nvme-stas
nvme-stas
Mr
Martin
Belanger
Dell, Inc.
nvme-stas
7
nvme-stas
NVMe over Fabrics STorage Appliance Services
Introduction
This page describes the services provided by the nvme-stas
package.
nvme-stas
is composed of two services, stafd8
and stacd8,
running on a host computer (the NVMe Host).
STorage Appliance Finder (stafd
)
The tasks performed by stafd
include:
Register for mDNS service type _nvme-disc._tcp
with Avahi, the service discovery daemon. This allows stafd
to automatically locate Central or Direct Discovery
Controllers (CDC, DDC) with zero-configuration networking
(zeroconf). stafd
also allows users to manually enter CDCs
and DDCs in a configuration file
(/etc/stas/stafd.conf) when users
prefer not to enable mDNS-based zeroconf.
Connect to discovered or configured CDCs or DDCs.
Retrieve the list of NVMe subsystem IO Controllers or
Discovery Controller referrals from the Discovery Log Page
using the NVMe command "Get Log Page".
Maintain a cache of the discovery log pages.
Provide a D-Bus API where other applications can interact
with stafd
. This API can be used, for example, to retrieve
the list of cached discovery log pages.
STorage Appliance Connector (stacd
)
The tasks performed by stacd
include:
Read the list of storage subsystems (i.e., discovery log pages)
from stafd
over the D-Bus API.
Similar to stafd
, stacd
can also read a list of storage
subsystems to connect to from a configuration
file: (/etc/stas/stacd.conf).
Set up the I/O controller connections to each storage subsystem.
Provide a D-Bus API where other applications can interact
with stacd
. For example, an application could retrieve the
list of I/O controllers that stacd
connected to.
System configuration
A host must be provided with a Host NQN and a Host ID. nvme-stas
will not run without these two mandatory configuration parameters.
To follow in the footsteps of nvme-cli
and libnvme
,
nvme-stas
will use the same Host NQN and ID that
nvme-cli
and libnvme
use by default.
In other words, nvme-stas
will read the Host NQN and ID
from these two files by default:
/etc/nvme/hostnqn
/etc/nvme/hostid
Using the same configuration files will ensure consistency between
nvme-stas
, nvme-cli
, and libnvme
.
On the other hand, nvme-stas
can operate with a
different Host NQN and/or ID. In that case, one can specify them
in /etc/stas/sys.conf.
A new optional configuration parameters introduced in TP8010, the
Host Symbolic Name, can also be specified in /etc/stas/sys.conf.
The documentation for /etc/stas/sys.conf
can be found /etc/stas/sys.conf.doc.
See Also
stacctl1,
stacd.conf5,
stacd.service8,
stacd8,
stafctl1,
stafd.conf5,
stafd.service8,
stafd8,