Hello,
I'm testing iSCSI under Solaris, and I can't manage to change the "Max Receive Data Segment Length".
Target : Solaris 11.3, Sun iSCSI COMSTAR port provider
Initiator : Solaris 11.3
As the link between the 2 servers has a quite high latency (around 10ms), I would have liked iSCSI to use big data blocks, at least 2MB, around 12MB would be perfect.
So here is what I did :
root@initiator:~# iscsiadm modify target-param -p maxrecvdataseglen=12582912 iqn.2013-03.com.test
root@initiator:~# iscsiadm modify target-param -p firstburstlength=12582912 iqn.2013-03.com.test
root@initiator:~# iscsiadm modify target-param -p maxburstlength=12582912 iqn.2013-03.com.test
However parameters are not correctly applied :
root@initiator:~# iscsiadm list target -v
Target: iqn.2013-03.com.test
Alias: -
TPGT: 1
ISID: 4000002a0000
Connections: 1
CID: 3
IP address (Local): 192.168.0.3:59093
IP address (Peer): 192.168.0.4:3260
Transport Type: socket
Discovery Method: SendTargets
Login Parameters (Negotiated):
Data Sequence In Order: yes
Data PDU In Order: yes
Default Time To Retain: 20
Default Time To Wait: 2
Error Recovery Level: 0
First Burst Length: 65536
Immediate Data: yes
Initial Ready To Transfer (R2T): yes
Max Burst Length: 1048576
Max Outstanding R2T: 1
Max Receive Data Segment Length: 32768
Max Connections: 32
Header Digest: NONE
Data Digest: NONE
I then found than increasing the number of sessions helped :
root@initiator:~# iscsiadm modify target-param -m 2 iqn.2013-03.com.test
But not totally :
root@initiator:~# iscsiadm list target -v
Target: iqn.2013-03.com.test
Alias: -
TPGT: 1
ISID: 4000002a0000
Connections: 2
CID: 29
IP address (Local): 192.168.0.3:34470
IP address (Peer): 192.168.0.4:3260
Transport Type: socket
CID: 30
IP address (Local): 192.168.0.3:44709
IP address (Peer): 192.168.0.4:3260
Transport Type: socket
Discovery Method: SendTargets
Login Parameters (Negotiated):
Data Sequence In Order: yes
Data PDU In Order: yes
Default Time To Retain: 20
Default Time To Wait: 2
Error Recovery Level: 0
First Burst Length: 12582912
Immediate Data: yes
Initial Ready To Transfer (R2T): yes
Max Burst Length: 12582912
Max Outstanding R2T: 1
Max Receive Data Segment Length: 32768
Max Connections: 2
Header Digest: NONE
Data Digest: NONE
Man iscsiadm says :
The "Max Receive Data Segment Length" is returned from the target
side during login process. It can be set only at the target side
and is not subject to negotiation. This displayed value is observed
by the initiator side when transferring PDU's to the target side.
So here is my question :
Where to tune "Max Receive Data Segment Length" ? Unfortunately I can't find out...
Thank you very much for your support,
Best regards,
Ben