TerraMaster Forum

I have a question regarding transfer speeds using iSCSI.

For the first gigabyte or so of data, i can transfer to my F5-221 in Raid 5 iSCSI target at about 175+mbs, but then it drops off drastically to only <10mbs and continues at that speed for the remaining duration of the transfer, regardless of size.

This means i can transfer a 1gb file nearly instantly, but if i transfer a number of 1gb files, it can take hours.

Does anyone know what is causing this iSCSI speed drop-off? I suspect it's to do with a write buffer filling up somewhere?

Can you tell us what type of hard disk you are using? An inappropriate or poor disk may have a cache problem which can cause such a problem.

A lot small size files can also cause speed drop during transfer.

TMzethar wrote: ↑23 Dec 2020, 22:37 Can you tell us what type of hard disk you are using? An inappropriate or poor disk may have a cache problem which can cause such a problem.

Using x5 WD120EMAZ 5400rpm, 256mb cache drives in a raid 5 array.

TMroy wrote: ↑23 Dec 2020, 22:53 A lot small size files can also cause speed drop during transfer.

This is happening for all file sizes.

So many problems from WD white lable drives, same story, read this viewtopic.php?f=25&t=1169&start=20 Did you shuck these drives from WD USB Elements? This is not a recommanded drive.