[OpenIndiana-discuss] Slow write speeds on HGST HUH728080AL5200 via COMSTAR target

[Stephan Budach]

Hi eveyone, 


I have setup three Supermicro storage servers, which are running HGST HUH728080AL5200. I wanted to export each drive as a raw LUN over iSCSI. A fter having installed the latest OI hipster and recovering the primary label from the backups on each disk (which were all bad/corrup, for whatever reason), I went forth and used fdisk to partition the drives to one big partition, on which I created a LUN, which I then exprted over iSCSI. 


The issue I am now facing is, that the read speeds are very good, but writing is really slow. The drives are HGST HUH728080AL5200 and HGST states the following about them: 




Interface: SAS 12Gb/s 
Capacity: (GB) 8TB 

Sector Size (Variable, Bytes/sector): 4Kn: 4096, 4112, 4160, 4224 


Could it be that the fact that the COMSTAR LUN only advertises 512 byte sectors leads to this issue and if yes, can I do something about that? 


Thanks, 
Stephan