The SD card can be used instead of the internal flash memory of the switch to update or restore configuration settings. In addition, the SD card can be used to boot the switch. You can also copy IOS software and switch configuration settings from a PC or from the switch to the SD card, and then use the SD card to copy this software and settings to other switches.
When an SD card is formatted on the switch, the card is formatted with the Disk Operating System Filing System (DOSFS), a platform-independent industry-standard file system that is supported on various Cisco switches and routers.
The switch does not support third-party SD cards or SD High Capacity (SDHC) cards. Attempting to operate the switch with a non-supported card causes the following message to be displayed:
WARNING: Non-IT SD flash detected. Use of this card during normal operation can impact and severely degrade performance of the system. Please use supported SD flash cards only.
If the write-protect switch on the SD card is in the lock position, the switch can read data on the card and boot from the card, but updates and files cannot be written to the card.