Turn your flash card into an ATA drive

The flash memory available in newer router platforms (at the very minimum the ISR routers and 37xx series) is capable of being used as a regular disk drive (for example, to store system logging information), but it might be formatted as a traditional Low-End File System (LEFS) flash card (more likely if the router was not manufactured recently). To change the flash card format to disk-like FAT32 format, use the format flash: privileged-level command (and don't forget to store the IOS image to another location before formatting the flash). After the format process is complete, you can create subdirectories on the flash: memory and use it as a regular disk device. A sample formatting operation is displayed below:
fw#format flash:
Format operation may take a while. Continue? [confirm]
Format operation will destroy all data in "flash:". Continue? [confirm]
Enter volume ID (up to 64 chars)[default flash]:
Current Low End File System flash card in flash will be formatted into DOS File System flash card!
Continue? [confirm] y

Format: Drive communication & 1st Sector Write OK...
Writing Monlib sectors.
Monlib write complete

Format: All system sectors written. OK...

Format: Total sectors in formatted partition: 125297
Format: Total bytes in formatted partition: 64152064
Format: Operation completed successfully.

Format of flash complete

fw#show file system | include flash
* 64012288 27734016 disk rw flash:#


  1. Just an FYI, I tried once to use a CF card-to-PCMCIA adapter on a 1602 router to see if the router would see it. The router kicked out an error indicating there was something missing (I assume there is a special IC in the Cisco-approved PCMCIA flash cards) and kicked out an error and froze - no boot, nothing. It isn't entirely related to the post but should show the older Cisco gear appears to have some specific requirements for flash used on the devices that newer gear (x800s, etc) doesn't.
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