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Table Of Contents
Information About Warm Upgrade
How to Reload a Cisco IOS Image Using the Warm Upgrade Functionality
Reloading a Cisco IOS Image Using the Warm Upgrade Functionality
Monitoring and Troubleshooting the Warm Upgrade Functionality
Configuration Examples for the Warm Upgrade Feature
Reloading a Cisco IOS Image Using the Warm Upgrade Functionality: Example
Warm Upgrade
The Warm Upgrade feature provides the capability for a Cisco IOS image to read and decompress another Cisco IOS image and then transfer control to this new image. This functionality reduces the downtime of a device during planned Cisco IOS software upgrades or downgrades. The Warm Upgrade feature is complementary with the Warm Reload feature introduced in Cisco IOS Release 12.3(2)T.
Feature History for the Warm Upgrade Feature
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents
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Information About Warm Upgrade
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Information About Warm Upgrade
To use the Warm Upgrade feature, you should understand the following concept:
Warm Upgrade Functionality
The Warm Upgrade feature provides the capability for a Cisco IOS image to read and decompress another Cisco IOS image and then transfer control to this new image. This functionality reduces the downtime of a device during planned Cisco IOS software upgrades or downgrades. To perform a warm upgrade, use the reload warm file url command. The Warm Upgrade feature is complementary with the Warm Reload feature introduced in Cisco IOS Release 12.3(2)T.
Prior to the Warm Upgrade feature, a Cisco IOS image transferred control to ROM monitor mode (ROMMON) to perform a Cisco IOS software upgrade or downgrade. ROMMON, along with the help of the boot loader image, carried out the required upgrade or downgrade procedures. While this process is in progress, the networking device is down. With the introduction of the Warm Upgrade feature, packet forwarding is able to continue while the new Cisco IOS image is read and decompressed. The device is down only when the current image is overwritten with the new image, and the new image loads and reconfigures the operating system.
If a warm upgrade operation fails, the current Cisco IOS image should continue to run unless it has been partly or fully overwritten. In this case, ROMMON is allowed to load any image that is configured.
Note
How to Reload a Cisco IOS Image Using the Warm Upgrade Functionality
This section contains the following procedures:
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Reloading a Cisco IOS Image Using the Warm Upgrade Functionality
Perform this task to reload a Cisco IOS image using the warm upgrade functionality.
Prerequisites
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Restrictions
A software upgrade or downgrade using the warm upgrade functionality can only be performed if there is enough free memory in the system to accommodate a decompressed Cisco IOS image.
SUMMARY STEPS
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DETAILED STEPS
Monitoring and Troubleshooting the Warm Upgrade Functionality
Perform this task to monitor and troubleshoot the warm upgrade functionality.
SUMMARY STEPS
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DETAILED STEPS
Configuration Examples for the Warm Upgrade Feature
This section provides the following configuration example:
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Reloading a Cisco IOS Image Using the Warm Upgrade Functionality: Example
The following example shows how to reload the operating system with a new image whose location and name is tftp://9.1.0.1/c7200-p-mz.port. The reload is performed using the warm upgrade functionality.
