This document covers the use of the fsck (file system check) command in Maintenance mode to repair inconsistencies in file systems. The procedure described is useful when file system corruption in the primary root file systems is suspected or, in many cases, to correct an IPL hang at LED value 518 or LED value 555.
This document applies to AIX V4.
Please refer to your system user's or installation and service guide for specific IPL procedures related to your type and model of hardware. You can also refer to the document titled "Booting in Service Mode," available at http://techsupport.services.ibm.com/rs6k/techbrowse/.
Follow the screen prompts to the following menu:
Welcome to Base Operating System Installation and Maintenance
The next screen displays the Maintenance menu.
The next screen displays a warning that indicates you will not be able to return to the Base OS menu without rebooting.
The next screen displays information about all volume groups on the system.
If you get errors from the preceding option, do not continue with the rest of this procedure. Correct the problem causing the error. If you need assistance correcting the problem causing the error, contact one of the following:
If no errors occur, proceed with the following steps.
NOTE: The -y option gives fsck permission to repair file system corruption when necessary. This flag can be used to avoid having to manually answer multiple confirmation prompts, however, use of this flag can cause permanent, unnecessary data loss in some situations.
fsck /dev/hd4 fsck /dev/hd2 fsck /dev/hd3 fsck /dev/hd9var fsck /dev/hd1
Answer yes when asked if you want to destroy the log.
mount /dev/hd4 /mnt mv /mnt/etc/filesystems /mnt/etc/filesystems.[MMDDYY] cp /etc/filesystems /mnt/etc/filesystems umount /mnt
MMDDYY represents the current two-digit representation of the Month, Day and Year, respectively.
LVname is the name of your user-defined logical volume.
imfs -l /dev/[LVname]
varyonvg [VGname] fsck /dev/[LVname]
VGname is the name of your user-defined volume group.
The preceding commands can be repeated for each user-defined volume group on the system.
The file /etc/filesystems.MMDDYY saved in the preceding steps may be used as a reference if it is readable. However, the imfs method is preferred since it uses information stored in the logical volume control block to re-populate the /etc/filesystems file.
If your system still halts at the LED 518 display, in many cases, it is faster and more cost-effective to reinstall from a recent system backup. Attempting to isolate the cause of the problem can be very time-consuming and often results in the determination that a reinstall is required to correct the problem anyway.
If you need assistance correcting the problem causing the halt, contact one of the following:
[ Doc Ref: 90605188914738 Publish Date: Nov. 06, 2000 4FAX Ref: 2535 ]