This article provides information on the sizes of USB devices successfully tested on the SRX firewall platforms. 

We recommend using USB memory sticks with storage capacities as listed below for SRX Series devices:

• 4 GB
• 8 GB
• 16 GB
• 32 GB

All USB flash drives used on SRX Series devices must have the following features:

• USB 2.0 or later.
• Formatted with a FAT/FAT 32 or MS-DOS file system

Caution: Any USB memory size not listed as recommended for SRX Series devices has not been tested by Juniper Networks. Juniper Networks Technical Assistance Centre (JTAC) can provide only limited support for issues related to non-recommended hardware. We strongly recommend that you use only the above-mentioned USB flash drive sizes.

• For Upgrade procedure using a USB drive, please refer to  KB16652 [juniper.net]
• To mount/unmount USB into the SRX platform, please refer to KB12880 [juniper.net]
• For USB auto-installation procedure, please refer to KB23882 [juniper.net]

2020-1-29: Minor non-technical edit.

• [SRX] USB autoinstallation on SRX branch platforms for software upgrade/downgrade
• [EX/SRX/MX/QFX] How to mount a USB drive on the EX/SRX/MX series platforms
• SRX Getting Started - Junos Software Installation/Upgrade