Resolving UFS File System Inconsistencies (Tasks)

This chapter describes the fsck error messages and the possible responses you can make to resolve the error messages.

This is a list of the information in this chapter.

• General fsck Error Messages

• Initialization Phase fsck Messages

• Phase 1: Check Blocks and Sizes Messages

• Phase 1B: Rescan for More DUPS Messages

• Phase 2: Check Path Names Messages

• Phase 3: Check Connectivity Messages

• Phase 4: Check Reference Counts Messages

• Phase 5: Check Cylinder Groups Messages

• Cleanup Phase Messages

For information about the fsck command and how to use it to check file system integrity, see "Checking UFS File System Consistency (Tasks)" in System Administration Guide: Basic Administration.

fsck Error Messages

Normally, the fsck command is run non-interactively to preen the file systems after an abrupt system halt in which the latest file system changes were not written to disk. Preening automatically fixes any basic file system inconsistencies and does not try to repair more serious errors. While preening a file system, the fsck command fixes the inconsistencies it expects from such an abrupt halt. For more serious conditions, the command reports the error and terminates.

When you run the fsck command interactively, it reports each inconsistency found and fixes innocuous errors. However, for more serious errors, the command reports the inconsistency and prompts you to choose a response. When you run the fsck command with the -y or -n options, your response is predefined as yes or no to the default response suggested by the fsck command for each error condition.

Some corrective actions will result in some loss of data. The amount and severity of data loss might be determined from the fsck diagnostic output.

The fsck command is a multipass file system check program. Each pass invokes a different phase of the fsck command with different sets of messages. After initialization, the fsck command performs successive passes over each file system, checking blocks and sizes, path names, connectivity, reference counts, and the map of free blocks (possibly rebuilding it). It also performs some cleanup.

The phases (passes) performed by the UFS version of the fsck command are:

• Initialization

• Phase 1 - Check blocks and sizes

• Phase 2 - Check path names

• Phase 3 - Check connectivity

• Phase 4 - Check reference counts

• Phase 5 - Check cylinder groups

The next sections describe the error conditions that might be detected in each phase, the messages and prompts that result, and possible responses you can make.

Messages that might appear in more than one phase are described in General fsck Error Messages. Otherwise, messages are organized alphabetically by the phases in which they occur.

The following table lists many of the abbreviations included in the fsck error messages.

Table 32-1 Error Message Abbreviations

Many of the messages also include variable fields, such as inode numbers, which are represented in this book by an italicized term, such as inode-number. For example, this screen message:

INCORRECT BLOCK COUNT I=2529 

is shown as follows:

INCORRECT BLOCK COUNT I=inode-number

General fsck Error Messages

The error messages in this section might be displayed in any phase after initialization. Although they offer the option to continue, it is generally best to regard them as fatal. They reflect a serious system failure and should be handled immediately. When confronted with such a message, terminate the program by entering n(o). If you cannot determine what caused the problem, contact your local service provider or another qualified person.

CANNOT SEEK: BLK block-number (CONTINUE)

Cause

A request to move to a specified block number, block-number, in the file system failed. This message indicates a serious problem, probably a hardware failure.

If you want to continue the file system check, fsck will retry the move and display a list of sector numbers that could not be moved. If the block was part of the virtual memory buffer cache, fsck will terminate with a fatal I/O error message.

Action

If the disk is experiencing hardware problems, the problem will persist. Run fsck again to recheck the file system.

If the recheck fails, contact your local service provider or another qualified person.

CANNOT READ: BLK block-number (CONTINUE)

Cause

A request to read a specified block number, block-number, in the file system failed. The message indicates a serious problem, probably a hardware failure.

If you want to continue the file system check, fsck will retry the read and display a list of sector numbers that could not be read. If the block was part of the virtual memory buffer cache, fsck will terminate with a fatal I/O error message. If fsck tries to write back one of the blocks on which the read failed, it will display the following message:

WRITING ZERO'ED BLOCK sector-numbers TO DISK

Action

If the disk is experiencing hardware problems, the problem will persist. Run fsck again to recheck the file system. If the recheck fails, contact your local service provider or another qualified person.

CANNOT WRITE: BLK block-number (CONTINUE)