DLPX-87360 reduce deadman timer to quickly detect hung socket connection (#458)

Author: grwilson

files/common/lib/modprobe.d/10-zfs.conf

@@ -122,3 +122,12 @@ options zfs zfs_vdev_open_timeout_ms=180000
 # VDB errors (e.g. MSSQL VDB refresh failing).
 #
 options zfs zvol_open_timeout_ms=60000
+
+#
+# The deadman timer is typically used to detect if an I/O is hung.
+# On object store pools, the deadman timer check for a hung socket
+# connections between the kernel and the agent. Reducing this
+# to 1 minute will allow the kernel to detect this condition quickly
+# and restart the agent if the connection is hung.
+#
+options zfs zfs_deadman_synctime_ms=60000