About Filesystem Serviceability Enhancements in AIX Versions 4 and 5

About this document

• AIX Version 4.3 System Management Guide: Operating System and Devices (SC23-2525)
• AIX Version 4.3 Commands Reference (reference for fsck), Volume 1

AIX RELEASE      APAR
------------------------------------
4.1.5            IX83878
4.2.1            IX82819 and IX84402
4.3.2            IX86362

The enhancements are evident in three areas.

First, there is a new error code, ECORRUPT (return code 89). This value is returned to an application from a filesystem system call when non-fatal (for example, directory) filesystem corruption is detected.

Second, new filesystem error log entries have been added. There are two classes of new entries.

1. Informational. These do not of themselves constitute an error condition. They are meant to alert the administrator to possible problems; they may require attention to prevent a problem from occurring.
2. Diagnostic. These indicate that a problem has occurred. They are intended to pinpoint the resource on which a problem has occurred and what kind of problem has occurred. A service representative may need to be contacted to pursue these when they occur.

In AIX 4.1.5 and 4.3.2, the message returned by perror() for ECORRUPT is Reserved errno was encountered. In AIX 4.2.1 and all future releases beyond AIX 4.3.2, the message returned by perror() for ECORRUPT is Invalid filesystem control data detected.

Third, the system dump facility has been enhanced to include extensive filesystem dump information only when a filesystem-related crash has been detected. In the case of a filesystem-related dump, more information will be present in the dump to help diagnose the cause. If the crash is not filesystem related, the amount of filesystem-related information present in the dump will be reduced. This will generally result in smaller dumps.

When you receive one of the new error log entries in your error report, refer to the following list for an explanation of each new error type and possible actions to take.

Error Description: SPECFS_DDINTPRI                   Error ID: AE26DD07
This error is logged when a call to a device driver returns with system interrupts disabled. A system crash will accompany this. The owner of the device driver should investigate the cause.

Error Description: JFS_USER_HARDLINK            Error ID: 5ECE4A58
This error is logged when a hard link is created to or removed from a directory. This error is intended as a warning since such operations can result in filesystem corruption or strange filesystem behavior.

Only an entity with superuser privileges can perform these kinds of hard links.

Error Description: JFS_USER_WRITEMOUNT      Error ID: D73189F6
This error is logged when a process writes directly to a logical volume while a filesystem on that logical volume is mounted.

Unmount the filesystem and run fsck to ensure filesystem integrity. fsck can also be run with the -d option specifying a block (as indicated from the full error entry) to determine what file, if any, may have been affected.

Error Description: JFS_FS_FULL                               Error ID: 369D049B
This error is logged when no free space exists within a filesystem. This error is logged only once per filesystem mount or filesystem extension.

Error Description: JFS_FS_FRAGMENTED            Error ID: 5DFED6F1
This error is logged when insufficient contiguous free space exists to fulfill an allocation request within a filesystem. This error should only apply to filesystems created with a fragment size less than 4K or a large-file-enabled filesystem.

Run the defragfs command on the affected filesystem to defragment the filesystem free space. This error is logged once per filesystem mount or filesystem extension.

Error Description: JFS_FS_NOINODES                   Error ID: 8988389F
This error is logged when all of the inodes allocated to a filesystem are exhausted. To resolve the problem, remove or relocate inactive files within the filesystem to another filesystem. Alternatively, increase the filesystem size to supply more inodes. If more inodes are needed within the specified size of the filesystem, then the filesystem may need to be recreated with a smaller NBPI value to increase the number of inodes for this filesystem.

Error Description: JFS_KERNHEAP_LOW             Error ID: 83F4B3CB
This error is logged if a kernel memory request is unsuccessful. This error will be logged no more than once per 24-hour period of system uptime. Contact an appropriate service representative.

Error Description: JFS_KERNHEAP_DELAY        Error ID: 7975092C
This error is logged if a kernel memory request had a previous failure but succeeded on a retry. This error will be logged no more than once per 24-hour period of system uptime. This error is merely a warning, but may result in a JFS_KERNHEAP_LOW error if the condition continues. Contact an appropriate service representative.