Please re-flash the iSCSI module again with 1.72, you have very minimal space left.

Also I see unconfigured Volume replication tasks - are you using these? Could be part of the reason for the Snapshot issue.

The Execute_task_management errors means that the Initiator was not reachable for a while.
We export it to critical errors because sometimes this behavior can damage file system or data if packet errors exist on the test.log file then this error is generated. Also caused by bond issues from NIC, switch or network.
If this is happening for the iSCSI-R3 Enterprise as well like you stated then we will need to see these logs as well to verify.

Aug 7 07:16:56 iSCSI-T kernel: execute_task_management(1236) 39eafdb 5 ffffffff
Aug 7 07:16:57 iSCSI-T kernel: execute_task_management(1236) 1cf6447 5 ffffffff