illumos: manual page: stmsboot.8

STMSBOOT(8) Maintenance Procedures STMSBOOT(8)

NAME

stmsboot - administration program for the Solaris I/O multipathing
feature

SYNOPSIS

/usr/sbin/stmsboot [[-d | -e [-D (fp | mpt) ]]
| -u | -L | -l controller_number]

DESCRIPTION

The Solaris I/O multipathing feature is a multipathing solution for
storage devices that is part of the Solaris operating environment. This
feature was formerly known as Sun StorEdge Traffic Manager (STMS) or
MPxIO.

The stmsboot program is an administrative command to manage enumeration
of multipath-capable devices with Solaris I/O multipathing. Solaris I/O
multipathing-enabled devices are enumerated under scsi_vhci(4D),
providing multipathing capabilities. Solaris I/O multipathing-disabled
devices are enumerated under the physical controller.

In the /dev and /devices trees, Solaris I/O multipathing-enabled devices
receive new names that indicate that they are under Solaris I/O
multipathing control. This means a device will have a different name from
its original name (after enabling) when it is under Solaris I/O
multipathing control. The stmsboot command automatically updates
/etc/vfstab and dump configuration to reflect the device names changes
when enabling or disabling Solaris I/O multipathing. One reboot is
required for changes to take effect.

OPTIONS

The following options are supported:

-e [ -D fp | mpt ]

Enables Solaris I/O multipathing on all supported multipath-capable
controller ports. Multipath-capable ports include fibre channel
(fp(4D)) controller ports and SAS (mpt(4D)) controller ports.
Following this enabling, you are prompted to reboot. During the
reboot, vfstab and the dump configuration will be updated to reflect
the device name changes. Specifying either -D mpt or -D fp limits the
enabling operation to ports attached using the specified driver.

-d [ -D fp | mpt ]

Disables Solaris I/O multipathing on all supported multipath-capable
controller ports. Multipath-capable ports include fibre channel
(fp(4D)) controller ports and SAS (mpt(4D)) controller ports.
Following this disabling, you are prompted to reboot. During the
reboot, vfstab and the dump configuration will be updated to reflect
the device name changes. Specifying either -D mpt or -D fp limits the
disabling operation to ports attached using the specified driver.

-u

Updates vfstab and the dump configuration after you have manually
modified the configuration to have Solaris I/O multipathing enabled
or disabled on specific multipath-capable controller ports. This
option prompts you to reboot. During the reboot, vfstab and the dump
configuration will be updated to reflect the device name changes.

-L

Display the device name changes from non-Solaris I/O multipathing
device names to Solaris I/O multipathing device names for multipath-
enabled controller ports. If Solaris I/O multipathing is not enabled,
then no mappings are displayed.

-l controller_number

Display the device name changes from non-Solaris I/O multipathing
device names to Solaris I/O multipathing device names for the
specified controller. If Solaris I/O multipathing is not enabled,
then no mappings are displayed.

USAGE

The primary function of stmsboot is to control the enabling and disabling
of Solaris I/O multipathing on the host. The utility automatically
updates vfstab(5) and dumpadm(8) configuration to reflect device name
changes. The system administrator is responsible for modifying
application configuration (for example, backup software, DBMS, and so
forth) to reflect updated device names.

The -L and -l options display the mapping between multipathed and non-
multipathed device names. These options function only after changes to
the Solaris I/O multipathing configuration have taken effect, that is,
following the reboot after invoking stmsboot -e.

ZFS datasets, including ZFS root datasets, are correctly handled by
stmsboot.

EXAMPLES

Example 1: Enabling Solaris I/O Multipathing

To enable Solaris I/O multipathing for all multipath-capable controllers,
run:

# stmsboot -e

To enable Solaris I/O multipathing on multipath-capable mpt(4D)
controller ports, enter:

# stmsboot -D mpt -e

To enable Solaris I/O Multipathing on multipath-capable fibre channel
controller ports, enter:

# stmsboot -D fp -e

Example 2: Disabling Solaris I/O Multipathing

To disable Solaris I/O multipathing on all multipath-capable controllers,
enter:

# stmsboot -d

To disable Solaris I/O multipathing on multipath-capable mpt(4D)
controller ports, enter:

# stmsboot -D mpt -d

To disable Solaris I/O multipathing on multipath-capable fibre channel
controller ports, enter:

# stmsboot -D fp -d

Example 3: Enabling Solaris I/O Multipathing on Selected Ports

To enable Solaris I/O multipathing on specific fibre channel controller
ports and disable the feature on others, manually edit the
/kernel/drv/fp.conf file. (See fp(4D).) The following command will update
vfstab(5) and dumpadm(8) configurations to reflect the changed device
names:

# stmsboot -u

A similar procedure involving the /kernel/drv/mpt.conf file should be
followed for devices attached by means of the mpt(4D) driver.

