Two of three ESXi 6.0 hosts are unable to connect to Synology datastore

[jobee1]

Good afternoon, 

I recently purchased a Synology RS819 NAS to use as an iSCSI datastore for three HP (all the same hardware) ESXi 6.0 (moving to 6.7 soon) hosts. I was able to get one of the hosts to connect to it but I'm unable to get the other two to connect. On those other two I can navigate to Properties under iSCSI Software Adapter and after adding the Synology to the Dynamic Discovery tab I can see it in the Static Discovery tab; it even pulls up the correct target name. BUT, if I go to Storage and click on Rescan All... there's no Synology. All three hosts are running ESXi 6.0.0 HPE 13635687. I'm not a VMware expert so if I'm missing something simple please don't hesitate to point it out to me. 

Thanks, 

Joe B 

[jobee1]

Ok, I just found this error: 

Login to iSCSI target iqn.2000-01.com.synology:OS-VMNAS.Target-1.6f82582699 on vmhba33 @ vmk2 failed. Target returned login error of: 0002.

I looked up the error 0002 and found nothing. 

Thanks, 

Joe B 

[jobee1]

And this: 

Login to iSCSI target iqn.2000-01.com.synology:OS-VMNAS.Target-1.6f82582699 on vmhba33 @ vmk2 failed. The iSCSI initiator could not establish a network connection to the target.

Thanks, 

Joe B 

[jobee1 · Accepted solution]

I finally found my answer. On the Synology NAS go to iSCSI Manager > Target > Action (button) > Edit > Advanced > and check the Allow Multiple Sessions box. I'm grateful it was one of the easiest fixes I've done. I hope this helps others. 

Thanks, 

Joe B