HP 3PAR Ubuntu Operating System Implementation Guide

Setting Up iSCSI for Ubuntu
iSCSI timers and session parameters are specified in the /etc/iscsi/iscsid.conf file.
You can adjust the iSCSI timers for better SAN performance.
The replacement_timeout iSCSI timeout parameter prevents I/O errors from propagating to
the application by controlling how long the iSCSI layer should wait for a timed-out path/session
to re-establish itself before failing any commands on it. The default replacement_timeout value
is 120 seconds.
To adjust replacement_timeout, complete the following steps:
1. Open /etc/iscsi/iscsid.conf and edit the following line:
node.session.timeo.replacement_timeout = [replacement_timeout]
Set this parameter to 5 seconds for a faster failover.
node.session.timeo.replacement_timeout = 5
2. Change the time interval to wait for a connection before sending a ping:
node.conn[0].timeo.noop_out_interval = [noop_out_interval]
This allows for more time for the connections that were broken to be re-established before a
ping is sent out (in case of a bad cable or a broken link).
Set this parameter to 10 seconds for a ping to succeed after a connection is made:
node.conn[0].timeo.noop_out_interval = 10
3. To set the host log into the iSCSI nodes every time the iSCSI daemon is started or the host is
rebooted, edit the iSCSI configuration in /etc/iscsi/iscsid.conf and change the values
of the following default settings:
node.startup = automatic
node.conn[0].startup = automatic
NOTE: The node.conn[0].startup variable is optional and not defined in the default
iscsid configuration file.
4. Use cat /etc/init.d/open-iscsi to show the start/stop run-levels for open-iscsi.
# cat /etc/init.d/open-iscsi
#! /bin/sh
### BEGIN INIT INFO
# Provides: iscsi
# Required-Start: $local_fs
# Required-Stop: $remote_fs sendsigsnetworking
# Default-Start: S
# Default-Stop: 0 6
# Short-Description: Starts and stops the iSCSI initiator services and logs in
to default targets
### END INIT INFO
<…>
5. Verify that the appropriate rc scripts have been created for each run level. The start number(s)
may not match those shown here:
# ls -1 /etc/rc?.d/S*open-iscsi
/etc/rc0.d/S41open-iscsi
Connecting a Host Server with iSCSI 11