Default Iscsi options

[mikep]

Hello, I've tried to tune iscsi. I've matched the suggested tagets config on this forums with initiators but I had better performance with default config.
Sadly I did not copy it before start changes.
Could you please tell me what are the iscsi target default options?

Regards

[To-M]

MaxRecvDataSegmentLength 8192
MaxBurstLength 262144
MaxXmitDataSegmentLength 8192
FirstBurstLength 65536
DataDigest None
MaxOutstandingR2T 1
InitialR2T Yes
ImmediateData No
HeaderDigest None
Wthreads 8

[mikep]

Thanks Todd!

Regards

[mikep]

Hello again. I really not understand what is going on. I have very unconsistent results here. With default iscsi values are worst than ever.
Also I have non sense hdparm results on tests.log:

From:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:
Timing buffered disk reads: 454 MB in 3.00 seconds = 151.28 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 1070 MB in 3.00 seconds = 356.32 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:
Timing buffered disk reads: 714 MB in 3.00 seconds = 237.77 MB/sec

*-----------------------------------------------------------------------------*
To this one now:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:
Timing buffered disk reads: 444 MB in 3.01 seconds = 147.52 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sda
*-----------------------------------------------------------------------------*


/dev/sda:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:
Timing buffered disk reads: 292 MB in 3.01 seconds = 96.89 MB/sec

*-----------------------------------------------------------------------------*
hdparm -i /dev/sdb
*-----------------------------------------------------------------------------*


/dev/sdb:

*-----------------------------------------------------------------------------*
hdparm -t /dev/sdc
*-----------------------------------------------------------------------------*


/dev/sdc:
Timing buffered disk reads: 470 MB in 3.00 seconds = 156.47 MB/sec

We are usin supermicro based hard, even controller, smc 2108, detected as LSI 9260 (rev 4) by open-e, same chipset. 36 x ST1000NM0001 SAS, two raid 60 and one raid 1 for the system over 82599EB 10 Gbe, cisco nexus sitch.

Have many other hdparm results intermediate. This are highest and lowest.
Any help to understand this results would be appreciated.

Regards

[Pi-L]

hdparm is a synthetic test that does not always give us a realistic results.
Another thing is that speed received from hdparm greatly depends on system load at a time.

[To-M]

Hello again. I really not understand what is going on. I have very unconsistent results here. With default iscsi values are worst than ever.

Regards

Try with the Write Back option for the LUN, also check the tests.log file if there are any NIC issues like dropped packets in the ifconfig -a section of the log.