Juniper Networks J-Series manual Option Description Partition, Root-size size, Swap-size size

J-series™ Services Router Administration Guide

Table 98: CLI request system snapshot Command Options (continued)

Option	Description
partition	Partitions the medium. This option is usually necessary for boot devices that do not have software
	already installed on them.
root-size size	Specifies the size of the root partition, in megabytes. The default value is the boot device's physical
	memory minus the config, data, and swap partitions.
	The root partition is mounted on / and does not include configuration files.
	This option also partitions the boot medium.
swap-size size	Specifies the size of the swap partition, in megabytes. The default value is one-third of the physical
	memory on a boot medium larger than 128 MB, or 0 MB on a smaller boot device.
	The swap partition is used for swap files and software failure memory snapshots. Software failure
	memory snapshots are saved to the boot medium only if it is specified as the dump device. For
	information about the setting the dump device, see “Configuring a Boot Device to Receive
	Software Failure Memory Snapshots” on page 190.
	NOTE: This option also partitions the boot medium.

Configuring a Boot Device to Receive Software Failure Memory Snapshots

You can use the set system dump-deviceCLI command to specify the medium to use for the Services Router to store system software failure memory snapshots. In this way, when the operating system fails, if you have specified a system dump device in the configuration, the operating system preserves a snapshot of the state of the router when it failed.

After you reboot the system, the dump device is checked for a snapshot as part of the operating system boot process. If a snapshot is found, it is written to the crash dump directory on the router (/var/crash). The customer support team can examine this memory snapshot to help determine the cause of the system software failure.

NOTE: If the swap partition on the dump device medium is not large enough for a system memory snapshot, either a partial snapshot or no snapshot is written into the crash dump directory.

Enter the set system dump-deviceCLI command with the following syntax:

user@host> set system dump-device boot-device compact-flash removable-compact-flash usb

Table 99 on page 191 describes the set system dump-devicecommand options.

190■ Configuring Boot Devices