The Warm Reload feature allows users to reload their routers without reading images from storage. That is, the Cisco IOS image reboots without ROM monitor mode (ROMMON) intervention by restoring the read-write data from a previously saved copy in the RAM and by starting execution without either copying the image from flash to RAM or self-decompression of the image. Thus, the overall availability of your system improves because the time to reboot your router is significantly reduced.
Release Modification
12.3(2)T
This feature was introduced.
12.2(18)S
This feature was integrated into Cisco IOS Release 12.2(18)S.
For detailed information about this feature, see the following Cisco document:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5413/prod_bulletin09186a008020fd72.html
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_2/gtwrmrbt.htm