AIX and FIRMWARE LIMITATION CAN PROHIBIT SYSTEM BOOT WHEN KERNEL IS GREATER THAN 12MB
This document describes a system boot and recovery limitation in the system firmware and AIX. Please read this entire document before implementing any of its suggestions.
HOW TO CONFIRM THAT THE BOOT PROBLEM REALTES TO A > 12MB KERNEL
The system will fail to boot from the SysBack tape. Common failure symptoms are error code 20EE000B displayed on the LCD display or text on the system console containing the words "default catch" and on the screen. Error code 20EE000B means that "The system was not able to find an operating system on the device list that was attempted."
Additionally, 7028,7029,7038 and 7040 with recent levels of system firmware installed will display error 20EE000A. Error code 20EE000A means that "The image size on the boot/install device exceeds system firmware memory limitations."
A potential cause for these symptoms is that the boot image on the media is larger than 12Mb. This condition is only known to occur on systems with AIX 5.1 or 5.2 installed. This symptom can be experienced on any CHRP system. AIX and IBM Hardware architects are working to deliver a permanent fix to this issue. Until the solution is available, please use the below instructions as a workaround to this issue.
ADDITIONAL PROBLEM CONFIRMATION ACTIONS:
If you have access to the backup logs on the system that created SysBack tape, you could look for this information as well:
Changing tape block size to 512 ..
Placing boot image on tape ..
bosboot: Boot image is 22251 512 byte blocks.
See that the boot image size above is 22251, if that number is greater than 24576 then your bootimage is greater than 12MB and you are experiencing this problem.
Although this problem has only been documented for tape boot as of the publishing of this document, there is a slight chance that you could encounter the same problem with CD, DVD, or network boot. The size of the boot image created for the CD, DVD, and Network Boot types is considerably smaller than that of the tape boot type in most cases. Therefore, booting from these alternative options makes it highly unlikely that you could encounter this issue. The smallest of the boot type boot images is the Network Boot image and therefor the least likely to experience this issue. In a future AIX PTF, the bosboot command will issue a warning message in the event that a boot image is created that exceeds this size limitation. Once this PTF is available, this document will be updated with the PTF numbers. Please monitor your backup, boot only media creation, and network boot configuration process output for indications that you have reached or exceeded this limit.
It is essential that you monitor process output for the following processes and verify that the boot image placed on the media is not larger than "24576 512 byte blocks:
- Full System (Installation Image Backup) via the /usr/sbin/sysback command
- Creating a"Boot Only Tape" via the /usr/sbin/sysback
- Creating a "Boot Only CD/DVD" via the /usr/sbin/mksbcd commands
- Creating or updating a Network Boot image via the /usr/sbin/mksbnetbooot command
HOW TO PREPARE FOR CD/DVD BOOT
To generate a boot only DVD (with no backup data) to the /dev/cd1 device, issue:
1. mksbcd -B -T "D" -f /dev/cd1
2. Boot your system from this media and go to the section of this document titled "AFTER BOOTING, HOW TO INSTALL"
*Note: This assumes that /dev/cd1 is allocated to the partition that will be creating the media or physically attached to the machine creating the media.
If you are creating a CD, replace the "D" with a "C". Change the "/dev/cd1" to the device name for your system.
You will need the following GNU software tools to create a SysBack bootable CD or DVD:
mkisofs and readcd which are included in the GNU cdrecord and cdrtools packages.
These tools may be obtained from the AIX for Linux Toolbox CD, download them
or download them from the internet website of your choice. IBM and Tivoli does
not support these code packages.
HOW TO PREPARE FOR NETWORK BOOT
If the CD / DVD device can not be allocated to the partition or machine that will be recovered.....
Perform these steps on a machine that has the EXACT and every device driver required for the boot of the client machine. Preferably, another p690 LPAR in the same, or different machine. If you use a non-LPAR system, there are special preparations required. These are detailed in Chapter 13. Network Boot/Installation Configuration in the SysBack User's Guide which is located here: http://publib.boulder.ibm.com/tividd/td/StorageMangerforSysback5.6.html
1. mksbnetboot -h client_hostname -d ethernet -T chrp -k mp -S ip_address_of_this_machine_aka_boot_server -g gateway_IP_address -s subnet_mask
NOTE: If the client and the boot server are on the same subnet, you must enter the server IP address again with the "-g". Otherwise, enter the IP address of the gateway / router.
You must also configure remote services on the machine / partition to be the boot / install server.
3. cfgremaccess -h all -u all -f all
4. Boot your system from this media and go to the section of this document titled "AFTER BOOTING, HOW TO INSTALL"
AFTER BOOTING, HOW TO INSTALL
1. Perform either the network boot or the CD/DVD boot as you normally would with SysBack.
2. Once you are at the SYSBACK INSTALLATION AND MAINTENANCE MAIN MENU, select the option to "Change the installation device",
3. Select the tape device that has the SysBack backup.
4. Use the ESC key to return one menu.
5. Select the option CHANGE VOLUME GROUP AND LOGICAL VOLUME INFORMATION. This will position the tape to the correct place and skip the boot images already there.
6. You do not have to change any options in these menus. Simply press ESC to return to the main menu.
7. Select the option INSTALL THE SYSTEM WITH CURRENT SETTINGS.
NOTE: If you choose to network boot, you will have to access SMS to enter the bootp information just like you would for a NIM boot.
ADDITIONAL INFORMATION RESOURCES
The following redbook has a chapter on how to use SysBack in a partitioned environment has detailed explanations of how to network boot LPARs, create backups, etc. Look for the chapter entitled: Partition backup, recovery, and cloning using SysBack.
You may also find the latest SysBack Tips and Hints online at
For additional detailed configuration options, please contract support by calling 1-800-IBMSERV and ask to speak with the SysBack support team.
More support for:
Tivoli Storage Manager for System Backup and Recovery
Software version: 5.1, 5.2, 5.3, 5.4, 5.5, 5.6
Operating system(s): AIX
Software edition: All Editions
Reference #: 1144054
Modified date: 17 August 2009