Using Fast Reboot

The following tasks apply to both the SPARC and x86 platform, unless otherwise specified.

How to Initiate a Fast Reboot of a SPARC Based System

Use the following procedure to fast reboot a SPARC based system when the config/fastreboot_default property of the boot-config service is set to false, which is the default behavior. To change the default behavior of the Fast Reboot feature, so that a fast reboot is automatically performed when the system reboots, see Managing the Boot Configuration Service.

1. Assume the root role.
2. Initiate a fast reboot of the system by typing the following command:

   # reboot -f

How to Initiate a Fast Reboot of an x86 Based System

1. Assume the root role.
2. In a terminal window, initiate a fast reboot of the system by typing either of the following commands:

   # reboot

   # init 6

x86: How to Fast Reboot a System to the nth Entry in the GRUB menu.lst File

The boot entries in the menu.lst file have a corresponding number that you can specify with the reboot command.

1. Assume the root role.
2. In a terminal window, list the boot entries that are on the system, along with their corresponding numbers.

   # bootadm list-menu
   the location for the active GRUB menu is: /rpool/boot/grub/menu.lst
   default 1
   0 Oracle Solaris
   1 Oracle Solaris 10
   2 zfsbe2
   3 BE3

3. Fast reboot the system by specifying the number of the boot entry.

   # reboot entry-number

   For example, to reboot the entry, zfsbe2, you would type:

   # reboot 2

Example 7-8 x86: Fast Rebooting a System to the nth Entry in the menu.lst File

The following example shows how to fast reboot to the zfsbe2 BE by specifying its corresponding entry number.

# bootadm list-menu
the location for the active GRUB menu is: /rpool/boot/grub/menu.lst
default 1
0 Oracle Solaris 11
1 Oralce Solaris 10
2 zfsbe2
3 BE3

# reboot 2

x86: Initiating a Fast Reboot of a System by Specifying an Alternate Boot Environment

There are several ways that you can perform a fast reboot of an x86 based system to an alternate BE. The following examples illustrate some of these methods.

Example 7-9 x86: Fast Rebooting a System by Specifying a Newly Activated BE

The following example shows how to fast reboot a system to a newly activated BE, oraclesolaris-4.

# bootadm list-menu
the location for the active GRUB menu is: /rpool/boot/grub/menu.lst
default 1
0 oracle solaris
1 oraclesolaris-4
2 zfsbe2
3 BE3

# beactivate oraclesolaris-4
# reboot

Example 7-10 x86: Fast Rebooting a System by Specifying an Alternate BE

To fast reboot a system to an alternate BE, for example zfsbe1, you would type:

# reboot -- 'rpool/zfsbe1'

To fast reboot a system to a dataset named rpool/zfsbe1, you would type:

# reboot -- 'rpool/zfsbe1'

To fast reboot a system to an alternate ZFS root dataset, you would type:

# reboot -- 'rpool/ROOT/zfsroot2'

Example 7-11 x86: Fast Rebooting a System to an Alternate BE in 64–Bit Mode

To fast reboot a system to the zfsbe3 BE, in 64-bit mode with the kernel debugger enabled, you would type:

# reboot -- 'rpool/zfsbe3 /platform/i86pc/kernel/amd64/unix -k'

Example 7-12 x86: Fast Rebooting a System to a New 64–Bit Kernel

To fast reboot a system to a new 64–bit kernel named my-kernel, you would type:

# reboot -- '/platform/i86pc/my-kernel/amd64/unix -k'

Example 7-13 x86: Performing a Fast Reboot of a Mounted Disk or a Mounted Dataset

To perform a fast reboot of a mounted disk or a mounted dataset, you would type:

# reboot -- '/mnt/platform/i86pc/my-kernel/amd64/unix -k'

Example 7-14 x86: Fast Rebooting a System in Single-User Mode With the Kernel Debugger Enabled

To fast reboot a system in single-user mode with the kernel debugger enabled, you would type:

# reboot -- '-ks'

Performing a Slow Reboot of a System

To reboot a SPARC or x86 based system that has Fast Reboot enabled by default, without reconfiguring the boot-config service to disable the feature, use the -p option with the reboot command, as shown in the following example:

# reboot -p

Managing the Boot Configuration Service

Starting with the Oracle Solaris 11 Express release, Fast Reboot is supported on the SPARC platform, as well as the x86 platform. On both platforms, this feature is controlled by the SMF and implemented through a boot configuration service, svc:/system/boot-config. The boot-config service provides a means for setting or changing the default boot configuration parameters.

The fastreboot_default property of the boot-config service enables an automatic fast reboot of the system when either the reboot or the init 6 command is used. When the config/fastreboot_default property is set to true the system automatically performs a fast reboot, without the need to use the reboot -f command. By default, this property's value is set to false on the SPARC platform and to true on the x86 platform.

On the x86 platform, an additional property, config/fastreboot_onpanic, is implemented by default. This property enables a fast reboot of an x86 system in the event of a system panic.

The properties that are part of the boot-config service can be configured by using the svccfg and svcadm commands.

The following example shows how to set the property's value to true on the SPARC platform, so that a fast reboot is initiated by default:

# svccfg -s "system/boot-config:default" setprop config/fastreboot_default=true
# svcadm refresh svc:/system/boot-config:default

The following example shows how to disable the default behavior of the fastreboot_onpanic property on an x86 based system by setting the property's value to false:

# svccfg -s "system/boot-config:default" setprop config/fastreboot_onpanic=false
# svcadm refresh svc:/system/boot-config:default

Note that on the x86 platform, changing one property's default behavior does not affect the default behavior of the other property.

For information about managing the boot configuration service through the SMF, see the svcadm(1M) and the svccfg(1M) man pages.

x86: Debugging Early Panics That Might Occur

Because the boot-config service has dependencies on the multiuser milestone, users who need to debug early panics can patch a global variable, fastreboot_onpanic in the /etc/system file, as shown in the following example:

# echo "set fastreboot_onpanic=1" #x26;#x26;#x3e;#x26;#x26;#x3e; /etc/system
# echo "fastreboot_onpanic/W" | mdb -kw

x86: Troubleshooting Conditions That Might Prevent Fast Reboot From Working

The following are possible conditions under which the Fast Reboot feature might not work:

• GRUB menu cannot be processed.

• Driver does not implement the quiesce function.

  If you attempt a fast reboot of a system with an unsupported driver, a message similar to the following is displayed:

  Sep 18 13:19:12 too-cool genunix: WARNING: nvidia has no quiesce()
  reboot: not all drivers have implemented quiesce(9E)

  If the graphics drivers are the only drivers that do not support the quiesce function, you can attempt to force a fast reboot by running the following commands:

  # echo "force_fastreboot/W 1" | mdb -kw# echo "set force_fast \
  reboot = 1" #x26;#x26;#x3e;#x26;#x26;#x3e; /etc/system

  ---

  Note - If the driver for the network interface card (NIC) does not implement the quiesce function, try to unplumb the interface first, then attempt a fast reboot of the system.

  ---

• Insufficient memory

  If there is not enough memory on the system, below 1G (0x40000000) for building the page tables, or not enough free memory to load the new kernel and the boot archive, the fast reboot attempt fails with the following messages, then falls back to a regular reboot.

  Fastboot: Couldn't allocate size below PA 1G to do fast reboot
  Fastboot: Couldn't allocate size below PA 64G to do fast reboot

• Unsupported environment

  Fast reboot functionality is not supported in the following environments:

  • An Oracle Solaris release that is running as a paravirtualized (PV) guest domain

  • Non-global zones

For more information, see the following man pages:

• reboot(1M)

• init(1M)

• quiesce(9E)

• uadmin(2)

• dev_ops(9S)