ATTRIBUTES

NOTES

Solaris I/O multipathing is not supported on all devices. After enabling
Solaris I/O multipathing, only supported devices are placed under Solaris
I/O multipathing control. Non-supported devices remain unchanged.

For Solaris releases prior to the current release, the -e and -d options
replace mpxio-disable property entries with a global mpxio-disable entry
in fp.conf.

Enabling Solaris I/O Multipathing on a Sun StorEdge Disk Array
The following applies to Sun StoreEdge T3, 3910, 3960, 6120, and 6320
storage subsystems.

To place your Sun StorEdge disk subsystem under Solaris I/O multipathing
control, in addition to enabling Solaris I/O multipathing, the mp_support
of the subsystem must be set to mpxio mode. The preferred sequence is to
change the subsystem's mp_support to mpxio mode, then run stmsboot -e. If
Solaris I/O multipathing is already enabled but the subsystem's
mp_support is not in mpxio mode, then change the mp_support to mpxio mode
and run stmsboot -u.

Refer to the Sun StorEdge Administrator's Guide for your subsystem for
more details.

Using ufsdump

The ufsdump(8) command records details of filesystem dumps in
/etc/dumpdates (see dumpdates(5)). Among other items, the entries contain
device names. An effect of the "active" stmsboot options (-e, -d, and -u)
is to change the device name of a storage device.

Because stmsboot does not modify dumpdates, entries will refer to
obsolete device names, that is, device names that were in effect before
Solaris I/O multipathing configuration changes were performed. In this
situation ufsdump will behave as if no previous dump of the filesystem
had been performed. A level 0 dump will be performed.

Procedure to Use stmsboot in Conjunction with Sun Cluster
If possible, invoke stmsboot -e before installing Sun Cluster software.
After executing stmsboot, install Sun Cluster software normally.

If Sun Cluster software is installed before executing stmsboot, follow
this procedure:

On each machine in the cluster where Solaris I/O multipathing is
required, execute:

# stmsboot -e

...and allow the system to reboot.

When the system comes up, enter the following two commands:

1. # /usr/cluster/bin/scdidadm -C

2. # /usr/cluster/bin/scdidadm -r

The preceding commands update did mappings with new device
names while preserving did instance numbers for disks that are
connected to multiple cluster nodes. did instance numbers of
the local disks might not be preserved. For this reason, the
did disk names for local disks might change.

3. Update /etc/vfstab to reflect any new did disk names for your
local disks.

4. Reboot the system.

To disable the Solaris multipathing feature, use stmsboot -d (instead of
stmsboot -e), then follow the procedure above.

To view mappings between the old and new device names, run stmsboot -L.
To view did device name mappings, run /usr/cluster/bin/scdidadm -L.

With active-passive storage arrays, it is possible that while your host
is rebooting the array controller could failover the path that a
particular target is using. In this scenario, fsck(8) will fail to open
the physical path listed in /etc/vfstab. The
svc:/system/filesystem/local:default SMF service will transition to a
maintenance state as a result. To rectify this, consult the documentation
for your storage array to failback the path. The mpathadm(8) can assist
with determining the active and passive path(s).

LIMITATIONS

On x86 platforms, the current Solaris release does not support disabling
Solaris I/O multipathing of boot devices attached by means of fibre
channel. Solaris I/O multipathing is always enabled for supported fibre
channel-attached boot devices. Disabling Solaris I/O multipathing in this
situation must be performed on a per-port basis. See fp(4D).

Executing devfsadm -C removes obsolete device entries that stmsboot
relies on. This will prevent correct operation of the -d option for boot
devices (regardless of platform type) and the -L option.

December 15, 2008 STMSBOOT(8)