Linux iSCSI Network Setup for Lyve Mobile Rackmount Receiver

You can use lmacli to configure an iSCSI data path between a Linux host and a Lyve Mobile Rackmount Receiver connected to the same data network.

The following steps are required:

1. Install the required packages on Linux.
2. Configure the network interfaces used for iSCSI with static IP addresses on Linux.
3. Configure Lyve Mobile Rackmount Receiver for iSCSI.
4. Check for network connectivity between the host and the Lyve Mobile Rackmount Receiver.
5. Connect the software iSCSI initiator on the host to the iSCSI target.
6. Configure I/O multipath to improve I/O bandwidth.

Install Open-iSCSI and multipath-tools on Linux

Red Hat Enterprise Linux

To install Open-iSCSI and multipath tools:

1. On the Linux station, open a terminal session.
2. Enter the following command:

sudo yum install lsscsi device-mapper-multipath iscsi-initiator-utils

Ubuntu/Debian

To install Open-iSCSI and multipath tools:

1. On the Linux station, open a terminal session.
2. Enter the following command:

sudo apt install lsscsi multipath-tools open-iscsi

Configure host network interfaces

The iSCSI data path between the Linux host and the Lyve Mobile Rackmount Receiver is made of 1-4 network interfaces. On the Linux host, the network interfaces used to transport iSCSI traffic should be configured with static IP addresses.

Identify a network port

You can visually identify a network interface by blinking its LED.

To identify a network port:

1. On the Linux station, open a terminal session.
2. Enter the following command to visually identify a network interface:

sudo ethtool --identify interface name

where interface name is a network interface on the Linux host, for example:

sudo ethtool --identify eno1

Configure static IP addresses with netplan

Netplan is the network configuration abstraction renderer used by Ubuntu Server.

Below is a sample configuration file for Netplan to set static IP addresses on 4 network ports and enable jumbo frames of 9000 bytes.

Configure static IP addresses with NetworkManager

NetworkManager is the network management daemon used by Red Hat Enterprise Linux or Ubuntu Desktop.

nmcli is a command-line interface for the NetworkManager daemon. The following is an example of using nmcli to create a network connection with a static IP address and jumbo frames.

1. On the Linux station, open a terminal session.
2. Enter the following command to list network interfaces:

nmcli device

3. Add a network connection by entering the following:

nmcli connection add type ethernet ifname interface name ipv4.method manual ipv4.addr "IP address" 802-3-ethernet.mtu 9000

where interface name is a Rackmount Receiver iSCSI port and IP address is a Rackmount Receiver port IP address, for example:

nmcli connection add type ethernet ifname enp108s0f0 ipv4.method manual ipv4.addr "192.168.0.1/24" 802-3-ethernet.mtu 9000

4. Confirm that the settings have been applied by entering the following the following:

nmcli device show

Configure Lyve Mobile Rackmount Receiver for iSCSI

lmacli info with iSCSI

The connection type for your Lyve Mobile Array is displayed as iSCSI.

To view device details:

1. On the Linux station, open a terminal session.
2. Enter the following:

lmacli info IP address

where IP address is a Rackmount Receiver port IP address, for example:

lmacli info 192.168.0.100

Create the iSCSI configuration file for lmacli

lmacli reads the iSCSI configuration for a Lyve Mobile rackmount Receiver from a file. You can edit the file to modify the iSCSI configuration of a Lyve Mobile Rackmount Receiver.

An example iSCSI configuration file is included in the lmacli package.

• Linux—The example iSCSI configuration file is installed in /usr/share/doc/lmacli/examples/lmacli-rackmount-iscsi.conf.
• Windows—The example iSCSI configuration file is contained in lmacli's release Zip archive.

Copy the example iSCSI configuration file and modify the copy to match your environment.

Note some important iSCSI parameters:

• allowed_initiators—Contains the IQN of the initiators allowed to connect to the Lyve Mobile Array Rackmount Receiver iSCSI target.
• Linux—The IQN of the software initiator is set in the following file: /etc/iscsi/initiatorname.iscsi.
• Windows—The IQN of the software initiator can be obtained from the control panel: Control Panel > iSCSI Initiator > Configuration > Initiator name.
• jumbo_frame—Enabling jumbo frames provides a performance boost.

Below is an iSCSI configuration file for LMACLI that enables jumbo frames and configures the network ports reserved for iSCSI traffic so that they all belong to different subnets.

Apply the iSCSI configuration with lmacli

To apply the iSCSI configuration:

1. On the Linux station, open a terminal session.
2. Enter the following:

lmacli rackmount-setup --iscsi-config my-server.conf IP address

where IP address is a Rackmount Receiver port IP address, for example:

lmacli rackmount-setup --iscsi-config my-server.conf 192.168.0.100

Check for network connectivity between the host and Rackmount Receiver

Checking for network connectivity between the host and the Lyve Mobile Rackmount Receiver may eliminate future issues. Each rackmount receiver port declared in the iSCSI configuration file should be tested with the ping command.

To check network connectivity for jumbo frames:

1. On the Linux station, open a terminal session.
2. Enter the following command:

ping -s 8972 IP address

where IP address is a Rackmount Receiver port IP address declared in the iSCSI configuration file, for example:

ping -s 8972 192.168.0.100

Connect the iSCSI initiator on the host to the iSCSI target

Discover the iSCSI target

The iSCSI target on the Lyve Mobile Rackmount Receiver can be discovered with the iscsiadm command. The --portal parameter should be set to one of the IP addresses declared in lmacli's iSCSI configuration file.

To discover the iSCSI target:

1. On the Linux station, open a terminal session.
2. Enter the following command:

sudo iscsiadm --mode discovery --type sendtargets --portal IP address

where IP address is a Rackmount Receiver port IP address declared in the iSCSI configuration file, for example:

sudo iscsiadm --mode discovery --type sendtargets --portal 192.168.0.100

Log in to the iSCSI target

The iscsiadm command can also be used to connect the iSCSI initiator to the iSCSI target through all its portals.

To log in to the iSCSI target:

1. On the Linux station, open a terminal session.
2. Enter the following command:

sudo iscsiadm --mode node --target IQN --login

where IQN is an iSCSI Qualified Name obtained from the discover command, for example:

sudo iscsiadm --mode node --target iqn.1995-03.com.dothill:01.array.00c0fff39296-624ebda2.a --login

The lsscsi command can be used to display the block devices. Each block device listed represents a path to the same LUN.

The multiple paths to the device are coalesced by the device mapper multipath daemon.

See below for details on configuring I/O multipath for a Lyve Mobile Rackmount Receiver.

Configure I/O multipath to improve I/O bandwidth

The role of the device mapper multipath daemon is to detect and coalesce multiple paths to devices, for fail-over or performance reasons.

To display the list of multipath devices:

1. On the Linux station, open a terminal session.
2. Enter the following:

sudo multipath -ll

To improve I/O bandwidth, it is recommended to change the path_grouping_policy parameter from the default failover to group_by_prio. To set the path_grouping_policy to group_by_prio for all Lyve Mobile Arrays, add the following snippet to /etc/multipath.conf:

After restarting the device mapper multipath daemon, the output of multipath -ll appears as follows:

The first line starts with the multipath device name (mpatha in the example above). The full path to the device is /dev/mapper/mpatha.