This document discusses the process by which an RS/6000 system can be booted into service mode (also known as maintenance mode) to install the machine, restore an operating system backup, or perform maintenance on the rootvg volume group.
The information in this document applies to AIX Versions 3.x and 4.x.
For more in-depth coverage of this subject, the following IBM publication is recommended:
IBM documentation can also be accessed online through the following URL:
Similar documents can be accessed through the following URL:
To boot microchannel systems into service mode, turn the key to the maintenance position and press the yellow reset button twice. You must boot from bootable media, such as an installation CD-ROM, installation tape, or a bootable backup tape made via the mksysb command or the Sysback product of the correct level for this machine.
For AIX Version 3.2, you may use bootable bosboot diskettes. To boot from these, insert the first (bosboot) diskette into the diskette drive. When you see LED c07, insert the next diskette, which is usually the display extensions diskette. After this diskette is read, you should receive a menu prompting you for the installation diskette.
For information on accessing your rootvg volume group, see the section entitled "Accessing rootvg and Mounting File Systems".
All of the preceding discussion assumes that the service mode bootlist has not been modified from the default bootlist. If so, it needs to be reset such that one of the boot media types from the preceding selections is before the standard boot media, such as the hard disk.
If the machine is an SMP model (7012-Gxx, 7013-Jxx, and 7015-Rxx) and the Autoservice IPL flag is disabled, then a menu like the following will display when it is booting in service mode:
MAINTENANCE MENU (Rev. 04.03) 0> DISPLAY CONFIGURATION 1> DISPLAY BUMP ERROR LOG 2> ENABLE SERVICE CONSOLE 3> DISABLE SERVICE CONSOLE 4> RESET 5> POWER OFF 6> SYSTEM BOOT 7> OFF-LINE TESTS 8> SET PARAMETERS 9> SET NATIONAL LANGUAGE SELECT:
Choose the SYSTEM BOOT option and then select the BOOT FROM LIST option from the subsequent menu.
When booting an RS/6000 PowerPC system into service mode, you must either have cd0 or rmt0 in the bootlist before your hdisk, or change the bootlist at boot time. On some models, you can set the machine to use a default bootlist that includes both cd0 and rmt0. If a bootable CD or tape is in the CD-ROM Sr tape drive, the machine will boot from this device.
For most of the newer PCI-based models, selecting the default bootlist, with a bootable tape or CD loaded in the machine, causes the system to automatically boot from that device. Generally, the next menu on the screen asks the administrator to define the system console.
Note that for all machines discussed here, if you are using a graphical terminal, you will use a function key, such as F2. If you are using an ASCII terminal, use an equivalent number key, such as 2 (the number 2 near the left side of the keyboard, not the 2 on the number pad). On ASCII terminals, the icons may not be displayed on the screen; the number can be pressed between the second and third beeps (the second beep being a series of 3 clicks).
The following systems all use the F5 or 5 key to read from the default boot list, which is written into the system firmware:
MODEL 7017 7024 7025 7026 7043 7137 ------- ------- ------- ------- ------- ------- ------- TYPE S70 E20 F30 H10 43P-140 F3L S7A E30 F40 H50 43P-150 F50 H70 43P-240 43P-260
On these machines, use 5 (on the keyboard, not the keypad) if you are using an ASCII terminal. On a locally attached graphics console, use the F5 function key. The F5 or 5 key must be pressed just after the keyboard icon or message is displayed on the console.
The following systems use the F1 key to enter System Management Mode (SMS):
MODEL 6040 7042 7247 7249 ------- ------- ------- ------- ------- TYPE 620 850 82x 860
You should be in an Easy-Setup menu. Select the Start Up menu. Clear the current bootlist settings and then select the CD-ROM for choice 1 and hdd (the hard disk) for choice 2. Select OK. Insert the CD-ROM and select the EXIT icon. The machine should now boot from the CD-ROM.
The following systems use the F2 key to enter SMS:
MODEL 6015 6050 6070 7020 7248 ------- ------- ------- ------- ------- ------- TYPE 440 830 850 40P 43P
Select Select Boot Device from the initial menu on the screen, and then select Restore Default Settings from the list. Press the Esc key to exit all the menus, and then reboot the machine. The system should boot from your bootable media.
For information on accessing your rootvg volume group, see the next section in this document.
For AIX Version 3, choose the limited function maintenance shell (Option 5 for AIX 3.1, Option 4 for AIX 3.2).
If you only have one disk on the system, then hdisk0 will be used in the execution of the getrootfs or /etc/continue commands, which follow. If you have more than one disk, determine which disk contains the boot logical volume in this manner:
AIX 3.2.4 or AIX 3.2.5:
Run getrootfs; the output will indicate which disk contains the hd5 logical volume.
AIX 3.1 to AIX 3.2.3e:
Run lqueryvg -Ltp hdisk# for each hdisk. You can obtain a listing of these with lsdev -Cc disk until you get output SIMILAR to:
00005264feb3631c.2 hd5 1If more than one disk contains this output, you can use any disk when running getrootfs.
Now, access the rootvg volume group by running one of the following commands, using the disk you obtained in the preceding step:
AIX 3.1: /etc/continue hdisk# AIX 3.2.0-3.2.3e: getrootfs -f hdisk# AIX 3.2.4-3.2.5: getrootfs hdisk#
NOTE: If you want to leave the primary OS file systems (/, /usr, /tmp, and /var) unmounted after this command has completed (in order to run fsck, for instance), place a space and the letters sh after the hdisk in the preceding command. For example:
getrootfs hdisk0 shFor AIX Version 4, choose Start Maintenance Mode for System Recovery (option 3). The next screen will be called Maintenance; select option 1 (Access a Root Volume Group). At the next screen, type 0 to continue, and select the appropriate volume group by typing the number next to it. A screen like the following will display.
Access a Root Volume Group
Type the number for a volume group to display the logical volume information and press Enter.
1) Volume Group 0073656f2608e46a contains these disks: hdisk0 2063 04-C0-00-4,0
Once a volume group has been selected, information will be displayed about that volume group.
Volume Group Information ------------------------------------------------------------------------------ Volume Group ID 0073656f2608e46a includes the following logical volumes: hd6 hd5 hd8 hd4 hd2 hd9var hd3 hd1 ------------------------------------------------------------------------------
Type the number of your choice and press Enter.
1) Access this Volume Group and start a shell 2) Access this Volume Group and start a shell before mounting filesystems 99) Previous Menu
If the logical volumes listed do not include logical volumes like hd4, hd2, hd3, and so on, you may have selected the wrong volume group. You can hit 99 to back up one screen and select again.
Now you may select one of two options: Access this volume group and start a shell (Option 1), or Access this volume group and start a shell before mounting file systems (Option 2). Option 2 allows you to perform file system maintenance on /, /usr, /tmp, and /var before mounting them.
Errors from these steps may indicate failed or corrupt disks in rootvg. You should correct these problems. For additional assistance, contact your vendor, your local branch office, or your AIX support center.