Router> reload warm file tftp://9.1.0.1/c7200-p-mz.portProceed with reload? [confirm]Loading c7200-p-mz.port from 9.1.0.1 (via Ethernet5/0):!!![OK - 15323964 bytes]Decompressing the image :### [OK]02:37:42:%SYS-5-RELOAD:Reload requested by console. Reload Reason:Reload Command.Restricted Rights Legend...Press RETURN to get started!00:00:12:%LINK-3-UPDOWN:Interface Ethernet5/0, changed state to up00:00:12:%LINK-3-UPDOWN:Interface Ethernet5/1, changed state to up00:00:12:%LINK-3-UPDOWN:Interface Ethernet5/2, changed state to up00:00:12:%LINK-3-UPDOWN:Interface Ethernet5/3, changed state to up00:00:12:%LINK-3-UPDOWN:Interface FastEthernet6/0, changed state to up00:00:12:%LINK-3-UPDOWN:Interface FastEthernet6/1, changed state to up00:00:12:%SYS-5-CONFIG_I:Configured from memory by console00:00:13:%SYS-5-RESTART:System restarted --00:00:13:%SYS-6-BOOTTIME:Time taken to reboot after reload = 25 seconds00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface Ethernet5/0, changed state to up00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface Ethernet5/1, changed state to down00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface Ethernet5/2, changed state to down00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface Ethernet5/3, changed state to down00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface FastEthernet6/0, changed state to down00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface FastEthernet6/1, changed state to down00:00:14:%LINEPROTO-5-UPDOWN:Line protocol on Interface Fddi4/0, changed state to down00:00:14:%LINK-5-CHANGED:Interface Fddi4/0, changed state to administratively down00:00:14:%LINK-5-CHANGED:Interface Ethernet5/1, changed state to administratively down00:00:14:%LINK-5-CHANGED:Interface Ethernet5/2, changed state to administratively down00:00:14:%LINK-5-CHANGED:Interface Ethernet5/3, changed state to administratively down00:00:14:%LINK-5-CHANGED:Interface FastEthernet6/0, changed state to administratively down00:00:14:%LINK-5-CHANGED:Interface FastEthernet6/1, changed state to administratively downAdditional References
The following sections provide references related to the Warm Upgrade feature.
Related Documents
Additional information on rebooting your router
The chapter "Rebooting" in the section "File Management" in the Cisco IOS Configuration Fundamentals and Network Management Configuration Guide, Release 12.3
Additional booting commands
Cisco IOS Configuration Fundamentals and Network Management Command Reference, Release 12.3T
Standards
MIBs
None
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
RFCs
Technical Assistance
Command Reference
This section documents new and modified commands only.
debug warm-reboot
To display warm reload debug information, use the debug warm-reboot command in privileged EXEC mode. To disable debugging output, use the no form of this command.
debug warm-reboot
no debug warm-reboot
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following is sample output from the reload warm file url command when the debug warm-reboot command is enabled:
Router# debug warm-rebootRouter# reload warm file tftp://9.1.0.1/c7200-p-mz.portProceed with reload? [confirm]Loading c7200-p-mz.port from 9.1.0.1 (via Ethernet5/0):!!!00:05:43:ptr :63B978E000:05:43:magic :A45727200:05:43:ptr :63B9802000:05:43:magic :000:05:43:ptr :63B9838000:05:43:magic :000:05:43:ptr :63B983A000:05:43:magic :FEEDFACE00:05:43:uncomp_size :2749E7C00:05:43:comp_size :E966F000:05:43:comp_checksum :9BB3605300:05:43:uncomp_checksum :56F1754B!!![OK - 15323964 bytes]Decompressing the image :###00:06:22:Image checksum correct -1#68274321300:06:22:Compressed Image checksum correct### [OK]Number 0 source 0x63BD17C4Number 1 source 0x63C43AD0Number 2 source 0x63C83AFCNumber 3 source 0x63CC3B28...Number 156 source 0x66384074Number 157 source 0x663C40A0Number 158 source 0x664040CCwrb_copy_and_launch location = 0x664040CC00:06:39:Found elf header at the expected location00:06:39:Source elf_hdr->e_shnum = A00:06:39:Setting up to copy ELF section 100:06:39: to image_info section 000:06:39: sh_name = B00:06:39: sh_type = 100:06:39: sh_flags = 700:06:39: sh_addr = 8000800000:06:39: sh_offset = 6000:06:39: sh_size = 186C00000:06:39: sh_link = 000:06:39: sh_info = 000:06:39: sh_addralign = 2000:06:39: sh_entsize = 0...00:06:40:Setting up to copy ELF section 400:06:40: to image_info section A000:06:40: sh_name = 1F00:06:40: sh_type = 100:06:40: sh_flags = 1000000300:06:40: sh_addr = 8275038000:06:40: sh_offset = 27483E000:06:40: sh_size = 18A000:06:40: sh_link = 000:06:40: sh_info = 000:06:40: sh_addralign = 1000:06:40: sh_entsize = 000:06:40:cpu type :1900:06:40:image_info->entry_point = 8000800000:06:40:image_info->section_count = A100:06:40:image_info->monstack = 80007FC000:06:40:image_info->monra = BFC014E400:06:40:image_info->param0 = 200:06:40:image_info->param1 = 000:06:40:image_info->param2 = 8000599800:06:40:image_info->param3 = 8000800000:06:40:Section00:06:40:SectionDecompressed Image checksum correctRestricted Rights Legend...reload
To reload the operating system, use the reload command in privileged EXEC mode.
