Linux SAS/FC Network Setup for Lyve Mobile Rackmount Receiver

You can use lmacli to configure a SAS or FC 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 Rackmount Receiver for SAS or FC.
3. Scan for new disks on Linux.
4. Configure I/O multipath to improve I/O bandwidth.

Install multipath tools on Linux

Red Hat Enterprise Linux

To install multipath tools:

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

sudo yum install lsscsi device-mapper-multipath

Ubuntu/Debian

To install multipath tools:

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

sudo apt install lsscsi multipath-tools

Configure Lyve Mobile Rackmount Receiver for SAS/FC

lmacli info with SAS/FC

The connection type for your Lyve Mobile Array is displayed as SAS or FC.

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

Apply the SAS/FC configuration with lmacli

To apply the configuration:

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

lmacli rackmount-setup IP address

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

lmacli rackmount-setup 192.168.0.100

Scan for new disks on Linux

Display storage devices

To view connected storage devices:

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

lsscsi

If the host is equipped with a dual-port SAS or FC host bus adapter, Linux should display two enclosures. Each enclosure may contain a disk if the cable connects the host to the corresponding ports on Rackmount Receiver. The enclosures and disks associated with the Lyve Mobile Array volume have their vendor attribute set to SEAGATE and their model starts with STJX.

If enclosures are displayed but no disk is associated with them, the host storage configuration must be rescanned in order to refresh the configuration.

Rescan SAS/FC bus

To refresh the configuration:

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

rescan-scsi-bus.sh

Following the rescan, a summary of the storage configuration changes is displayed. In the example above, two new disks are detected (one for each enclosure).

Enter lsscsi again to display the block device associated with each disk:

Each disk listed in the example above represents a distinct path to the same LUN exported by the Lyve Mobile Array.

The multiple paths to the device are coalesced by the device mapper multipath daemon. See Configure I/O multipath to improve I/O bandwidth below.

Configure I/O multipath to improve I/O bandwidth

The device mapper multipath daemon detects and coalesces multiple paths to devices for failover or performance purposes.

Display multipath devices

To display multipath devices:

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

sudo multipath -11

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 policy to group_by_prio for all Lyve Mobile Arrays, add the following snippet to /etc/multipath.conf:

devices {
            device {
                       vendor "SEAGATE"
                       product "STJX.*"
                       path_grouping_policy "group_by_prio"
            }
}

After restarting the device mapper multipath daemon, the result of the multipath -11 command should look like this:

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