Question: Reporting->Target - why two graphs?

[cts]

I have shared some zvol via iScsi and I expect to see on the reporting - Target page the "SCSI Target Port (iscsi)" - I am not expecting to see "SCSI target port (tpc)" - what does this represent? Sometimes i see traffic on the (tpc) but not (iscsi) that seems to be concerning.

Any ideas?

 

[joeschmuck]

I believe this is the throughput based on having the TPC option checkmarked when selecting your iSCSI setup. If you turn off that checkmark I'm willing to bet your chart drops to zero. Read the User Manual, it covers the TPC box.

 

[cts]

I did have them checked - and then unchecked them. -- When i stress the system i still still traffic on this graph. Interesting.

 

[joeschmuck]

When I tried to look into this I thought TPC meant transactions per minute completed but the value being reported is in bytes/sec so that doesn't match. Then I thought that it dealt with the TPC option.

Looking at this wiki page it could be just the TCP/IP overhead for iSCSI. Read the Initiator section.