S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
20-52
Cisco MDS 9000 Family Troubleshooting Guide, Release 3.x
OL-9285-05
Chapter 20 Troubleshooting IP Storage Services
iSCSI TCP Performance Issues
Node WWN is 20:00:00:0c:30:57:5e:c2 (dynamic)
Member of vsans: 777, 778
Number of Virtual n_ports: 1
Virtual Port WWN is 20:05:00:0c:30:6c:24:42 (configured)
Interface iSCSI 2/1, Portal group tag: 0x1001
VSAN ID 778, FCID 0x7c0000
VSAN ID 777, FCID 0x610001
MDS_BOTTOM#
show iscsi local
target: shark_nas
Port WWN 50:05:07:63:00:c8:94:4c
(This is the port of the Shark connected to MDS 9216_Bottom.)
Secondary PWWN 50:05:07:63:00:c4:94:4c
(This is the port of the Shark connected to MDS 9216_Top.)
Configured node
No. of LU mapping: 2
iSCSI LUN: 0000, FC LUN: 0000
iSCSI LUN: 0001, FC LUN: 0001
No. of initiators permitted: 1
initiator iqn.1987-05.com.cisco:02.75af2f95624c.shark-nas is permitted
all initiator permit is disabled
MDS_BOTTOM#
MDS_BOTTOM# show interface iscsi 2/1
iscsi2/1 is up
Hardware is GigabitEthernet
Port WWN is 20:41:00:0c:30:57:5e:c0
Admin port mode is ISCSI
Port mode is ISCSI
Speed is 1 Gbps
Number of iSCSI session: 2, Number of TCP connection: 2
Configured TCP parameters
Local Port is 3260
PMTU discover is
enabled
(default)
(This is especially required if there are devices without jumbo support in the path. The initial TCP 3-way
handshake will establish a session with a high MSS value (provided both the IPS module and the iSCSI
client are configured or capable) even if there are devices without jumbo frame support in the path.
Without PMTU discovery, there will be problems.)
Keepalive-timeout 60
Initial-retransmit-time 300
(If there is high delay between the peers, this parameter that can be adjusted. There’s no real formula;
instead use trial and error to find the optimum value for your network. Try lower values as well as higher
ones, and get hints from the
show ips stats tcp
output.)
Max-retransmissions 8
Window-size
1024000
Sack is enabled
Forwarding mode: pass-thru
5 minutes input rate 410824 bits/sec, 51353 bytes/sec, 1069 frames/sec
5 minutes output rate 581291520 bits/sec, 72661440 bytes/sec, 53302 frames/sec
iSCSI statistics
1072393 packets input, 51482588 bytes
1072305 Command pdus, 0 Data-out pdus, 0 Data-out bytes, 0 fragments
53430805 packets output, 72837086312 bytes
1072273 Response pdus (with sense 9), 0 R2T pdus
52358444 Data-in pdus, 70272402880 Data-in bytes
MDS_BOTTOM#
show iscsi remote initiator iqn.1987-05.com.cisco:02.75af2f95624c.shark-nas
iscsi tcp
