As I tried to connect an additional server to my DataCore driven iSCSI SAN, the iSCSI initiator on the application server threw the error "Authentication required". Well, this error seems to be related to CHAP so I checked the CHAP settings on the iSCSI target port but as expected, there is no CHAP configured at all.
My DataCore server has 4 iSCSI traget ports and this error only pops up on two of them. Using the other two ports works perfectly.
After digging a bit deeper I found that this error isn't related to authentication/CHAP at all.
SSY-V has a default limit of 16 iSCSI initiator connections per target port. This limit is even mentioned in the SSY-V manual...
"By default, no more than 16 iSCSI initiator connections are allowed to an iSCSI target at any one time."
If you try to add a 17th initiator, this error will be reported.
The "by default" part could be interpreted as there is a way to raise this limit but I haven't found anything in the GUI that could do the job. So probably if you really need to higher this limit you have to contact DataCore support so they will guide you. But I think there is a good reason for this limit and especially in a 1GbE environment one should rather add additional NICs.
I really work a lot with SSY-V (mostly in FC environments) but I hadn't have a clue about this limit.
So keep that in mind, especially if you design a bigger iSCSI environment and plan for enough NIC ports if you want to have more than 16 servers attached.