<div dir="ltr"><br><div>We started to notice that on our iSCSI hosts that are using Multipath that they seem to be sending most of the traffic across one port even though they have 4 paths for each mpath device. We are using a Hitachi SAN.</div>
<div><br></div><div>Here is my multipath configuration:</div><font face="courier new, monospace">defaults {<br> user_friendly_names yes<br>}<br><br>devices {<br> device {<br> vendor "HITACHI"<br>
product "DF.*"<br> path_grouping_policy multibus<br> path_checker tur<br> getuid_callout "/sbin/scsi_id -g -u -s /block/%n"<br>
no_path_retry 1<br> features "1 queue_if_no_path"<br> }<br>}</font><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace"><br>
</font></div><div><font face="courier new, monospace">The output of multipath looks like:</font></div><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace"><div>mpath2 (360060e80101af190058baee900000007) dm-6 HITACHI,DF600F</div>
<div>size=1.5T features='1 queue_if_no_path' hwhandler='0' wp=rw</div><div>`-+- policy='round-robin 0' prio=0 status=active</div><div> |- 8:0:0:1 sdg 8:96 active ready running</div><div> |- 9:0:0:1 sdh 8:112 active ready running</div>
<div> |- 7:0:0:1 sdf 8:80 active ready running</div><div> `- 10:0:0:1 sdi 8:128 active ready running</div><div>mpath0 (360060e80101af190058baee900000005) dm-5 HITACHI,DF600F</div><div>size=1.0T features='1 queue_if_no_path' hwhandler='0' wp=rw</div>
<div>`-+- policy='round-robin 0' prio=0 status=active</div><div> |- 9:0:0:0 sdd 8:48 active ready running</div><div> |- 8:0:0:0 sdc 8:32 active ready running</div><div> |- 10:0:0:0 sde 8:64 active ready running</div>
<div> `- 7:0:0:0 sdb 8:16 active ready running</div><div><br></div><div>However when I do a tcpdump and count the number of packets to each of the IQN's they are not equal, not even close.</div><div> <br>
</div><div>
<p class="">IQN1: 19,579</p>
<p class="">IQN2: 12,778</p>
<p class="">IQN3: 70,674</p>
<p class="">IQN4: 67<br></p><p class=""><br></p><p class="">Is there anything I need to do in order to ensure that Multipath balances more evenly across all the paths???</p><p class="">Any help would be appreciated.</p><p class="">
<br></p><p class="">Devin</p></div></font></div></div>