Some instances, the iscsi connection fails. This may be due to swap space. Adding a swap file can help. How to create a swap file.

Pre-9.3 NAS loses iSCSI or NFS/CIFS connectivity arbitrarily

From NAS /var/log/messages:
Aug 15 22:24:01 nas kernel: pid 29173 (smbd), uid 65534, was killed: out of swap space
Aug 15 22:27:11 nas kernel: arp: 10.132.29.129 moved from 00:25:90:a1:47:6e to 3e:c6:19:01:9d:8d on em0
Aug 15 22:27:16 nas kernel: arp: 10.132.29.129 moved from 3e:c6:19:01:9d:8d to 00:25:90:a1:47:6e on em0
Aug 15 22:35:01 nas kernel: pid 29365 (smbd), uid 65534, was killed: out of swap space
Aug 15 22:44:57 nas kernel: pid 29453 (smbd), uid 65534, was killed: out of swap space

Cause:
No swap file.

Resolution:
Created a swap file.

dd if=/dev/zero of=/mnt/vol1/swap0 bs=1m count=8192;
chmod 0600 /mnt/vol1/swap0;

[root@nas] /mnt/vol1# mdconfig -a -t vnode -f /mnt/vol1/swap0
md3

[root@nas] swapon /dev/md3