reload [/verify | /noverify] [warm [file url]] [in [hh:]mm | at hh:mm [month day | day month]] [cancel] [text]
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The reload command halts the system. If the system is set to restart on error, it reboots itself. Use the reload command after configuration information is entered into a file and saved to the startup configuration.
You cannot reload from a virtual terminal if the system is not set up for automatic booting. This restriction prevents the system from dropping to the ROM monitor (ROMMON) and thereby taking the system out of the remote user's control.
If you modify your configuration file, the system prompts you to save the configuration. During a save operation, the system prompts whether you want to proceed with the save if the CONFIG_FILE variable points to a startup configuration file that no longer exists. If you say "yes" in this situation, the system enters setup mode upon reload.
When you schedule a reload to occur at a later time, it must take place within approximately 24 days.
The at keyword can be used only if the system clock has been set on the router (either through Network Time Protocol (NTP), the hardware calendar, or manually). The time is relative to the configured time zone on the router. To schedule reloads across several routers to occur simultaneously, the time on each router must be synchronized with NTP.
To display information about a scheduled reload, use the show reload EXEC command.
The /verify and /noverify Keywords
If the /verify keyword is specified, the integrity of the image will be verified before it is reloaded onto a router. If verification fails, the image reload will not occur. Image verification is important because it assures the user that the image is protected from accidental corruption, which can occur at any time during transit, starting from the moment the files are generated by Cisco until they reach the user.
The /noverify keyword overrides any global automatic image verification that may be enabled via the file verify auto command.
The warm Keyword
If you issue the reload command after you have configured the warm-reboot global configuration command, a cold reboot will occur. Thus, if you wish to reload your system, but do not want to override the warm reboot functionality, you should specify the warm keyword with the reload command. The warm reboot functionality allows a Cisco IOS image to reload without ROMMON intervention. That is, read-write data is saved in RAM during a cold startup and restored during a warm reboot. Warm rebooting allows the router to reboot quicker than conventional rebooting (where control is transferred to ROMMON and back to the image) because nothing is copied from flash to RAM.
Examples
The following example shows how to immediately reloads the software on the router:
Router# reloadThe following example shows how to reload the software on the router in 10 minutes:
Router# reload in 10Router# Reload scheduled for 11:57:08 PDT Fri Apr 21 1996 (in 10 minutes)Proceed with reload? [confirm]Router#The following example shows how to reload the software on the router at 1:00 p.m. today:
Router# reload at 13:00Router# Reload scheduled for 13:00:00 PDT Fri Apr 21 1996 (in 1 hour and 2 minutes)Proceed with reload? [confirm]Router#The following example shows how to reload the software on the router on April 20 at 2:00 a.m.:
Router# reload at 02:00 apr 20Router# Reload scheduled for 02:00:00 PDT Sat Apr 20 1996 (in 38 hours and 9 minutes)Proceed with reload? [confirm]Router#The following example shows how to cancel a pending reload:
Router# reload cancel%Reload cancelled.The following example shows how to perform a warm reboot at 4:00 today:
Router# reload warm at 4:00
The following example shows how to specify image verification via the /verify keyword before reloading an image onto the router:
Router# reload /verifyVerifying file integrity of bootflash:c7200-kboot-mz.121-8a.E%ERROR:Signature not found in file bootflash:c7200-kboot-mz.121-8a.E.Signature not present. Proceed with verify? [confirm]Verifying file disk0:c7200-js-mz ......................................................................................................................................Done!Embedded Hash MD5 :CFA258948C4ECE52085DCF428A426DCDComputed Hash MD5 :CFA258948C4ECE52085DCF428A426DCDCCO Hash MD5 :44A7B9BDDD9638128C35528466318183Signature VerifiedProceed with reload? [confirm]nRouter#
Related Commands
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