On Fedora 25 with the 4.9 kernel, we run a VessRAID 1840i connected by iSCSI. Using rsnapshot and sync with nice and ionice, towards the end of the backup there are memory and kernel errors including:
kernel: connection1:0: ping timeout of 5 secs expired, recv timeout 5, last rx 76580624, last ping 76585814, now 76591204
kernel: connection1:0: detected conn error (1022)
iscsid: Kernel reported iSCSI connection 1:0 error (1022 - Invalid or unknown error code) state (3)
iscsid: connection1:0 is operational after recovery (1 attempts)
I posted on serverfault but wanted to see if anyone has any ideas?