfer speed would never be possible, but am I right in thinking that I should be getting a maximum of 250MB/s? Due to two WD Red drives running at 140MB/s each and them running in RAID 0, and then the Port Trunking ports on the switch running at 250MB/s total?

Sorry if this seems like a jumbled wall of text! If there is anything I need to check or clarify to help please let me know.

Thanks in advance!


Edit:
Just to confirm, the QNAP NAS is running the latest firmware of V4.3.4.1463 (2020/10/06). The firmware is also up to date on the HP switch.

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dolbyman
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Re: Slow speeds using iSCSI LUN

Post by dolbyman » Fri Mar 19, 2021 10:52 am

checked a couple of reviews from when that atom unit was new(2013) ..all have it hover under 100MB/s max.(read/write) Trunking would also only improve transfers from multiple systems

SmelliotButton
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Re: Slow speeds using iSCSI LUN

Post by SmelliotButton » Tue Mar 23, 2021 9:09 pm

Hi dolbyman,

Thanks for your response and sorry for the delay in mine!

I've confirmed that I have Port Trunking enabled on the NAS using both Ethernet ports and IEEE 802.3ad. Is there anything else I can check?

Thanks,
Elliot

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